Answer:
0.123 mol
Explanation:
1 mol Na/22.99g na=0.123 mol
Answer:
[tex]\boxed {\boxed {\sf 0.261 \ mol \ B}}[/tex]
Explanation:
We are asked to find the number of moles in a sample of 2.82 grams of boron.
We convert grams to moles using the molar mass or the mass of 1 mole of a substance. These values are found on the Periodic Table. They are equivalent to the atomic masses, but the units are grams per mole instead of atomic mass units.
Look up the molar mass of boron (B).
B: 10.81 g/molConvert using dimensional analysis. Set up a conversion factor using the molar mass.
[tex]\frac {10.81 \ g \ B}{ 1 \ mol \ B}[/tex]
We are converting 2.82 grams of boron to moles, so we multiply by this value.
[tex]2.82 \ g \ B *\frac {10.81 \ g \ B}{ 1 \ mol \ B}[/tex]
Flip the ratio so the units of grams of boron cancel.
[tex]2.82 \ g \ B *\frac { 1 \ mol \ B}{10.81 \ g \ B}[/tex]
[tex]2.82*\frac { 1 \ mol \ B}{10.81}[/tex]
[tex]\frac {2.82}{10.81} \ mol \ B[/tex]
[tex]0.2608695652 \ mol \ B[/tex]
The original value of grams has 3 significant figures, so our answer must have the same. For the number we found, this is the thousandth place. The 8 in the ten-thousandth place tells us to round the 0 up to a 1.
[tex]0.261 \ mol \ B[/tex]
There are approximately 0.261 moles of boron (B)in 2.82 grams of boron.
Why do you think dark surfaces absorb radiation better than light surfaces?
Your answer→ The lighter side absorbs less of the incident light, reflecting some of the energy. Darker materials also emit radiation more readily than light-colored materials, so they cool faster.
To solve this we must be knowing each and every concept related to radiation. Therefore, dark surfaces absorb radiation better than light surfaces as dark surfaces absorbs light of all wavelengths.
What is radiation?According to the energy of the emitted particles, radiation is frequently classified as being either ionizing or non-ionizing. More than 10 eV is often carried by ionizing radiation, which is sufficient to ionize atoms as well as molecules and rupture chemical bonds.
The word refers to radiation having an energy level high enough to ionize atoms, or to remove electrons from atoms to produce ions. Whenever an electron is removed from an atom's electron shell, or, as we may say, when it is "tried to knock out," the action of ionization takes place. Dark surfaces absorb radiation better than light surfaces as dark surfaces absorbs light of all wavelengths.
Therefore, dark surfaces absorb radiation better than light surfaces as dark surfaces absorbs light of all wavelengths.
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In order for a light bulb to be turned on in a circuit, it must have what kind of switch?
Answer:
Both switches must be closed in order for the circuit to be complete and for the bulb to light. (This would indicate the 'armed' status of this burglar alarm.) Magnetic switches come in 2 varieties - "Normally Closed" and "Normally Open". These 2 terms describe the state of the switch when it is NOT being controlled by the magnet.
Explanation:
A sample of gas at 1.0°C is expanded at constant pressure from 10 L to 15 L. The final temperature is:
a: 1.50 °C
b: 411 °C
c: None of all
d:138 °C
e: 183 °C
Answer:
y
Explanation:
yea Mami you know like for real I feel you you know iam seeing but tomorrow I see the equation for the last works positive AAAAA
Scientific Notation!!!!!
#9 b) PLEASE HELP!!!
Explanation:
9) a) (9.84×10³)/(6.12×4.27×10³+⁷) = 9.84×10³/6.12×4.27×10¹⁰ = 9.84×10³-¹⁰/6.12×4.27
= 0.376×10^-7.
b) (4.36×10⁸×1.82×10³)/(0.0856×4.7×10⁶)
= (7.9352×10⁸+³)/(0.40232×10⁶)
= 19.72×10⁸+³-⁶ = 19.72×10⁵
hope this helps you.
5. A student measures the mass of an object three times on a balance in order to calculate the objects
density. The recorded masses are 70.21 g, 64.55 g, and 74.70 g. The accepted value for the mass of
the object is 70.21 g.
a. Are these measurements accurate? Why or why not?
b. Are the measurements precise? Why or why not?
Answer:
This is not chemistry this is physics
C3h8+o2=co2+h2o balance the equation
Using the provided table and the equation below, determine the heat of formation (in kJ/mol) for CuBr₂.
