Answer:
When a rock gets hot it expands a little, and when it gets cold the rock contracts a little. If a rock is heated and cooled many times, cracks form and pieces of rock fall away. This type of physical weathering happens a lot in deserts, because it is very hot during the day but very cold at night.
Explanation:
Answer:
The particles of rock are rearranged.
The sizes and shapes of the rocks are changed.
The identities and total mass of the rocks remain the same.
A physical change is a change in some of the physical properties of matter, but not its identity.
Explanation:2020
WFH 8th Gr PhySci_20-21
C2H2 + 2H2 → C2H6
How many moles of hydrogen are needed to produce 13.78 mol of ethane?
Answer:
27.56 moles
Explanation:
Answer:
27.56 mol ans C)
Explanation:
1. For each of the molecules below, determine the electron geometry, molecule geometry, and bond
angles.
a. CC14 (4 Cl atoms, no lone pairs on C)
b. PF3 (3 Fatoms, 1 lone pair on P)
c. OF2 (2 F atoms, 2 lone pairs on O)
d. 13. (2 1 atoms and 3 lone pairs on central I)
e. A molecule has 2 double bonds on the central atom and no lone pairs. Predict the molecule geometry. What do you think the bond angles would be?
Answer:
CCl4- tetrahedral bond angle 109°
PF3 - trigonal pyramidal bond angles less than 109°
OF2- Bent with bond angle much less than 109°
I3 - linear with bond angles = 180°
A molecule with two double bonds and no lone pairs - linear molecule with bond angle =180°
Explanation:
Valence shell electron-pair repulsion theory (VSEPR theory) helps us to predict the molecular shape, including bond angles around a central atom, of a molecule by examination of the number of bonds and lone electron pairs in its Lewis structure. The VSEPR model assumes that electron pairs in the valence shell of a central atom will adopt an arrangement which tends to minimize repulsions between these electron pairs by maximizing the distance between them. The electrons in the valence shell of a central atom are either bonding pairs of electrons, located primarily between bonded atoms, or lone pairs. The electrostatic repulsion of these electrons is reduced when the various regions of high electron density assume positions as far apart from each other as possible.
Lone pairs and multiple bonds are known to cause more repulsion than single bonds and bond pairs. Hence the presence of lone pairs or multiple bonds tend to distort the molecular geometry geometry away from that predicted on the basis of VSEPR theory. For instance CCl4 is tetrahedral with no lone pair and four regions of electron density around the central atom. This is the expected geometry. However OF2 also has four regions of electron density but has a bent structure. The molecule has four regions of electron density but two of them are lone pairs causing more repulsion. Hence the observed bond angle is less than 109°.
Balance the equation Rb + Au2O3
Answer : The balanced chemical reaction will be:
[tex]6Rb+Au_2O_3\rightarrow 2Au+3Rb_2O[/tex]
Explanation :
As per question, when rubidium react with gold oxide then it gives rubidium oxide and gold.
This reaction is a single replacement reaction in which more reactive element displaces the least react element from its solution.
The balanced chemical reaction will be:
[tex]6Rb+Au_2O_3\rightarrow 2Au+3Rb_2O[/tex]
Step 3: Measure the Reaction Rate at 40°C
Using tongs, place the 250 ml beaker on the hotplate.
Temperature of the water:
°C. Reaction time:
seconds DONE
Answer:
Temperature of water is 40
Reaction Time is 26.3
Explanation:
Hope this helps
A reaction's rate can be used as a valuable diagnostic tool. The temperature of water is 40° C, and the rate of reaction is 26.3.
What is rate of reaction ?The speed at which a chemical reaction occurs is known as the reaction rate or rate of reaction. It is proportional to the rise in product concentration per unit time and the fall in reactant concentration per unit time. Reaction times might differ significantly.
We may devise strategies to increase production by learning how quickly things are created and what slows down reactions. This knowledge is necessary for the industrial production of various chemicals, such as fertilizers, medications, and home cleaners.
The change in a reactant or product's concentration over time is what is referred to as the rate of a chemical reaction. Concentration is measured in moles per liter, or molar, and time is measured in seconds. Therefore, we use molar per second to indicate the pace of a chemical reaction.
Thus, the temperature of water is 40° C, and the rate of reaction is 26.3.
