Flashcardizz S4 T9 L1 & 2 Chemical Change & Conservation of Mass

Front

What is a chemical change?

Back

A process where a new substance is formed with different properties than the original substance.

Front

What is the conservation of mass?

Back

The principle stating that mass is neither created nor destroyed in a chemical reaction; the total mass of reactants equals the total mass of products.

Front

How many atoms of hydrogen are in one molecule of water (H2O)?

Back

2 hydrogen atoms.

Front

What is the chemical formula for three molecules of water?

Back

3H2O.

Front

What happens to the atoms during a chemical change?

Back

Atoms are rearranged and bonded in new ways to form a new substance.

Front

What is the difference between a chemical change and a physical change?

Back

A chemical change results in the formation of new substances, while a physical change does not change the substance's chemical identity.

Front

What is an example of a chemical change?

Back

Burning wood, which produces ash, smoke, and gases.

Front

What is an example of a physical change?

Back

Melting ice, which changes from solid to liquid but remains water.

Front

What does it mean if a reaction is exothermic?

Back

It releases energy, usually in the form of heat.

Front

What does it mean if a reaction is endothermic?

Back

It absorbs energy from its surroundings.