CuCl₂ (s) + Br₂(l) → CuBr₂ (s) + Cl₂ (g) ∆H° = 64.1 kJ/mol
CuCl2= -205.9 kJ/mol
Br2= 0 kJ/mol
Cl2= 0 kJ/mol
The heat of formation of CuBr₂ (s) = -141.8 kJ/mol
The heat of reaction ΔH = ∑ΔHproducts - ∑ΔHreactants
ΔH = ΔHCuBr₂ (s) + ΔHCl₂ (g) - [ΔHCuCl₂ (s) + ΔHBr₂(l)]
where ΔHCuBr₂ (s) = heat of formation of CuBr₂ (s), ΔHCl₂ (g) = heat of formation of Cl₂ (g) = 0 kJ/mol, ΔHCuCl₂ (s) = heat of formation of CuCl₂ (s) = -205.9 kJ/mol, ΔHBr₂(l) = heat of formation of Br₂(l) = 0 kJ/mol and ΔH = heat of reaction = 64.1 kJ/mol
Substituting the values of the variables into the equation, we have
ΔH = ΔHCuBr₂ (s) + ΔHCl₂ (g) - [ΔHCuCl₂ (s) + ΔHBr₂(l)]
64.1 kJ/mol = ΔHCuBr₂ (s) + 0 kJ/mol - [-205.9 kJ/mol + 0 kJ/mol]
64.1 kJ/mol = ΔHCuBr₂ (s) + 0 kJ/mol + 205.9 kJ/mol - 0 kJ/mol
64.1 kJ/mol = ΔHCuBr₂ (s) + 205.9 kJ/mol
ΔHCuBr₂ (s) = 64.1 kJ/mol - 205.9 kJ/mol
ΔHCuBr₂ (s) = -141.8 kJ/mol
So, the heat of formation of CuBr₂ (s) = -141.8 kJ/mol
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What is condensation
When the Northern Hemisphere is tilted ________the Sun, the sunlight is _________ direct than it is in the Southern Hemisphere. (Select all that apply.)
away from; less
toward; more
toward; less
away from; more
toward, more
away from, less
Explanation:
When the northern hemisphere is tilted toward the sun, the sunlight is more direct than it is in the southern hemisphere. This explains why it's wintertime in Australia while at the same time, it's summertime in the US.
When the northern hemisphere is tilted away from the sun, the sunlight is less direct than it is in the southern hemisphere. This explains why it's summertime in Australia while it's wintertime in the US.
In the following reaction, how many liters of oxygen will react with 270 liters of ethene (C2H4) at STP?
C2H4(g) + 3O2(g) 2CO2(g) + 2H2O(g)
The volume of one mole of gas at STP is 22.4 liters.
A car is accelerated at a rate of 2.5 meters/second?. If the starting speed is 5.0 meters/second, how
many seconds will it take the car to reach a final speed of 27.0 meters/second?
Answer:
8.8 seconds
Explanation:
Formula: acceleration = (v - u) /t where v = final velocity, u = initial velocity and t = time
a = 2.5 m/s²
u = 5.0
v = 27. 0
t =?
at = v - u
t = (v - u) /a
= (27- 5)/ 2.5
= 8.8 s
6. What is the atomic mass of Hafnium if out of every 200 atoms, 10 have mass 176.00 g/mol, 38 have mass
177.00 g/mol, 54 have mass 178.00 g/mol, 28 have mass 179.00 g/mol, and 70 have mass 180.00 g/mol?
Answer:
ttyhjj
Explanation:
Name the following compound and tell what type of compound it is: Protons 6, Neutrons 8, and electrons 6
Answer:
Carbon-14
Explanation:
It's carbon, because the element has 6 proton.
It's not an ion, because there are same number of proton and electron 6=6
It is carbon-14 because 6 proton + 8 neutron = 14
The electronic transition in a hydrogen atom from n = 7 to n = 2 emits electromagnetic radiation having a longer wavelength than a transition from n = 6 to n = 3.
Answer: I'll leave the answer rounded to three sig figs.
mark me brainlist
So, you can say that in a hydrogen atom, an electron located on
n
i
=
2
that absorbs a photon of energy
4.85
⋅
10
−
19
J
can make the jump to
n
f
=
6
.
Explanation:
The question wants you to determine the energy that the incoming photon must have in order to allow the electron that absorbs it to jump from
n
i
=
2
to
n
f
=
6
.
