There are five significant figures in the measurement 0.023040 cm.
To determine the number of significant figures in a given measurement, one must follow these rules:
1. Non-zero digits are always significant. In the measurement 0.023040 cm, the digits 2, 3, and 4 are non-zero and thus significant.
2. Zeros between non-zero digits are significant. Here, the zero between the 3 and the 4 is significant because it is sandwiched between two non-zero digits.
3. Leading zeros, which are zeros before the first non-zero digit in a number less than one, are not significant. In this case, the two zeros after the decimal point and before the 2 are leading zeros and are not significant.
4. Trailing zeros, which are zeros at the end of a number, are significant if the number has a decimal point. In the measurement 0.023040 cm, the zero at the end is after the decimal point and is therefore significant.
Applying these rules, we count the significant figures in 0.023040 cm as follows:
- The first two zeros after the decimal point are not significant (leading zeros).
- The digit 2 is significant.
- The digit 3 is significant.
- The zero between the 3 and the 4 is significant (it is between two non-zero digits).
- The digit 4 is significant.
- The last zero is significant (trailing zero after the decimal point).
Therefore, the measurement 0.023040 cm has five significant figures.
help plz .....................................................................................
Answer:
D.
Explanation:
Energy is released after reaction, so this is exothermic reaction. D
Answer:
D
Explanation:
First of all, the reaction is exothermic. The equation is not normally written this way. The way it is written shows that energy is given off: the heat is a product. The only answer that is described is D
Exothermic (but oddly presented) and energy given off.
Air, not water, is the compound of life.
a. True
b. False
Answer:
Air is a mixture of carbon dioxide, hydrogen and oxygen so it's a MIXTURE and NOT a COMPOUND.
Final answer:
The statement is false as water is the compound essential for all forms of life, not air.
Explanation:
The statement 'Air, not water, is the compound of life' is false. Water is a compound made up of hydrogen and oxygen and is essential for all forms of life on Earth. Water's unique properties, such as its polarity and its ability to stabilize temperature, make it indispensable for living organisms. For instance, it participates in chemical reactions within cells, helps with temperature regulation, and is a solvent for nutrients. While air is also important, providing oxygen for respiration, it is not considered a compound. Moreover, water, not air, is the most abundant molecule in Earth's atmosphere.
50 points and will mark brainiest!!!
1. Mary bought an apple for lunch. She found the weight of the apple on the spring scale in the store and estimated how much her apple would cost. When she got home she washed the apple, cut it in half, and placed it in a zip-lock bag. Mary refrigerated the apple over night. The next morning the apple, was crisp, cold, and the cut surfaces had turned brown.
Mary cut the apple in half is an example of
A) sublimation.
B) a chemical change.
C) a physical change.
D) a change of state.
2. Which statement best describes the nuclear model of the atom?
A) negative charges dispersed in a positively charged cloud
B) positive charges dispersed in a negatively charged cloud
C) small, dense positive nucleus surrounded by a diffuse negatively charged cloud
D) small, dense negative nucleus surrounded by a diffuse positively charged cloud
3. Which of these elements would have the largest atomic radius? (picture at the bottom)
A) C
B) F
C) Li
D) Ne
C)
C)
D)...... ..........
Answer:
Explanation:
First one is C. It is not using chemicals to break in half, instead she is physically cutting the apple herself. Therefore , she is physically cutting the apple. Not sure on number two sorry. Hope this helps!
~ HAZEL360
An organism had 1,000 grams of carbon-14 (a radioactive form of carbon) in it when it died. How much remains after five half-lives?
Answer:
After 5th half life the remaining mass is 31.25 g.
Explanation:
Given data:
Total mass of carbon-14 = 1000 g
Mass remain after 5 half lives = ?
Solution:
At time zero = 1000 g
At first half life = 1000 g/2 = 500 g
At second half life = 500 g/ 2= 250 g
At third half life = 250 g/ 2 = 125 g
At 4th half life = 125 g/2 = 62.5 g
At 5th half life = 62.5 g/2 = 31.25 g
Thus after 5th half life the remaining mass is 31.25 g.
Nuclear reactions in a reactor produce a lot of thermal
energy. That energy then flows and warms up water, which
boils and produces steam. The steam then turns turbines
that generate electricity
Which statement below can be made about the production
of electricity in a nuclear reactor?
Heat flows in the form of electricity
Heat flows from the reactor to the water.
The water produces heat.
