Answer:
The main difference between the two models was about the location of the electron in an atom.
Explanation:
Rutherford described that:
The electrons were outside of the nucleus.They were equal in number to the "positiveness" of the nucleus.Also, He randomly placed the negative electrons outside the nucleus.Bohr improved the Rutherford model:
Bohr placed the electrons in distinct energy levels.Electrons only exist in fixed orbitals (shells) and not anywhere in between.Each shell has a fixed energyRutherford explained the nucleus of an atom, while Bohr was more into the electrons and their energy levels.Exact Answer:
In the Rutherford model, electrons can exist in any location outside the nucleus.
In the Bohr model, electrons can exist only in certain energy levels surrounding the atom.
b. What is the standard potential for the cell? (2 points)
Answer:
Explanation:a cells state potential of the cell is the standard state conditions 1 mole per liter (1 m) and pressure of atmospheric 25oC
Which of the following is a chemical property of a base?
A) slippery feel
B) conducts an electric current
C) turns red litmus paper blue
D) forms hydronium ions in water
Answer:
D) forms hydronium ions in water
Explanation:
Texture and conductivity are physical properties which makes answer A and B wrong. Answer C does not refer to a chemical reaction.
if molar mass of Na2SO4xnH2O is 304.04 mol/g, what is the hydration number of n
Answer:
n = 9
Explanation:
Given parameters:
Molar mass of Na₂SO₄.nH₂O = 304.04gmol⁻¹
Solution
To find the hydration number n, we simply express atomic masses of the atoms in the compound as equal to the given molar mass.
Atomic mass of Na = 23g
S = 32g
O = 16g
H = 1g
Molar mass of the compound is evaluated as:
2(23) + 32 + 4(16) + n[2(1) + 16] = 304.04
46 + 32 + 64 + 18n = 304.04
142 + 18n = 304.04
18n = 304.04 - 142
18n = 162.04
n = 9
What contribution did Niels Bohr make to atomic theory?
A. He performed an experiment that determined the charge of the
electron
B. He made a model of the atom called the plum-pudding model.
C. He discovered that the photoelectric effect was caused by light
shining on metal
D. He made a model of the atom, with electrons circling the nucleus.
Answer: D
Explanation:
Just took the test
Final answer:
Niels Bohr's contribution to atomic theory was his proposal of the Bohr's Model, which introduced the concept of electron orbits and explained the atomic spectrum of hydrogen.
Explanation:
Niels Bohr made significant contributions to atomic theory by proposing a model of the atom in 1913 called the Bohr's Model. This model incorporated Rutherford's planetary model and explained the atomic spectrum of hydrogen. Bohr's model was based on the concept that electrons move around the nucleus in circular orbits at certain allowed radii, and it introduced quantum mechanics principles. However, it is important to note that Bohr's model has been superseded by more accurate and complex models in modern atomic theory.
Total these measurements. Your answer should indicate the proper accuracy.
Your answer should indicate the proper precision (correct number of significant figures).
8.32 cm
8.00 cm
8.30 cm
8.3 cm
Answer:
Total of all numbers added with the correct rounding and number of significant figures
Explanation:
1. Add up all the numbers
8.32+8.00+8.30+8.3
2. Determine how many significant figures should be in your final answer. When it comes to addition, it will be the fewest number of decimal places. since 8.3 has one decimal place, your final answer should only have one decimal place.
3. Round your final answer to the nearest tenths
Give the numbers that we have to add up.
A mixture of three noble gases has a total pressure of 1.25 atm. The individual pressures exerted by neon and argon are 0.68
atm and 0.35 atm, respectively. What is the partial pressure of the third gas, helium?
Use Py-P+P 2+P3 + +P
O 0.22 am
O 0.33 atm
O 1.03 atm
O 228 atm
Answer:
0.22 atm
Explanation:
The total pressure is the sum of the partial pressures.
