What feature of a chemical equation is used to balance the equation and make sure it obeys the law of conservation of mass?

a
numbers
b
coefficient
c
superscript
d
subscript

b.  Coefficient.

Explanation:

For example:

Zinc combines with oxygen to form zinc oxlde :

We have Zn and O2 forming ZnO:

2Zn + O2 = 2ZnO

The 2's before the Zn and ZnO balance the equation

they begin to vibrate harder causing the material that was solid to turn into a liquid i.e gallium or ice

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6