# What happens during a chemical reaction?

##### 1 Answer
Aug 10, 2018

The formation of new substances, and the making and breaking of strong chemical bonds.

#### Explanation:

This is a specific definition, and of course most of chemistry is based on such reactions...

For the generalized reaction...

$A + B \rightarrow C + D$

...the chemical reaction CONSERVES two properties: (i) mass is conserved, i.e. the mass of the products is PRECISELY equal to the mass of the reactants; and (ii) charge is conserved, i.e. the charge of the reactants is precisely equal to the charge of the products. And so if you start with $10 \cdot g$ of reactant from all sources, AT MOST you are going to get $10 \cdot g$ of product, and in practice you are not even going to get that (why not?). And this principle of conservation of mass is why chemists and educators place such emphasis on stoichiometry:

$\text{GARBAGE IN EQUALS GARBAGE OUT...}$