P = P₁ + P₂ + P₃
1.25 atm = 0.68 atm + 0.35 atm + P
P = 0.22 atm
Answer:
0.22 atm
Explanation:
First, you need to add up each of the values of the known gases
0.68+0.35
Then you need to subtract that value from the total pressure to find the partial pressure of the third value
1.25-(0.68+0.35)
By doing that you get the answer of 0.22 atm
In the reaction below, if 5.71 g of sulfur is reacted with 10.0 g of oxygen, how many grams of sulfur trioxide will be produced?
Answer:
14.3 g SO₃
Explanation:
2S + 3O₂ → 2SO₃
First, find the limiting reactant. To do that, calculate the mass of oxygen needed to react with all the sulfur.
5.71 g S × (1 mol S / 32 g S) = 0.178 mol S
0.178 mol S × (3 mol O₂ / 2 mol S) = 0.268 mol O₂
0.268 mol O₂ × (32 g O₂ / mol O₂) = 8.57 g O₂
There are 10.0 g of O₂, so there's enough oxygen. The limiting reactant is therefore sulfur.
Use the mass of sulfur to calculate the mass of sulfur trioxide.
5.71 g S × (1 mol S / 32 g S) = 0.178 mol S
0.178 mol S × (2 mol SO₃ / 2 mol S) = 0.178 mol SO₃
0.178 mol SO₃ × (80 g SO₃ / mol SO₃) = 14.3 g SO₃
12. A large recipe calls for 250 quarts of milk. What is
this in cm3?
Answer:
236588 cm3
Explanation:
If a large recipe calls for 250 quarts of milk, there are 236588 cm3.
Multiply the volume value by 946.353
The initial activity of 37Ar is 8540 disintegrations per minute. After 10.0 days, the activity is 6990 disintegrations per minute. what is the activity after 47.2 days?
Answer:
Approximately 3318 disintegrations per minute.
Explanation:
The activity [tex]A[/tex] of a radioactive decay at time [tex]t[/tex] can be found with the following equation:
[tex]\displaystyle A(t) = A_0 \cdot \mathrm{e}^{-\lambda\cdot t}[/tex].
In this equation,
[tex]\mathrm{e}[/tex] is the natural base. [tex]\mathrm{e}\approx 2.71828[/tex].[tex]A_0[/tex] is the initial activity of the decay. For this question, [tex]A_0 = \rm 8540\; min^{-1}[/tex].The decay constant [tex]\lambda[/tex] of this sample needs to be found.The decay constant here can be found using the activity after 10 days. As long as both times are in the same unit (days in this case,) conversion will not be necessary.
[tex]A(10) = A_0\cdot \mathrm{e}^{\rm -\lambda \times 10\;day}= (\mathrm{8540\; min^{-1}})\cdot \mathrm{e}^{\rm -\lambda \times 10\;day}[/tex].
[tex]A(10) = \rm 6690\; min^{-1}[/tex].
[tex]\displaystyle \frac{\rm 6690\; min^{-1}}{\mathrm{8540\; min^{-1}}} = \mathrm{e}^{\rm -\lambda \times 10\;day}[/tex]
Apply the natural logarithm to both sides of this equation.
[tex]\displaystyle \ln{\left(\frac{\rm 6690\; min^{-1}}{\mathrm{8540\; min^{-1}}}\right)} = \ln{\left(\mathrm{e}^{\rm -\lambda \times 10\;day}\right)}[/tex].
[tex]\displaystyle \rm -\lambda \cdot (10\;day) = \ln{\left(\frac{\rm 6690\; min^{-1}}{\mathrm{8540\; min^{-1}}}\right)}[/tex].
[tex]\displaystyle \rm \lambda= \rm \frac{\displaystyle \ln{\left(\frac{\rm 6690\; min^{-1}}{\mathrm{8540\; min^{-1}}}\right)}}{-10 \; day} \approx 0.0200280\; day^{-1}[/tex].
Note that the unit of the decay constant [tex]\lambda[/tex] is [tex]\rm day^{-1}[/tex] (the reciprocal of days.) The exponent [tex]-\lambda \cdot t[/tex] should be dimensionless. In other words, the unit of [tex]t[/tex] should also be days. This observation confirms that there's no need for unit conversion as long as the two times are in the same unit.
Apply the equation for decay activity at time [tex]t[/tex] to find the decay activity after 47.2 days.