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Natural gas is a relatively clean burning fuel, meaning it produces less _________ than oil or coal.
Answer:
Burning natural gas
Explanation:
hope this helps mark me as brainliest pls :)
Natural gas is a relatively clean burning fuel, meaning it produces less burning than oil or coal.
What is natural gas ?Methane makes up the majority of natural gas, which is a combination of gaseous hydrocarbons that also contains minor quantities of other higher alkanes. Typically, trace gases including helium, nitrogen, hydrogen sulfide, and carbon dioxide are also present in low concentrations.
When burning natural gas for energy, less carbon dioxide ( CO₂ ) and almost all other air pollutants are released into the atmosphere than when burning coal or petroleum products to provide the same amount of energy.
One of the cleanest and safest fuels is natural gas. In comparison to other fossil fuels, it produces less pollution. When natural gas is consumed, it mostly emits water vapor and carbon dioxide, which are also gases that people exhale.
Thus, Natural gas is a relatively clean burning fuel, meaning it produces less burning than oil or coal.
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Which best describes the formation of metamorphic rock?
They are formed through the cooling and hardening of magma or
lava, both below Earth's surface or on Earth's surface as volcanic
rocks.
They are formed by deposited sediment, usually at the bottom of
lakes and oceans, that is compressed over time into solid layers of
rock
They are formed as extreme weather elements, like tornadoes and
floods, break down mountains and other rock landforms into smaller
pieces.
They can be formed from any of the three rock types, withstanding
high temperatures and pressures, and forming new minerals without
melting.
D)
Answer:
D)They can be formed from any of the three rock types, withstanding
high temperatures and pressures, and forming new minerals without
melting.
Explanation:
The metamorphic rocks are formed through cooling and hardening of magma or lava, both below Earth's surface or on Earth's surface as volcanic rocks. Thus the correct option is A.
What is metamorphic rock?The type of rock which are generated when rocks are subjected to many physical changes such as heat, pressure and different chemical reactivity over a long period of time are called metamorphic rocks.
The process of metamorphism makes the rocks as chemically modified and recrystallized. This process does not melt the rocks, but it transforms the rocks into dense and compact rocks.
The common metamorphic rocks are marble, schist, phyllite, etc. The action of pressure and temperature can even change the metamorphosed rocks into new types. They can be even folded and squished.
The term meta means change and morph means form. This rocks are formed as a result of geological process such as magma intrusions.
Thus the correct option is A.
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Which of the following is NOT one of the information
chemicals stored in DNA?
a. adenino
b. guanine
c. cytosing
d. sulfide
Answer: Option B) sulfide
Explanation:
DNA is the main genetic material found in living organisms, and helps in the transmission of traits from parents to offspring through the genes.
It consists of several repeating units of polydeoxynucleotides composed of chemical like nitrogenous bases (such as thymine, cytosine, adenine and guanine), deoxyribose sugar and phosphate groups.
Thus, sulfide are not present in DNA
Balance the nuclear reaction equation for the beta minus decay of nickel-63 by completing the missing numbers.
The superscript of nickel is
.
The subscript of copper is
.
Answer: 63 & 29
Explanation:
Answer:
The superscript of nickel is
63
The subscript of copper is
29
Explanation:
A sample of gas at STP has a volume of 5.23 L. If the gas volume is changed to 3.45 L at 293 K, calculate the new pressure of the gas.
Answer: P=1.63atm
Explanation:
Stp means standard temperature and pressure
Standard temperature =273k
Standard pressure =1atm
Using the formula
P1V1/T1=P2V2/T2
P1= 1atm
V1=5.23L
T1=273k
P2=?
V2=3.45L
T2=293k
Substitute the values
1×5.23/273=p2×3.45/293
Cross multiply
293×1×5.23=p2×3.45×273
1532.39=941.85p2
P2=1532.39/941.85
P2=1.627
P2=1.63atm
Determine the oxidation STATE of S in LiSO4
Answer:
Element: S O
Oxidation number: +6 -2
Explanation:
0.5 moles of any gas is at STP, it will occupy how many LITERS of volume?
Answer: 500L
Explanation:
No of moles= volume× molarity/1000
No of moles =0.5moles
Volume=?