A good starting point here will be to calculate the energy of the photon emitted when the electron falls from
n
i
=
6
to
n
f
=
2
by using the Rydberg equation.
How many moles are present in a sample of HCI with a mass of with a mass of 3.65g?
Answer:
number of moles = 0.1001 mol
Explanation:
number of moles = mass/molar mass
number of moles = 3.65g / 36.459 g/mol
n = 0.1001 mol
The ___ of a bottle tells you how much liquid it can hold. what is the anewer
Answer:
Volume
Explanation:
Volume is how much of a substance something can hold!
Hope this helped, have a nice day! :)
The word that completes the sentence is "volume."The volume of a bottle refers to how much liquid it can hold, typically measured in liters or milliliters.
Knowing the volume of a bottle is important when you need to measure out or store a certain amount of liquid. Different types of bottles have different capacities, so it's important to check the label or specifications to determine the right size for your needs.
Volume is a measure of three-dimensional space. It is often quantified numerically using SI derived units or by various imperial or US customary units (such as the gallon, quart, cubic inch). The definition of length (cubed) is interrelated with volume. The volume of a container is generally understood to be the capacity of the container; i.e., the amount of fluid (gas or liquid) that the container could hold, rather than the amount of space the container itself displaces.
Thus, the word that completes the sentence is "volume."
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Please help XD answer all of these questions to get 70 pnts!
Answer:
1 Density- degree of consistency measured by the quantity of mass per unit volume.
2 Cubic centimeters
3 Volume- Volume is the amount of space occupied by a substance, while mass is the amount of matter it contains. The amount of mass per unit of volume is a sample's density.
4 Liters
5 Mass- Scientific Definition of Mass Mass is the quantity of inertia (resistance to acceleration) possessed by an object or the proportion between force and acceleration referred to in Newton's Second Law of Motion (force equals mass times acceleration). In other words, the more mass an object has, the more force it takes to get it moving.
Explanation:
Answer:
What is density? The measure of how much matter is in a certain volume.
Which one of these are not a unit of volume? Answer: m² is not a unit of volume.
What is Volume? The length of an object.
Which of these is not a unit of mass? Metric ton (t)
What is mass?A measure of the amount of matter in an object or substance.
The RDI for sodium for adults is 2300mg. What amount of table salt (in grams) contains this quantity of sodium? Express answer to two significant figures and include the appropriate units.
Answer:
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50 Points (Brainliest too)! Please help!
1. In detail, explain what transmutation is.
2. In one to two sentences, explain what an alpha particle is.
3. Explain the difference between a chemical equation and a nuclear equation.
4. What is the relationship between the atomic number and the mass number of a 5. nucleus?
Please help me understand these!! I'm really confused!
Answer:
Transmutation is the conversion of an atom of one element into an atom of a different element through nuclear changes.
An alpha particle is a particle composed of 2 protons and 3 neutrons. It results from transmutation because of the change in protons in a large nucleus.
A chemical equation is balanced accord to the number of atoms of each element before and after the change. This is also shows the Law of Conservation of Matter.
A nuclear equation is balanced according to mass number and charge (atomic number). These equations can’t be balanced like chemical equations because the identities of the atoms can change. On the left of equation, the top number is the atomic mass and the bottom number is the atomic number. Take note that if you add the atomic mass (top number), you’ll get the the atomic mass of of the atom pre-transmutation. Same applies with atomic number. This shows a balanced nuclear equation.
The atomic number is the number of protons in a nucleus. The mass number is the sum of the protons and neutrons in a nucleus. Electrons have very small masses, so they are not accounted in atomic mass.
The Lewis electron-dot structure of oxygen has how many dots?
Answer:
Oxygen has 6 valence electrons and follows the octet rule.
If you were drawing a lewis structure for O2, there would be a total of 12 valence electrons (6 x 2 = 12).
The completed structure would have a double bond between the two oxygen atoms with 2 lone pairs per oxygen, giving you a total of 8 electrons that are lone pairs (or dots).
Colligative properties are dependent only on the number of particles in a solution, and not their identity. (select all that apply) Select one or more: a. Acidity b. Depression of freezing point c. Lowering of vapor pressure d. Osmotic pressure e. Elevation of boiling point f. Mortality g. Value h. Molarity
These colligative properties include reduced vapor pressure, increased boiling point, decreased freezing point, and increased osmotic pressure.
