Chemical equations, in a way, can be seen as algebraic equations. Cl2 is a molecular structure, so, there are two Cl atoms. 3Cl2 means 3, Cl2 molecules. So, if we think of it as adding up all the atoms, we will get, 2 P atoms and 6 Cl atoms. Now to convert. The Law of the Conservation of Mass basically says you can't add or subtract atoms out of nowhere, so the number of atoms has to stay the same when it's being converted. We need to place a coefficient with PCl3. If we look at PCl3, it shows us that there are three Cl atoms and one P atom. And looking back at how many atoms there were on the left side of the equation, we just need to double the atoms of atoms so it will be equal. So, the answer is C.) 2
Atoms gain energy as a solid changes to a liquid. If atoms energy during a change of state, they are pulled together by attractive forces and become more organized.