[tex]\displaystyle \begin{aligned}A(t)& = A_0 \cdot \mathrm{e}^{-\lambda\cdot t}\\&\approx \rm \left(8540\; min^{-1}\right)\cdot \mathrm{e}^{-0.0200280\; day^{-1}\times 47.2\;day}\\&\approx \rm 3318\; min^{-1}\end{aligned}[/tex].
By dimensional analysis, the unit of activity here should also be disintegrations per minute. The activity after 47.2 days will be approximately 3318 disintegrations per minute.
The atomic particles given off as a result of nuclear fusion are?
Answer:
Gamma Radiation maybe
Explanation:
The atomic particles given off as a result of nuclear fission are Beta and Alpha particles, so the only thing left is gamma radiation.
I hope this helps, and as always, I am joyous to assist anyone at any time.
What structural feature is indicated by the suffix -ene in the name of a hydrocarbon
a double bond between carbon atoms
a ring of carbon atoms
a triple bond between carbon atoms
a branched carbon chain
Answer:
A double bond between carbon atoms
Explanation:
The suffix -ene is used for alkenes, which tells you that the molecule has a carbon-carbon double bond.
Ob] The electrodes of a fuel cellare in contact with water and all
The electrodes are made of platinum rather than iron.
©
State why iron is not a suitable metal for the electrodes of the cell.
Iron is unsuitable for fuel cell electrodes due to its reactivity and corrosion, whereas platinum is favored for being inert and stable in electrochemical reactions.
Iron is not a suitable metal for the electrodes of a fuel cell because it is reactive and can undergo corrosion, especially when in contact with water, leading to the degradation of the cell's performance. Instead, platinum is often used for electrodes because it is an inert metal that does not react during redox processes. This ensures that the platinum electrodes do not appear in the overall electrochemical reaction of the cell, thus maintaining their integrity and the efficiency of the fuel cell.
a student adds 3.5 moles of solute to enough water to make a 1500mL solution. what is the concentration?
The answer is:
[tex]MolarConcentration=\frac{3.5moles}{volume(1.5L)}=2.33molar[/tex]
Why?Since there is not information about the solute but only its mass, we need to assume that we are calculating the molar concentration of a solution or molarity. So, need to use the following formula:
[tex]MolarConcentration=\frac{mass(solute)}{volume(solution)}[/tex]
Now, we know that the mass of the solute is equal 3.5 moles and the volume is equal to 1500 mL or 1.5L
Then, substituting into the equation, we have:
[tex]MolarConcentration=\frac{3.5moles}{1.5L}=2.33molar[/tex]
Have a nice day!
Hey there!:
Molarity, molar concentration, concentration in mol/L or concentration in quantity of matter is the ratio of the amount of matter of the solute (mol) by the solution volume (in liters), expressed in the Unit mol/L (molar).
Number of moles = 3.5 moles
1 L = 1000 mL
Volume in liters = 1500 mL / 1000 => 1.5 L
Therefore:
Molarity = number of moles / Volume in liters:
Molarity = 3.5 / 1.5
Molarity = 2.333 M
Hope this helps!
determines the type of element an atom is.
The number of neutrons
The number of electrons
o The number of protons
o The number of atoms
Answer: C. The number of protons
Explanation: because when you take or add protons to an element it becomes another element.
How many moles of CO2 are produced when 45.0g of C6H6 react completely in the following equation? 2C6H6+ 15O2 → 12CO2 + 6H2O
The answer is in the photo
Answer : The moles of [tex]CO_2[/tex] produced are, 3.462 moles.
Explanation : given,
Mass of [tex]C_6H_6[/tex] = 45.0 g
Molar mass of [tex]C_6H_6[/tex] = 78 g/mole
First we have to calculate the moles of [tex]C_6H_6[/tex].