The steam produces heat
Mark this and return
Save and Exit
Next
Subu
Answer:
Heat flows from the reactor to the water
Explanation:
The thermal energy mentioned in the description is another way to say heat. The energy that is produced by the nuclear reactions leaves the reactor and enters the water, warming it.
The passage does not say that heat flows in the form of electricity, but rather that the turbines turned by the steam produce electricity.
The passage does not say that the steam produces the heat, but rather that the boiling of the water (caused by the heat) produces steam.
Answer:
B
Explanation:
Choose the correct answers from the drop-down menus to complete the paragraph about how sunlight travels through the atmosphere.
Sunlight can be absorbed, , or scattered before it reaches Earth’s surface. About 30 percent of sunlight hits Earth directly, and 22 percent is filtered through . Dust particles short wavelengths, which causes the sky to appear blue. Earth radiates heat into the atmosphere, which traps the heat in gases, causing the .
Answer: reflected, clouds, greenhouse effect.
Explanation:
Sunlight can be absorbed, reflected , or scattered before it reaches Earth’s surface. About 30 percent of sunlight hits Earth directly, and 22 percent is filtered through clouds . Dust particles scatter short wavelengths, which causes the sky to appear blue. Earth radiates heat into the atmosphere, which traps the heat in gases, causing the greenhouse effect.
According to the context, the missing words to correctly complete the paragraph are the following:
Sunlight can be reflected or scattered before it reaches Earth's surface. About 30 percent of sunlight hits Earth directly, and 22 percent is filtered through clouds. Dust particles scatter short wavelengths, which causes the sky to appear blue. Earth radiates heat into the atmosphere, which traps the heat in gases, causing the greenhouse effect.
How sunlight travels through the atmosphere?The Sun is the main source of energy for all the processes that occur in the earth - atmosphere - ocean system.
Sunlight passing through the atmosphere undergoes a weakening process due to scattering (due to aerosols), reflection by clouds and absorption by gas molecules and suspended particles.
Consequently, gases in the atmosphere that absorb infrared radiation from the Earth or outgoing radiation are known as greenhouse gases.
Therefore, we can conclude that sunlight passing through the atmosphere undergoes a weakening process due to scattering, reflection by clouds and absorption.
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find the POH of a solution of H3PO4 having a concentration of 0.05M
Answer:
The pOH of the solution is 13.176
Explanation:
The concentration of [tex]H_{3}PO_{4}[/tex] solution is 0.05 M
[tex]H_{3}PO_{4}[/tex] produces [tex]3\:H^{+}\:ions\:[/tex].
[tex]H_{3}PO_{4}\longrightarrow3H^{+}+PO_{4}^{3-}[/tex]
If the concentration of [tex]H_{3}PO_{4}[/tex] is 0.05 M, then the concentration of [tex]H^{+}\:ions\:[/tex] is three times that of [tex]H_{3}PO_{4}[/tex].
[tex][H^{+}]=3\times0.05=0.15M[/tex]
pH =-㏒([tex][H^{+}][/tex])= -㏒(0.15) =0.824
pOH = 14 - pH = 13.176
When K+ and I- combine, a(n) _________ bond results. A) covalent B) ionic C) metallic D) polyatomic
Answer:
B
Explanation:
A sample of metal with a mass of 350.0 g is heated to 100.0 ºC and dropped into 400.0 g of water at 21.4 ºC. The temperature of the water rises to 28.0 ºC. Assume there is no heat lost to the environment. Use the correct number of significant figures in your answer. What is the amount of heat gained by the water?
Answer:
1.1 x 10^4 J
Explanation:
Final answer:
The heat gained by the water when a metal sample is dropped into it can be determined using the formula q = mcΔT. For the given scenario, the water gains approximately 11000 J of heat.
Explanation:
To calculate the amount of heat gained by the water when a sample of metal is dropped into it, we can use the formula q = mcΔT, where q is the heat absorbed or released, m is the mass of the substance, c is the specific heat capacity, and ΔT is the change in temperature.
For water, the specific heat capacity (c) is typically 4.184 J/g°C.
In this case, the water's mass (m) is 400.0 g and the change in temperature (ΔT) is 28.0 °C - 21.4 °C = 6.6 °C.
Using the formula, we get q = 400.0 g × 4.184 J/g°C × 6.6 °C, which equals approximately 11016 J.
Since the question specifies to use the correct number of significant figures, we report the answer as 11000 J of heat gained by the water.
