If there are 245 grams on one side of the reaction, there must be on the other side *

245 grams

If there are 245 grams on one side of the reaction, there must be 245 grams on the other side

Explanation:

The law of conservation of mass explains that chemical reactions proceed without any loss of mass or energy as reactants are converted to products.

Hence, if the total amount in mass of reactants at the beginning of a reaction is 245 grams at the end of the reaction to the mass of products will also be 245 grams

For instance if A + B ---> C

The total mass of A and B (reactants) must be equal to the mass of C.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.