[tex]\text{Moles of }C_6H_6=\frac{\text{Mass of }C_6H_6}{\text{Molar mass of }C_6H_6}=\frac{45.0g}{78g/mole}=0.577moles[/tex]
Now we have to calculate the moles of [tex]CO_2[/tex]
The given balanced chemical reaction is,
[tex]2C_6_H6+15O_2\rightarrow 12CO_2+6H_2O[/tex]
From the balanced chemical reaction, we conclude that
As, 2 moles of [tex]C_6H_6[/tex] react to give 12 moles of [tex]CO_2[/tex].
So, 0.577 moles of [tex]C_6H_6[/tex] react to give [tex]\frac{12}{2}\times 0.577=3.462[/tex] moles of [tex]CO_2[/tex].
Therefore, the moles of [tex]CO_2[/tex] produced are, 3.462 moles.
A soft drink contains 11.5% sucrose (C12H22O11) by mass. How much sucrose, in grams, is contained in 355 mL (12 oz) of the soft drink? (Assume a density of 1.04 g/mL.)
Express your answer to three significant figures and include appropriate units.
Answer:
42.5 g
Explanation:
Calculate the mass of the soft drink given the density and volume:
355 mL × 1.04 g/mL = 369.2 g
Now calculate the mass of sucrose given the percentage:
0.115 × 369.2 g = 42.46 g
Rounded to 3 significant figures, the mass is 42.5 g.
Answer:
42.458 g of sucrose is contained in 355 mL (12 oz) of the soft drink
Explanation:
Volume of the soft drink = 355mL
Density = 1.04 g/mL
We know
Density = Mass / Volume
Rearranging the formula
Mass of soft drink = Density × volume
[tex]=1.04 g/mL \times 355mL=369.2 g[/tex]
[tex]Mass = \frac {(mass of solute)}{(mass of solution )} \times 100%[/tex]
[tex]11.5 = \frac {(mass of solute (sucrose))}{(mass of solution(soft drink) )} \times 100%[/tex]
[tex]11.5 = \frac {(mass of solute (sucrose))}{(369.2 g)} \times 100%[/tex]
So
Mass of sucrose
[tex]=\frac {(11.5 \times 369.2g)}{(100)}[/tex]
= 42.458 g is the Answer
Construct a pair of conversion factors that relate moles of S to moles of Al2 (SO4)3.
Explanation:
First conversion factor: moles of SO₄ per mole of Al₂(SO₄)₃.
3 mol SO₄ / mol Al₂(SO₄)₃
Second conversion factor: moles of S per mole of SO₄.
1 mol S / mol SO₄
Altogether:
(3 mol SO₄ / mol Al₂(SO₄)₃) × (1 mol S / mol SO₄) = 3 mol S / mol Al₂(SO₄)₃
To relate moles of S to moles of Al2(SO4)3, we use the compound's 2:3 ratio to establish that 1 mole of Al2(SO4)3 has 3 moles of S. Conversion factors are 1 mole Al2(SO4)3/3 moles S and 3 moles S/1 mole Al2(SO4)3. These allow for conversions between the moles of the two substances.
Explanation:To construct a pair of conversion factors that relate moles of S to moles of Al2(SO4)3, we need to look at the chemical compound's formula. The compound aluminum sulfate, Al2(SO4)3, shows there are three sulfate (SO42-) ions for every two aluminum (Al3+) ions.
This indicates a 2:3 ratio between Al and SO4 in the compound. Each sulfate ion contains one atom of sulfur (S), so for every mole of Al2(SO4)3, there are three moles of sulfur atoms (S). Thereby, the conversion factors are:
1 mole Al2(SO4)3 / 3 moles S3 moles S / 1 mole Al2(SO4)3These factors can be used to convert moles of sulfur to moles of aluminum sulfate and vice versa.
Which of the following is an example of how chemicals make our lives easier?
Answer:
B. Chemicals can keep bread fresher longer.
Explanation:
I checked the label of my bread :)) and I found one ingredient which keep the freshness:
ascorbic acoid (vitamin C) - it has antioxidant properties
Answer:
Chemicals can keep bread fresher longer.
what is the concentration (M) of a solution with a pH of 9.52 ?