What do you mean by osmotic pressure?When a semipermeable membrane separates a solution from pure water, osmotic pressure is defined as the pressure that must be applied to the solution side to stop fluid movement.These colligative properties include reduced vapor pressure, increased boiling point, decreased freezing point, and increased osmotic pressure. As described in this module, this small set of properties is critical to many natural phenomena and technological applications.The pressure required to prevent water from diffusing through a membrane via osmosis is known as osmotic pressure. The concentration of the solute determines it. Water diffuses from the lower concentration area to the higher concentration area.Osmotic pressure is a 'colligative' property, like freezing point depression, which means that it depends on the number of particles in solution but not on their chemical identity.To learn more about : Osmotic pressure
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If a aluminum cube had a mass of 20g and the length of each side was 2cm between what to liquids would it float?
Answer:
density=20/8 g/cc=2.5 g/cc
Mercury is more dense, so aluminum will float on it. Water is less dense, so the aluminum will be below water.
Aluminum will float atop mercury because it is more dense than it. Due to water's lower density, the metal will lie below the surface.
What is density?Density is defined as the measure of how densely a material is packed together.
It can also be defined as the mass of a solid substance per unit volume.
Density is important because it enables us to predict which compounds will float and which will sink in a liquid, density is a crucial notion. As long as an object's density is lower than the liquid's density, it will often float.
The term "density" refers to the relationship between a substance's mass and the volume it takes up in space. The mass, size, and arrangement of an object's atoms influence its density.
Density can be expressed as
Density = mass / volume
There are two types of density.
Absolute densityRelative densityThus, aluminum will float atop mercury because it is more dense than it. Due to water's lower density, the metal will lie below the surface.
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An atom contains three protons, two neutrons, and one electron. What is the charge of the nucleus?
A: 3+
B: 5+
C: 2+
D: 0
Answer:
A.3+
Explanation:
️️️️️️️️️️️️️️
You and your family have just arrived in Water Cycle Land. You are going on a new ride called the Water Cycle. You sit in your seat and the ride begins. All of a sudden something goes wrong. Your body is turning into a water droplet! Think about what you have learned about the water cycle. Now tell a story about what happens to you as you travel through the water cycle. By the way, how do you get your body back to normal?
Answer: you dont drink water for years
Explanation: dont drink water for years on end
Are the atoms really "sharing" electrons? Explain.
Answer:
yes, in certain cases
there are different types of bondings between atoms
and in some they lend electrons to make their atom stable this type of bonding is called ionic bonding
and in covalent bond the atoms share their electrons
Ribosome factory part or worker
How many unpaired electrons does fluorine have in its ground state electron configuration?
Answer:
1 unpaired electron (s)
Explanation:
How many atoms are in 1.27 mol of pure aluminum?
Answer:
To determine the amount of atoms (or molecules) present given the moles of an element, you multiply the amount of moles by Avogadro's number,
6.022
⋅
10
23
4 mol
A
l
6.022
⋅
10
23
1
m
o
l
=
2.41
⋅
10
24
atoms/molecules of
A
l
Explanation:
Acetylene (C2H2) gas and oxygen (02) gas react to form carbon dioxide (CO2) gas and water (H20) vapor. Suppose you have 2.0 mol of C,H, and 1.0 mol
of o, in a reactor
Calculate the largest amount of CO, that could be produced. Round your answer to the nearest 0.1 mol.
The largest amount of CO₂ produced when 2 moles of C₂H₂ reacted with 1 mole of O₂ is 0.8 mole
We'll begin by writing the balanced equation for the reaction. This is given below:
2C₂H₂ + 5O₂ —> 4CO₂ + 2H₂O
2 : 5
2 : 1
From the balanced equation above,
We can see that O₂ is the limiting reactant as lesser amount of it is available.
Finally, we shall determine the largest amount of CO₂ produced by using the limiting reactant as illustrated below:
From the balanced equation above,
5 moles of O₂ reacted to produce 4 moles of CO₂.
Therefore,
1 mole of O₂ will react to produce = 4/5 = 0.8 mole of CO₂.
Thus, the largest amount of CO₂ produced from the reaction is 0.8 mole
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Time's Up!
Submit
Balance the following chemical equation (if necessary):
Rb(s) + RbNO3(s) → Rb2O(s) + N2(g)
3C,
2-
Reset
OS
< >
1
3
4
2.
5
07
6
7
8.
9
o
Answer:
im sorry but what is it post to be
Explanation: