PTE & Conservation of Mass

Front

What is the law of conservation of mass?

Back

The mass of the reactants equals the mass of the products.

Front

Which are the reactants in the reaction 2Mg + O2 ---> 2MgO?

Back

Mg and O.

Front

What is a chemical reaction?

Back

A process in which atoms rearrange to form new substances.

Front

What is Helium's atomic number?

Back

2.

Front

What happens to the mass of wood when a log is burned?

Back

The mass stays the same, but becomes smoke and ash.

Front

Define reactants in a chemical reaction.

Back

Substances that undergo change during a chemical reaction.

Front

What are products in a chemical reaction?

Back

Substances formed as a result of a chemical reaction.

Front

What is an example of a physical change?

Back

Melting ice.

Front

What is an example of a chemical change?

Back

Rusting of iron.

Front

What does it mean for a reaction to be balanced?

Back

The number of atoms for each element is the same on both sides of the equation.