Calculate the specific heat of a metallic element if 50.0 g of the metal need 314 joules of heat energy to raise
the temperature from 25°C to 50°C.
Answer:
c = 0.25 j/g.°C
Explanation:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
Given data:
Mass of metal = 50.0 g
Heat needed = 314 j
Initial temperature = 25°C
Final temperature = 50 °C
Specific heat = ?
Solution:
ΔT = 50 °C - 25°C = 25°C
Q = m.c. ΔT
c = Q / m. ΔT
c = 314 j / 50.0 g . 25°C
c = 314 j / 1250 g. °C
c = 0.25 j/g.°C
Final answer:
The specific heat of the metallic element is calculated using the formula q = m x c x ΔT and for the provided values, it is found to be 0.2512 J/g°C.
Explanation:
To calculate the specific heat of a metallic element, we use the formula q = m × c × ΔT, where q is the heat energy transferred, m is the mass of the substance, c is the specific heat capacity, and ΔT is the change in temperature. Given 50.0 g of the metal, 314 joules of heat, and a temperature change from 25°C to 50°C, we can rearrange the formula to solve for c: c = q / (m × ΔT).
The change in temperature (ΔT) is 50°C - 25°C = 25°C. Thus, the specific heat (c) can be calculated as follows:
c = 314 J / (50.0 g × 25°C)
= 314 J / (1250 g°C)
= 0.2512 J/g°C
Therefore, the specific heat of the metallic element is 0.2512 J/g°C.
Calculate to three significant digits the density of boron trifluoride gas at exactly 20 C and exactly 1atm . You can assume boron trifluoride gas behaves as an ideal gas under these conditions.
Answer:
0.5583 g/L[/tex]
Explanation:
Since boron trifluoride ( B[tex]F_{3}[/tex] ) Is an ideal gas , we can apply IDEAL GAS EQUATION which is ,
PV = nRT
Where ,
P - the pressure at which it is present (20 atm)
V - volume of the gas (needed)
n - number of moles of the gas taken (1 mol)
R - universal gas constant which is 8.314 [tex]JK^{-1} mol^{-1}[/tex]
T - temperature of the gas ( 273 + 20 = 298 K )
thus ,
[tex]20*V = 1*8.314*293\\V= 121.8001 L[/tex]
density ρ = [tex]\frac{mass}{volume}[/tex]
mass of B[tex]F_{3}[/tex] is :
B : 11
F : 19
therefore , mass = 11 + [tex]3*19[/tex]
=68 g
density = [tex]\frac{68}{121.8001} = 0.5583 g/L[/tex]
Boron has a very high melting point of 4,000 degrees Fahrenheit and a very low density of 2.37 grams per cubic centimeter.
How do you compute an element's density?To Calculate Density using the Density Formula.
The density calculation formula is p = m/V,
= 0.5583 g/L
An ideal gas, boron trifluoride (B) can be estimated by utilizing the ideal gas equation, which exists,
PV = nRT
Where, P stands for the pressure at which it exists.
V exists the gas's volume.
N exists the quantity of moles of gas consumed.
R exists the 8.314 universal gas constant.
T exist the gas's temperature (273 + 20 = 298 K).
If density = mass of B, then:
B : 11 and F : 19
Consequently, mass = 11 + = 68 g.
Boron has a very high melting point of 4,000 degrees Fahrenheit and a very low density of 2.37 grams per cubic centimeter.
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How many atoms of lead are contained in 0.532mol?
Answer:
3.2043 x 10²³
Explanation:
No. of Mole of lead (Pb) = 0.532 mol
No. of atoms of lead = ?
Solution:
Formula Used to calculate
no. of moles = numbers of particles (ions, molecules, atoms) /Avogadro's number
Avogadro's no. = 6.023 x10²³
So,
The formula could be written as
no. of atoms of lead Pb = no. of moles x 6.023 x10²³
Put the values in above formula
no. of atoms of lead Pb = 0.532 mol x 6.023 x10²³
no. of atoms of lead Pb = 3.2043 x 10²³
so 3.2043 x 10²³ atoms of lead are contained in 0.532 mole.
Hydrogen-3 has a half-life of 12.32 years. A sample of H-3 weighing 3.02 grams is left for 15.0 years. What will the final weight of the H-3 sample be?
