The average kinetic energy of a collection of gas particles depends on the temperature of the gas and nothing else.
Answer:

Explanation:
<u>Convert Atoms to Moles</u>
The first step is to convert atoms to moles. 1 mole of every substance has the same number of particles: 6.022 ×10²³ or Avogadro's Number. The type of particle can be different, in this case it is atoms of silver. Let's create a ratio using this information.

We are trying to find the mass of 8.23 ×10²³ silver atoms, so we multiply by that number.

Flip the ratio so the atoms of silver cancel. The ratio is equivalent, but places the other value with units "atoms Ag" in the denominator.


Condense into one fraction.


<u>Convert Moles to Grams</u>
The next step is to convert the moles to grams. This uses the molar mass, which is equivalent to the atomic mass on the Periodic Table, but the units are grams per mole.
Let's make another ratio using this information.

Multiply by the number of moles we calculated.

The moles of silver cancel out.



<u>Round</u>
The original measurement of atoms has 3 significant figures, so our answer must have the same. For the number we calculated, that is the ones place.
The 4 in the tenths place tells us to leave the 7 in the ones place.

8.23 ×10²³ silver atoms are equal to approximately <u>147 grams.</u>
Answer:
The correct option is c) exothermic, negative.
Explanation:
Reactions that releases heat to the surroundings are called exothermic, and are characterized by negative entalpy (ΔH) values.
B is correct. Molecules move faster when they are hotter because they have more energy. You can notice this change with your naked eye. Molecules in solids don't move. They have barely any energy. Hope this helps! ;)
Answer: crystalline solid
Explanation: Most ionic compounds exist in crystalline solid form especially at room temperature.