Molarity of a gas at stp = 1M
Stp means standard temperature and pressure
No of moles = volume ×molarity/1000
Substitute the values
0.5=volume×1/1000
Cross multiply
Volume = 1000×0.5
Volume = 500L
The volume is 500L
What is transition metals oxidation state?
can someone answer this
Answer:
Explanation:
10 N right
50 + 25 pts 75 for right answer
Some physical properties of matter include:
density
color
reactivity
luster
abundance
taste
source
Answer:
soe are appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity, and many other
Explanation:
A student needed to make 100.0 mL of 0.20M NaOH solution. How many grams of sodium hydroxide does the student need to weigh out
Answer:
0.08 g
Explanation:
100.0 mL = 0.10 L
Multiply the volume by the molarity to find moles.
0.10 L × 0.20 M = 0.002 mol
Convert moles to grams.
0.002 mol × 40 g/mol = 0.08 g
Final answer:
To prepare 100.0 mL of 0.20M NaOH solution, a student needs to weigh out 0.80 grams of NaOH, using the molar mass of NaOH and the desired solution volume and concentration.
Explanation:
Calculating the Mass of NaOH Needed for 0.20M Solution
To determine the mass of sodium hydroxide (NaOH) necessary to prepare a 100.0 mL of 0.20M NaOH solution, we have to follow multiple steps:
Calculate the number of moles of NaOH required using the formula Molarity (M) = Moles of solute (mol) / Volume of solution in liters (L).
Convert the volume from mL to L, since the molarity formula requires volume in liters.
Use the molar mass of NaOH to convert moles to grams.
First, we calculate the moles needed:
0.20 mol/L * 0.100 L = 0.020 mol NaOH
Next, we determine the mass of NaOH using its molar mass:
Molar mass of NaOH = 40.00 g/mol
Mass of NaOH = Moles * Molar mass
Mass of NaOH = 0.020 mol * 40.00 g/mol = 0.80 g NaOH
Therefore, the student would need to weigh out 0.80 grams of NaOH to prepare a 100.0 mL of 0.20M NaOH solution.
How many valence electrons does Bromine have?
Answer:
7
Explanation:
Answer:
Bromine has 7 valence electrons.
Explanation:
Bromine is in group 7 or 17, so it has 7 valence electrons use the Lewis structure for more help.
Ten gallons of water is a measurement of its mass. True False
Answer:
True
Explanation:
Its used to measure mass. Ten gallons weigh 8 pounds.
:D
Have a good day flopper :D
*eliza*
Answer:
false
Explanation:
weight and mass are very different your weight can change but your mass cannot so if you add 10 there isnt a difference in the mass
Which of these is a problem with using nuclear energy?
A.
It is very expensive to use.
B.
It is a non-renewable energy source.
C.
There aren't enough qualified technicians.
D.
We don't have a way to contain the radioactive waste produced.
Answer:
D
We don't have a way to contain the radioactive waste produced.
Explanation
Nuclear waste is non disposable and takes millions of years to biodegrade and lose it radio activeness
A beach towel is laying on the sand in the sun. Why does the sand feel hotter
to touch than the towel?
O
A. The sand is at a higher temperature.
O
O
B. The sand has a temperature far above absolute zero.
O
C. The sand has a higher latent heat of fusion.
O
D. The sand has a higher conductivity.
O
D. The sand has a higher conductivity.
Option D is the correct choice. The sand feels hotter than the beach towel due to its higher thermal conductivity, which keeps heat near the surface.
The reason the sand feels hotter to touch than the beach towel is due to its higher thermal conductivity. This concept in Physics explains that materials with higher conductivity transfer heat more efficiently. In this case, the sand absorbs heat from the sun and retains it at the surface, making it feel hot when touched.
Let's break down the options given in the question:
The sand is at a higher temperature: While this is true, it doesn't completely explain why the sand feels hotter.The sand has a temperature far above absolute zero: This is not relevant to the question since both the sand and the towel are above absolute zero.The sand has a higher latent heat of fusion: This property relates to how a material changes state from solid to liquid, which is not applicable in this context.The sand has a higher conductivity: This is the correct answer. Sand's low thermal conductivity means the heat absorbed stays near the surface, whereas materials like the towel distribute the heat more evenly.Hence, the sand feels hotter to the touch than the towel because of its higher thermal conductivity, which keeps the surface warmer.
Which substance contains bonds that involve a transfer of electrons from one atom to another
How many moles are in 56.7 L of CO2
Answer: 1,270.08L
Explanation:
-, How many food Calories (Kcal) are in 3500 joules
Answer:
3500 Calorie
Explanation:
Why did Thomson’s results from experimenting with cathode rays cause a big change in scientific thought about atoms?
A.His results gave people a picture of what atoms look like for the first time.
B.His results gave the first clues that atoms could be created and destroyed.
C.His results gave the first experimental evidence that matter is made up of atoms.
D.His results gave the first evidence that atoms were made up of smaller particles.
Answer:
D, because he discovered electrons
Explanation:
His results gave the first evidence that atoms were made up of smaller particles.
In terms of bond energies of the chemicals involved, why can hydrogen can be used as a fuel?
Answer:
see below
Explanation:
Hydrogen reacting with oxygen to generate water produces a relatively large amount of thermal energy. As requested and in terms of bonding energies, a Hydrogen - Oxygen fuel cell reaction could be illustrated as follows...
H - H + 1/2(O = O) => H - O - H
ΔHb: 1mol(-436Kj/mol) 1/2mol(498 Kj/mol) 1mol(-463 Kj/mol)
= -436Kj = -249Kj = -926Kj
ΔH(Rxn) = ∑ΔH(Products) - ∑ΔH(reactants)
= [(-926kj)] - [(-436Kj) + (-249Kj)]
= (-926 + 436 + 249)Kj = -241Kj (=> which is the Standard Heat of Formation of Water => See Thermo Tables in text appendix).
This means, on reaction of Hydrogen and Oxygen, 241Kj energy is released by exothermic process. The challenge now, is to direct this 241Kj of energy into a material substance so as to generate useful outcomes (work).
Now one should understand that the source of the energy in this problem is from the hydrogen - oxygen reaction, however, there are other mechanisms and reactions that generate thermal energy. Hydrogen fuel cell is but one.
So, now what does one do with the thermal energy generated in the fuel cell reaction. That is, what application would be needing 241Kj of energy per mole water formed? Consider two needed (hypothetical) applications => 1. to boil water and the other 2. to warm a tub of bathwater.
Our physics friends tell us that the amount of thermal heat used is related to the mass of substance receiving the heat and the resulting temperature change accompanying the transfer of thermal energy by the following equation ...
q = mcΔT where q = thermal energy. m = mass, c = specific heat & ΔT = Temperature change.
Given that both applications will receive the same amount of thermal energy ( => 241Kj) the question is reduced to how much mass would be needed to heat the water to boiling for application 1 vs amount of water to moderately heat water for a bath.
Application 1 (Boiling water) => 241Kj energy would only need a small quantity of water to achieve a high enough temperature to reach boiling point where as, Application 2 (Warming bath water) => 241Kj energy would be applied to a much larger quantity of water to limit the heating effect to a moderate temperature level.
In summary, the hydrogen-oxygen fuel cell reaction produces thermal energy => the thermal energy is directed into a mass of substance that is then heated to a needed temperature level to perform a functional service. The services derived from the H/Oxy rxn are, in essence, the utility of the process as a fuel. :-)
Addendum => The Hydrogen Electrochemical fuel cell process is the same except the process is galvanic in nature but still generates the same amount of thermal energy which is translated directly into electrical energy for needed applications.
Calculate the number of atoms in 4.8 dm^3 of neon gas at rtp
No of atoms in 4.8 dm³ of neon gas is determined in the following way.
Explanation:
We have given
Neon Gas=4.8dm³
At STP
1 mole of an ideal gas occupies 22.4 L(dm³) of volume.
which means that number of molecules occupy 22.4 L of volume.
So
4.8 dm³x 1 mole/22.4 dm³ = 0.214 moles Neon
0.214 moles x 6.02x10²³ atoms/mole = 1.29x10²³ atoms of Neon
No of Atoms in 4.8dm3 neon gas =1.29x10²³ atoms of Neon
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Final answer:
To find the number of atoms in 4.8 dm³ of neon gas at rtp, we calculate the moles of neon and then multiply by Avogadro's number, resulting in approximately 1.29 x 10²³ atoms.
Explanation:
To calculate the number of atoms in 4.8 dm3 of neon gas at room temperature and pressure (rtp), we can use Avogadro's law which states that one mole of an ideal gas occupies 22.4 liters (or dm³) at rtp. Thus, to find the number of moles of neon gas, we divide the volume of the gas by the molar volume at rtp (22.4 dm3/mol).