Answer:
[tex]\large \boxed{\text{1.38 g}}[/tex]
Explanation:
Two important formulas in radioactive decay are
[tex](1) \qquad t_{\frac{1}{2}} = \dfrac{\ln 2}{k}\\\\(2) \qquad \ln \left(\dfrac{N_{0}}{N}\right) = kt[/tex]
1. Calculate the decay constant k
[tex]\begin{array}{rcl}t_{\frac{1}{2}} &=& \dfrac{\ln 2}{k}\\\\\text{12.32 yr} &= &\dfrac{\ln 2}{k}\\\\k & = & \dfrac{\ln 2}{\text{12.32 yr}}\\\\& = & \text{0.056 26 yr}^{-1}\\\end{array}[/tex]
2. Calculate the mass remaining
[tex]\begin{array}{rcl}\ln \left(\dfrac{A_{0}}{A}\right) &= &kt \\\\\ln \left(\dfrac{\text{3.20 g}}{A}\right) &= &\text{0.056 26 yr}^{-1}\times \text{15 yr} \\\\\ln \left(\dfrac{\text{3.20 g}}{A}\right) &= &0.8439 \\\\\dfrac{\text{3.20 g}}{A} &= &e^{0.8439} \\\\\dfrac{\text{3.20 g}}{A}&= &2.325 \\\\A &= &\dfrac{\text{3.20 g}}{2.325}\\\\&= & \textbf{1.38 g}\\\end{array}\\\text{The final mass of the sample will be $\large \boxed{\textbf{1.38 g}}$}[/tex]
Answer: n = 1.30g
Explanation:
1. Suppose during volleyball practice, you lost 2.0 lbs of water due to sweating. If all of this
water evaporated, how much energy did the water absorb from your body? Express your
answer in kJ. (2.2 lbs = 1.0 kg)
Answer:
[tex]E=2052.8 kJ[/tex]
Explanation:
The energy absorbed by the water is the energy it requires to evaporate. So:
[tex] Heat of .vap= 40.65 kJ/mol[/tex]
The moles of water:
[tex]n_w=m_w *\frac{1000g}{2.2lbs}*\frac{1}{M}[/tex]
M is the water molecular weight
[tex]n_w=2 lbs *\frac{1000g}{2.2lbs}*\frac{1}{18g/mol}[/tex]
[tex]n_w=50.5mol[/tex]
The energy absorbed:
[tex]E=n_w*Heat of vap.=50.5mol *40.65 kJ/mol[/tex]
[tex]E=2052.8 kJ[/tex]
Recall the pancake recipe: 1 cup flour + 2 eggs + ½ tsp baking powder → 5 pancakes Suppose there are 5 cups of flour, 12 eggs, and 4 tsp. of baking powder. How many pancakes can be made?
Answer:
25 pancakes can be made.
Explanation:
This is a question based on the concept on of limiting reagent or limiting factor.
The pancakes can be kept on making till one of the item gets exhausted.
Let's, check which item gets exhausted first-
5 cups of flours are sufficient for making- [tex]\frac{5}{1}[/tex] × 5 ie. 25 pancakes considering we have 5×2 ie. 10 eggs and 5×1/2 ie. e 2.5 tsp of baking powder.
We can see that, we have all the required material needed and only the flour gets exhausted first.
But, still for our satisfaction we can check once, 12 eggs will make [tex]\frac{12}{2}[/tex] × 5 ie. 30 pancakes, but we don't have flour for 30 of them.
Similarly, 4 tsp of baking powder will yield 40 pancakes but we neither have enough flour nor we have enough eggs for it.
Therefore, the maximum number of pancakes that can be made are is 25.
Final answer:
The maximum number of pancakes that can be created with 5 cups of flour, 12 eggs, and 4 teaspoons of baking powder is 25. Flour is the limiting ingredient in this scenario, determining the final count of pancakes.
Explanation:
When considering how many pancakes can be made with given amounts of ingredients, we must determine the limiting reactant, much like in a stoichiometric calculation in chemistry. The original pancake recipe calls for 1 cup of flour, 2 eggs, and rac{1}{2} teaspoon of baking powder to make 5 pancakes.
We are provided with 5 cups of flour, 12 eggs, and 4 teaspoons of baking powder. To find out the maximum number of pancakes we can make, we identify the ingredient that will run out first when making batches of 5 pancakes. Here are the calculations based on the recipe proportions:
Flour: 5 cups imes 5 pancakes = 25 pancakesEggs: 12 eggs imes rac{5}{2} pancakes per egg = 30 pancakesBaking powder: 4 teaspoons imes 10 pancakes per teaspoon = 40 pancakesThe ingredient that limits us here is the flour, which will only allow for the creation of 25 pancakes before it is used up. Therefore, the maximum number of pancakes that can be made with the ingredients on hand is 25.
