What are examples of the law conservation of matter?

Question

What are examples of the law conservation of matter?

Answer 1

matter cannot be created or destroyed is the law of conservation of matter. Like when you have an ice cube it melts into a liquid and when it gets heated it becomes a gas. It may dissapear to the human eye but it is still there

Answer 2

Burn something completely to ash, it appears as if matter was lost, the burnt item was destroyed, but if you collected the gases expelled and weighed them, the weight of the gas and ash produced would equal the weight of the oxygen consumed in the burning/oxidation and the weight of the original item so the matter wasn't destroyed it merely changed to a different form -- most of the solid matter became gaseous matter.

Answer 3

An example is oxidation:  If an known mass of copper is heated in the presence of oxygen, the copper will oxidise, but if you can accurately measure it the mass of the resulting copper + copper oxide will be the same as the mass of the copper plus the mass of the oxygen that bonded with it. So no mass has been lost.

Similarly if you weigh an ice cube, then allow it to melt, then the mass of the water will be the same as that of the icecube provided there has been no evaporation.

Closed metamorphic systems also obey this law - if you metamorphose a volume of rock, then even though the minerals in it may change, the actual mass of each of the elements in the system will be the same as they were at the start.