Number of moles (n) = volume / molar volume = 4.8 dm3 / 22.4 dm³/mol = 0.214 moles
To find the number of atoms, we multiply the number of moles by Avogadro's number (6.022 x 10²³ atoms/mol).
Number of atoms = number of moles x Avogadro's number = 0.214 moles x 6.022 x 10²³atoms/mol = 1.29 x 10²³atoms
Therefore, there are approximately 1.29 x 10²³ neon atoms in 4.8 dm³ of neon gas at rtp.
What mass of nitrogen is required to react with 16 grams of oxygen?
Approximately 8.53 grams of nitrogen is required to react with 16 grams of oxygen.
Explanation:To determine the mass of nitrogen required to react with 16 grams of oxygen, we need to set up a balanced chemical equation that represents the reaction between nitrogen and oxygen. The balanced equation is:
2 N₂ + O₂ → 2 NO
From the equation, we can see that 2 moles of nitrogen react with 1 mole of oxygen to produce 2 moles of nitrogen monoxide. Using the molar masses of nitrogen and oxygen (14 g/mol and 16 g/mol, respectively), we can calculate the molar mass of nitrogen monoxide as 30 g/mol.
Since the ratio of nitrogen to oxygen in the balanced equation is 2:1, we can set up a proportion to find the mass of nitrogen needed:
(16 g O₂) / (30 g N₂O) = (x g N₂) / (1 g O₂)
Solving for x, we find that approximately 8.53 grams of nitrogen is required to react with 16 grams of oxygen.
Final answer:
To react with 16 grams of oxygen to form nitrous oxide, you need 14 grams of nitrogen based on the stoichiometric ratio from the balanced chemical equation involving nitrogen and oxygen.
Explanation:
The question is about a chemical reaction involving nitrogen and oxygen to form an oxide of nitrogen. To find out the mass of nitrogen required to react with 16 grams of oxygen, we need to refer to the balanced chemical equation. Since 16 parts by weight of oxygen can combine with 28 parts by weight of nitrogen to form nitrous oxide (N₂O), this gives us a clear stoichiometric ratio to work with.
As oxygen has a molar mass of 16 g/mol, and nitrogen has a molar mass of 14 g/mol, the reaction for producing nitrous oxide can be represented as:
2N₂ (g) + O₂ (g) → 2N₂O (g)
From this equation, 1 mole of oxygen gas (O₂), which is 32 grams (since O₂ means two oxygen atoms), reacts with 1 mole of nitrogen gas (N₂), which is 28 grams (since N₂ means two nitrogen atoms).
Thus, we can set up a simple proportion:
32 grams of O₂ react with 28 grams of N₂16 grams of O₂ will react with X grams of N₂By cross-multiplication:
32 g O₂ / 28 g N₂ = 16 g O₂ / X g N₂
32X = 16 × 28
X = (16 × 28) / 32
X = 14 grams of N₂
Therefore, 14 grams of nitrogen are required to react with 16 grams of oxygen to form nitrous oxide.
what type of energy does a saxophone player have and what energy does it turn into
How much energy would need to be input to completely boil 17.3 moles of ice starting at 0 degrees * C and going to 100°C?
(H=40.5 kJ/mol ; H = 6.0kJ / (mol) ; specific
Answer:
[tex]Q = 934.911\,kJ[/tex]
Explanation:
The energy needed to boil 17.3 moles of ice is:
[tex]Q = (17.3\,mol)\cdot \left[\left(40.5\,\frac{kJ}{mol} \right)+ \left(\frac{4.186}{1000}\,\frac{kJ}{g\cdot ^{\circ}C} \right)\cdot \left(\frac{18.015\,g }{1\,mol} \right)\cdot (100^{\circ}C-0^{\circ}C)+\left(6\,\frac{kJ}{mol}\right)\right][/tex][tex]Q = 934.911\,kJ[/tex]
Which of the following air fronts does not move?
a Occluded front
b Cold front
c Stationary front
d Warm front
2 Points
Which of these is a benefit of using cotton grocery bags?
Answer:
What are the options given?
Answer:They can be used over or 100 times without tear.
Explanation: A P E X