Answer:
[H⁺] = 3.02 x 10⁻¹⁰M
Explanation:
Given parameters:
pH of the solution = 9.52
Unknown:
Concentration of the solution
Solution
There is a relationship between the pH and concentration of a solution.
pH = -log₁₀[H⁺]
The unknown here is [H⁺],
Now making it the subject of the formula
[H⁺] = Inverse log₁₀(-pH)
[H⁺] = Inverse log₁₀(-9.52)
[H⁺] = 3.02 x 10⁻¹⁰M
What is the most appropriate way to present the data below?
Week
2
3
4
Plant Mass (g)
22
61
87
123
O bar graph
O chart
line graph
O pie graph
Mark this and return
Save and Exit
Next
Answer:
Its not bar graph
Explanation:
Answer:
C- Line Graph
Explanation:
Fill in the blanks to complete each statement about weathering
Weathering is the breakdown of rocks into smaller particles called
weathering is when rocks are physically broken into smaller pieces, but the minerals in
the rock remain the same.
When a rock is broken down in a way that changes the mineral composition, it is called
weathering
Answer:
Weathering is the breakdown of rocks into smaller particles called sediment (not sediments)
Mechanical weathering is when rocks are physically broken into smaller pieces, but the minerals in the rock remain the same
When a rock is broken down in a way that changes the mineral composition, it is called Chemical Weathering.
The blanks about Weathering in the question are filled as follows;
SedimentSedimentMechanical/PhysicalSedimentMechanical/PhysicalChemicalAccording to the question;
We are required to fill in the blanks to complete each statement about Weathering.For Statement 1:
Weathering is the breakdown of rocks into smaller particles called Sediment.For Statement 2;
When rocks are physically broken into smaller pieces, but the minerals inthe rock remain the same, Such kind of weathering is termed Mechanical/physical weathering.For Statement 3:
When a rock is broken down in a way that changes the mineral composition, it is called Chemical weathering.Read more;
https://brainly.com/question/19448468
Deposition is a _____ force since it involves dumping sediment in a particular location.
A. chemical
B. destructive
C. mechanical
D. constructive
Answer:
D) constructive
Explanation:
Deposition is a constructive force since it involves dumping sediment in a particular location.
Constructive is the correct answer. A deposition is a constructive force when it involves dumping into sediment a particular location. I hope this will help you. Have a wonderful day!
what is the name of an ion with a positive charge
Answer:
cation
Explanation:
Answer:
Cation
Explanation:
Cation is the name of an ion with a positive charge.
Cation is made electron loss.
Also, it means atoms forced into position or gained.
which source is most likely an authority on the subject
Answer:
Dr. Patel, a cardiologist, presents her findings on heart disease
Explanation:
(10 points) Please help asap!!
Answer:
1-3 2-2 3-1
Explanation:
What is one example of the use of an infrared sensor?
A. Information is relayed to a visually impaired individual about the location of objects.
B. Detecting the presence of humans trapped under collapsed buildings.
C. Bar code scanner tracks store inventory
D. Monitoring feed for farm animals to keep them healthy.
Answer: B. Detecting the presence of humans trapped under collapsed buildings.
Explanation: Infrared sensors are also capable of measuring the heat being emitted by an object and detecting motion. Infrared technology is found not just in industry, but also in every-day life. Televisions, for example, use an infrared detector to interpret the signals sent from a remote control.
(As) in noble-has notion
Answer:
[Ar] 4s2 3d10 4p3
Explanation:
Arsenic is Element 33. It is the 15th element in the Fourth Row, following the noble gas Ar at the end of the Third Row.
Thus, its noble gas electron configuration is
[Ar] 4s2 3d10 4p3
What is the oxidation state of cr in CrPO4 and Cr3(PO4)2?
Answer:
Explanation:
Oxidation state of Cr in CrPO₄
As a general rule, the algebraic sum of all the oxidation numbers of all atoms in a neutral compound is zero.
