Answer:
1. In 0.0250 moles of potassium chromate there are 0.05 moles of potassium , 0.025 moles of chromium and 0.1 moles of oxygen are present.
2. In 4.50 moles of ammonium carbonate there are 9 moles of ammonium ions and 4.5 moles of carbonate ions are present.
Explanation:
1.
Moles of potassium chromate = 0.0250 mol
Formula of potassium chromate = 
1 mole of potassium chromate has 2 moles of potassium , 1 mole of chromium and 4 moles of oxygen.
Then in 0.0250 moles of potassium chromate:
Moles of potassium will be:

Moles of chromium will be:

Moles of oxygen will be:

2.
Moles of ammonium carbonate = 4.50 mol
Formula of ammonium carbonate =
1 mole of ammonium carbonate has 2 moles of ammonium ion and 1 mole of carbonate ion.
Then in 4.50 moles of ammonium carbonate:
Moles of ammonium ion will be:

Moles of carbonate ions will be:

Answer:
Isotopes are atoms of the same element that have different numbers of neutrons but the same number of protons and electrons. The difference in the number of neutrons between the various isotopes of an element means that the various isotopes have different masses.
(if this help pls mark as brainliest :))
<span>Heat would make the molecules move faster so they would spread out therefore making air less dense.
Less dense means less packed. Heat increase the kinetic energy</span>
The answer is D, all of them have very different masses
Because if you have a liquid then you need a glass to keep it together and when it is a solid it is already together so you don't need to do anything