Iron is extracted from iron oxide in the blast furnace. Calculate the maximum theoretical mass of iron that can be made from 100g of iron oxide
69.918 g
Explanation:We are given;
Mass of iron oxide as 100 gWe are supposed to determine the maximum theoretical yield of Iron from the blast furnace;
The equation for the reaction in the blast furnace that extracts Iron from iron oxide is given by;Fe₂O₃ + 3CO → 2Fe + 3CO₂
We can first determine moles of Iron oxide;Moles = Mass ÷ Molar mass
Molar mass of Fe₂O₃ = 159.69 g/mol
Therefore;
Moles of Fe₂O₃ = 100 g ÷ 159.69 g/mol
= 0.626 moles
Then we determine moles of Iron producedFrom the equation;
1 mole of Fe₂O₃ reacts to produce 2 moles of Fe
Therefore;
Moles of Fe = Moles of Fe₂O₃ × 2
= 0.626 moles × 2
= 1.252 moles
Maximum theoretical mass of Iron that can be obtainedMass = Moles × molar mass
Molar mass of Fe = 55.845 g/mol
Therefore;
Mass of Fe = 1.252 moles × 55.845 g/mol
= 69.918 g
Therefore, the maximum theoretical mass of Iron metal obtained is 69.918 g
Final answer:
The maximum theoretical mass of iron from 100g of iron oxide can be calculated using stoichiometry, converted to moles, applied ratios from the chemical reaction, and then converted back to grams to get the iron mass.
Explanation:
The maximum theoretical mass of iron that can be made from 100g of iron oxide can be calculated using stoichiometry based on the balanced chemical equation for the reduction of iron oxide with carbon:
2Fe2O3 + 3C → 4Fe + 3CO2
To perform this calculation, you need the molar masses of iron (Fe) and iron oxide (Fe2O3). One mole of iron oxide has a mass of approximately 159.69 g/mol, and one mole of iron has a mass of approximately 55.85 g/mol. Using the equation:
Apply the stoichiometry to calculate the moles of Fe that can be produced.
Convert the moles of Fe back to grams to get the mass of iron.
The stoichiometry shows that from one mole of Fe2O3, you get two moles of iron. Therefore, from 100 g of iron oxide, you can theoretically produce:
100g Fe2O3
------------- x 2 mol Fe x 55.85 g/mol Fe
159.69 g/mol Fe2O3
This will give the maximum theoretical mass of iron that can be produced from 100g of iron oxide. Keep in mind that the actual yield may be lower due to practical losses and inefficiencies in the reaction process in the blast furnace.
Identify each section of the periodic table.
metals
nonmetals
metalloids
Answer:
i added this table for some help
Explanation:
here are some examples
metals:They are hard and shiny, strong, and easy to shape. They are used for many industrial purposes. This group includes iron, gold, silver, chromium, nickel, and copper, some of which are also noble metals.
non-metals:a chemical element (as boron, carbon, or nitrogen) that lacks the characteristics of a metal and that is able to form anions, acidic oxides, acids, and stable compounds with hydrogen.
metalloids:Physical properties are usually those that can be observed using our senses such as color, luster, freezing point, boiling point, melting point, density, hardness and odor. Metalloids have mixed properties which are difficult to characterize.
The sections of the periodic table are
Metals - are present at the center of the periodic table.
Non-metals - They are present on the right side of the periodic table.
Metalloids - They are present on the left side of the periodic table.
What are metals?Metals are the elements which are present in the center of the periodic table. Metals are malleable, soft, and ductile, and they're used for causing many other matters.
Metals - They serve a variety of industrial functions. Iron, gold, silver, chromium, nickel, copper, and several other metals in this category are also noble metals.
Non-metals - Chemical elements that lack the properties of metals but may nevertheless produce anions, acidic oxides, acids, and stable compounds with hydrogen are referred to as non-metals. Examples include boron, carbon, and nitrogen.
Metalloids: Visually perceptible characteristics such as color, luster, melting temperature, freezing point, hardness, density, and odor are considered physical characteristics. Metalloids have complex features that make them challenging to categorize.
Thus, the position of metals, non-metal, and metalloids are given s the picture below.
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What are the empirical formula and empirical formula mass for C10H30O10?
Empirical formula:
Empirical formula mass:
es
g/mol
Answer:
Empirical formula: CH₃O
Empirical formula mass = 31 g/mol
Explanation:
Data Given:
Molecular Formula = C₁₀H₃₀O₁₀
Empirical Formula = ?
Empirical Formula mass =
Solution
Empirical Formula:
Empirical formula is the simplest ration of atoms in the molecule but not all numbers of atoms in a compound.
So,
The ratio of the molecular formula should be divided by whole number to get the simplest ratio of molecule
As
C₁₀H₃₀O₁₀ Consist of 10 Carbon (C) atoms, 30 Hydrogen (H) atoms, and 10 Oxygen (O) atoms.
Now
Look at the ratio of these three atoms in the compound
C : H : O
10 : 30 : 10
Divide the ratio by two to get simplest ratio
C : H : O
10/10 : 30/10 : 10/10
1 : 3 : 1
So for the empirical formula the simplest ratio of carbon to hydrogen to oxygen is 1:3:1
So the empirical formula will be
Empirical formula of C₁₀H₃₀O₁₀ = CH₃O
Now
To find the empirical formula mass in g/mol
Formula mass:
Formula mass is the total sum of the atomic masses of all the atoms present in a formula unit.
**Note:
if we represent the molar mass of the empirical formula for one mol in grams then it is written as g/mol
So,
As the empirical formula of C₁₀H₃₀O₁₀ is CH₃O
Then Its empirical formula mass will be
CH₃O
Atomic Mass of C = 12
Atomic Mass of H = 3
Atomic Mass of O = 16
Total Molar mass of CH₃O
CH₃O = 12 + 3(1) + 16
CH₃O = 12 + 3 + 16
CH₃O = 31 g/mol
The empirical formula for C10H30O10 is C5H15O5 with an empirical formula mass of 151.15 g/mol.
Empirical formula: The empirical formula for C10H30O10 is C5H15O5.
Empirical formula mass: The empirical formula mass can be calculated by summing the atomic masses of the elements in the empirical formula: C = 12.01 g/mol, H = 1.008 g/mol, O = 16.00 g/mol. Therefore, the empirical formula mass is (5*12.01) + (15*1.008) + (5*16.00) = 151.15 g/mol.
which of the following correctly compares the phosphorus isotopes 31p and 32p
A. 31p has 16 protons whereas 32p has 17 protons
B. 31p has 31 protons whereas 32p has 32 protons
C. 31p has 31 neutrons whereas 32p has 32 neutrons
D. 31p has 16 neutrons whereas 32p has 17 neutrons
APEX
Answer:
The correct annswer is D)31p has 16 neutrons whereas 32p has 17 neutrons
Explanation:
An isotope is an atom of an element with the same atomic number (Z) but a different mass number (A). That is, one isotope differs from another by the number of neutrons
Z = number of protons
A = number of protons + number of neutrons.
For the phosphorus example (P), whose Z = 15:
31P -> A = 31 = number of protons + number of neutrons
Z = 15 = number of protons
A = 31 = number of protons + number of neutrons ->
31 = 15 + number of neutrons -> number of neutrons = 31-15 = 16
In the case of 32P:
A = 32 = number of protons + number of neutrons
32 = 15 + number of neutrons -> number of neutrons = 32-15 = 17
Answer:
D) 31p has 16 neutrons whereas 32p has 17
Explanation:
Apex Gang
If you are given an ideal gas with pressure (P) = 259,392.00 Pa and temperature (T) = 2.00 oC
of 1 mole Argon gas in a volume of 8.8 dm3
, calculate R to the correct number of significant
figures and units under given condition.
Answer:
R=0·083 J/mol·K
Explanation:
Ideal gas equation is
P×V = n×R×Twhere,
P is the pressure of the gas
V is the volume of the gas
n is the number of moles of the gas
R is ideal gas constant
T is the temperature of the gas in Kelvin
In case of given problem
Temperature of the gas = 273+2·00=275·00K
P=259,392·00×[tex]10^{-5}[/tex] atm
(259,392·00×[tex]10^{-5}[/tex] )×8·8 = 1×R×275·00
∴R=0·0830 J/mol·K
But according to the rules of significant figures the value of R must be with least precision of all the values of the other parameters from which the value of R is calculated
Here the least precision is in the volume as it contains only 2 significant digits
∴ Value of R must contain 2 significant digits
∴ R=0·083 J/mol·K
what other means of qualitative analysis are used to identify metals(At least five)
Metals are identified using precipitation, visible-evidenced redox reactions, and complexation reactions.
Various tests, such as the spark test, flame test, chip test, fracture test, file test, hammer test, and plain observation, can be used to identify metals.
How do scientists identify unknown metals?Chemists use the same principle to identify unknown metals using a flame test. During a flame test, chemists expose an unknown metal to a flame. The flame will change color depending on which metal is present in the substance. The scientists will then be able to identify their unknown substance.Because you are discussing qualitative analysis in this case, several techniques such as precipitation, visible-evidenced redox reactions, and complexation reactions are appropriate for identifying metals. Such reactions are sufficient if, depending on the metal's cation, the precipitate, redox behavior, and complexation produce a specific color that allows the metal to be identified.To learn more about : Metals
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Qualitative analysis of metals involves various methods such as flame tests, colorimetry, and chelation titration to identify metals.
Explanation:Qualitative analysis: In addition to precipitatiokn, other means of qualitative analysis used to identify metals include flame tests, colorimetry, and chelation titration. Flame tests involve heating a sample of the metal and observing the characteristic color of the flame. Colorimetry uses the absorption or transmission of light by the metal ions to determine their concentration. Chelation titration involves the formation of a complex between the metal ion and a chelating agent, which can be detected using indicators or spectrophotometry.
An atom has an electron configuration of
1s², 2s², 2p⁶, 3s², 3p3
how many valence electrons does the atom have?
Answer:
5
Explanation:
The full electronic configuration of the element is
1s²2s²2p63s²3p³
The total number of electrons = addition of the index
That is number of electrons = 2+2+6+2+3 = 15
Therefore the atomic number of the element is 15.
Name of element with atomic number 15 is Phosphorus with symbol P
Number of electrons in the atom of the element is 15.
Using KLMN configuration = 2:8:5
Therefore number of valence electrons is 5
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The atom has 5 valence electrons.
Explanation:The electron configuration provided indicates the arrangement of electrons in the atom's energy levels and sublevels. The last two energy levels are 3s and 3p. In this case, the 3s2 represents the filled s sublevel, and 3p3 represents the partially filled p sublevel. The valence electrons are those in the outermost energy level, so the atom in question has 5 valence electrons.
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What is the ground state electron configuration of a neutral atom of titanium
The ground state electron configuration of a neutral atom of titanium (atomic number 22) is represented as 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d², where electrons are filling up the energy levels and sublevels in sequence from lowest to highest according to the Aufbau Principle.
Explanation:The ground state electron configuration of a neutral atom of titanium, which is a transition metal with an atomic number of 22, can be determined using the principle that electrons fill the lowest energy levels first. This principle is expressed in the Aufbau Principle.
Commonly, we start with hydrogen, which has the electron configuration of 1s¹. We progress with the filling of each electron in succeeding energy levels and sublevels until we get to the number of electrons equal to the atomic number of titanium, which is 22.
In this case, the ground state electron configuration of titanium will be as follows: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d².
This means that the innermost shell (n=1) has 2 electrons in the 's' sublevel, the next shell (n=2) has 2 electrons in the 's' sublevel and 6 in the 'p' sublevel, and so on.
Crucially, you can note that the last shell in the configuration is the third shell where we find 'd' electrons. The fourth shell fills with 's' electrons, and then the 'd' sublevel in the third shell begins to fill - this is a special feature of transition metals.
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A 2.5 L sample of gases at STP (standard temperature and pressure is 273 k and 1.00 atm). When the temperature is raised to 273degrees Celsius and the pressure remains constant the new volume of the gas will be?
Answer:
x = 5.9
Explanation:
Using Charles' Law, the new volume of a 2.5 L sample of gas at STP when the temperature is raised to 273°C (546 K), keeping pressure constant, is found to be 5.0 L.
The subject of this question is Chemistry, specifically related to gases and their behavior under different conditions of temperature and pressure. The question is asking for the new volume of a gas when its temperature is raised from the standard temperature and pressure (STP), which is 0°C or 273 K and 1.00 atm, to 273°C, given that the pressure remains constant.
To solve this, we use the Charles' Law, which states that, assuming the amount of gas remains the same and the pressure is constant, the volume of the gas is directly proportional to its temperature in Kelvins. Mathematically, Charles' Law is expressed as:
V1/T1 = V2/T2
Here, V1 is the original volume, T1 is the original temperature, V2 is the new volume, and T2 is the new temperature. Substituting in the given values:
V1 = 2.5 L (original volume)
T1 = 273 K (original temperature in Kelvins, which is the same as 0°C)
T2 = 273°C + 273 = 546 K (we convert the new temperature to Kelvins by adding 273)
The pressure remains constant, so the only variable that changes is temperature. To find the new volume (V2), the equation is rearranged to solve for V2:
V2 = (V1 \\times T2) / T1
After calculating, we get:
V2 = (2.5 L \\times 546 K) / 273 K
V2 = 5.0 L
Thus, when the temperature of the gas is increased to 273°C at constant pressure, the new volume of the gas will be 5.0 liters.
The chemical equation below shows the formation of aluminum oxide (Al2O3) from aluminum (Al) and oxygen (O2).
4Al + 3O2 ----> 2Al2O3
The molar mass of O2 is 32.0 g/mol. What mass, in grams, of O2 must react to form 3.80 mol of Al2O3?
60.8
81.1
122
182
Answer:
D. 182
Explanation:
right on e2020
Answer:
182 grams of oxygen gas must react to form 3.80 mol of aluminum oxide.
Explanation:
[tex]4Al + 3O_2\rightarrow 2Al_2O_3[/tex]
Moles of aluminum oxide = 3.80 mole
According to reaction, 2 moles of aluminum oxide is obtained from 3 moles of oxygen gas.
Then 3.80 moles of aluminum oxide will be obtained from:
[tex]\frac{3}{2}\times 3.80 mol=5.7 mol[/tex] of oxygen gas.
Mass of 3.80 moles of oxygen = 5.7 mol × 32 g/mol = 182.4 g ≈ 182 g
182 grams of oxygen gas must react to form 3.80 mol of aluminum oxide.
A(n)_____________________ can either amplify an electronic signal or switch a current on and off.
Transistors
A(n) transistor can either amplify an electronic signal or switch a current on and off.
Explanation:
The main component of a transistor is a semiconductor. A transistor has at least three terminals. Voltage application through a pair of terminals affects the voltage of the other terminal. In addition, the controlling voltage can be lower than the controlled voltage, hence the amplification (gain) property of transistors. This same principle can be applied to switch on and off larger currents. If a controlling current surpasses a particular saturation point –specific to that transistor-, then it switches on the larger currents (controlled currents).
Transistors have much application in the world from being significant components in the electric circuits for speakers, hearing aids, calculators, computers, and most other digital gadgets.
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What is the pressure of 0.540 mol of an ideal gas at 35,5 L and 223 K?
Use PV = nRT and R= 8.314 okPa
molok
0.715 kPa
2.45 kPa
28.2 kPa
62.7 kPa
Mark this and return
Answer:
P = 28.2 Kpa
Explanation:
Given data:
Volume = 35.5 L
Temperature = 223 K
Number of moles = 0.540 mol
R = 8.314 Kpa. L/mol.K
Pressure = ?
Solution:
PV = nRT
P = nRT / V
P = 0.540 mol . 8.314 Kpa. L/mol.K .223 K / 35.5 L
P = 1001.2 Kpa . L /35.5 L
P = 28.2 Kpa
Answer:c
Explanation:
Please help :) thank youuu
Answer:
i believe its A
Explanation:
How many moles of KCIO3 most decompose to form 13.0 moles of potassium chloride?
Answer:
13 moles of KClO₃ will decompose to gives 13 moles of KCl.
Explanation:
Given data:
Moles of potassium chloride = 13.0 mol
Moles of KClO₃ = ?
Solution:
Chemical equation:
2KClO₃ → 2KCl + 3O₂
Now we will compare the moles of KCl with KClO₃.
KCl : KClO₃
2 : 2
13 : 13
So 13 moles of KClO₃ will decompose to gives 13 moles of KCl.
Temperature change affects the rate of a chemical reaction by changing the __________ of the colliding particle.
A) charge
B) concentration
C) size
D) speed
Answer:
D) speed
Explanation:
Reaction rates can be affected by several factors, including concentration, temperature, surface area and presence of a catalyst. Increasing concentration increases the number of effective collisions. Increasing temperature increases the kinetic energy of the particles, leading to more effective collisions
Answer:
D
Explanation:
Speed