The compound above is in its neutral state and we sum all the oxidation numbers and equate to zero:
The oxidation number of P is -2
O is -2
Let the oxidation number of Cr be x:
x + (-2) + 4(-2) = 0
x -2-8 = 0
x -10 = 0
x = +10
For Cr in Cr₃(PO₄)₂
Using the same rule:
2(x) + 2[-2 + 4(-2)] = 0
2x + 2(-2-8) = 0
2x -20 = 0
x = +10
Answer:
[tex]CrPO_4: Cr +3\\Cr_3(PO_4)_2: Cr+2[/tex]
Explanation:
[tex]CrPO_4[/tex] and [tex]Cr_3(PO_4)_2[/tex] are compounds known as ternary salts
This means that they are formed by a metal or a non-metal and an anion
Its formula is [tex]M_x(X_yO_z)_w[/tex], that is, the cation is written first and then the anion and the simplified charges are exchanged if possible.
The anion [tex]PO_4[/tex] has a load of -3: [tex]PO_{4}^{-3}[/tex]
Let's look at the first compound [tex]CrPO_4[/tex] we observe that when exchanging the charges 3 of the[tex]PO_4[/tex] does not appear therefore the charges are simplified as the charges are completely simplified, it means that the chromium has the same valence (numerically but with opposite sign) that the anion
Therefore the oxidation state of Cr in [tex]CrPO_4[/tex] is +3
Let's look at the second compound [tex]Cr_3(PO_4)_2[/tex], it is observed that when exchanging the valences, the 3 of the [tex]PO_4[/tex] is with the chromium, and with the anion is 2
As valencia are not multiples, they cannot be simplified.
When exchanging the valences, the[tex]PO_4[/tex] has the valence corresponding to the chromium which in this case is + 2
9. Matter is anything that
Ms
O A. has mass and takes up space.
O B. is important to human society.
O C. has only one physical state
O D. contains two elements combined chemically
Mark for review (Will be highlighted on the review page)
de Previous Question
Neyt
as
Given the following balanced reaction between liquid ammonia and oxygen gas to produce nitrous oxide gas and water, how many grams of water, H2O, are produced from 317 grams of ammonia and excess oxygen? (To find the molar mass in the problem use the periodic table and round the mass to the hundreds place for calculation).
(A) 224 g
(B) 335 g
(C) 503 g
Answer:
(C) 503 g
Explanation:
Balanced reaction:
2NH₃ + 2O₂ → N₂O + 3H₂O
Stoichiometry:
317 g NH₃ × (1 mol NH₃ / 17.03 g NH₃) = 18.61 mol NH₃
18.61 mol NH₃ × (3 mol H₂O / 2 mol NH₃) = 27.92 mol H₂O
27.92 mol H₂O × (18.02 g H₂O / mol H₂O) = 503 g H₂O
Answer:
(C) 503 g of water, H2O, are produced from 317 grams of ammonia and excess oxygen
Explanation:
[tex]2 NH_3+2 O_2>N_2 O+3 H_2 O[/tex]
Molar mass of
[tex]H_2 O=(2\times1.008)+15.999=18.02 g/mol[/tex]
Molar mass of
[tex]NH_3=14.01+(3\times1.008)=17.03 g/mol[/tex]
The conversions are
Step 1:
Mass [tex]NH_3[/tex] to moles [tex]NH_3[/tex] by dividing with molar mass [tex]NH_3[/tex]
Step 2:
Moles [tex]NH_3[/tex] to moles [tex]H_2 O[/tex] by using mole ratio of [tex]NH_3:H_2 O[/tex] i.e., 2 : 3
Step 3:
Moles [tex]H_2 O[/tex] to mass [tex]H_2 O[/tex] by multiplying with molar mass [tex]H_2 O[/tex]
[tex]317gNH_3 \times \frac {(1mol NH_3)}{(17.03gNH_3 )} \times \frac {(3mol H_2 O)}{(2mol NH_3 )} \times \frac {(18.02g H_2 O)}{(1mol H_2 O)}[/tex]
[tex]= 503g H_2 O[/tex] is formed.
(Answer)
Please note :
To convert moles to mass, we multiply by molar mass
To convert mass to moles, we divide by molar mass
Molar mass is the mass of 1 mole of the substance
For example molar mass of [tex]CO_2[/tex] is
[tex](12.0+2\times16)=44 g/mol[/tex]
(we just add the atomic mass of the atoms to get the molar mass of the substance).