Chemical and Physical Changes Flashcard

Front

What are coefficients in a chemical equation?

Back

Coefficients are the numbers placed in front of the compounds in a chemical equation to indicate the number of molecules or moles of each substance involved in the reaction.

Front

What does it mean for a chemical equation to be balanced?

Back

A balanced chemical equation has the same number of atoms of each element on both sides of the equation, indicating that mass is conserved during the reaction.

Front

How can you tell if a chemical equation is not balanced?

Back

If the number of atoms of any element differs on the reactant side compared to the product side, the equation is not balanced.

Front

What is the chemical equation for the combustion of magnesium in air?

Back

2Mg(s) + O₂(g) → 2MgO(s) is the correct equation for the combustion of magnesium in air.

Front

Which formulas contain equal numbers of nitrogen atoms?

Back

Formulas I, II, and V contain equal numbers of nitrogen atoms.

Front

What is a physical change?

Back

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition.

Front

What is a chemical change?

Back

A chemical change involves a transformation that alters the chemical composition of a substance, resulting in the formation of new substances.

Front

Give an example of a physical change.

Back

Melting ice is an example of a physical change, as it changes from solid to liquid without changing its chemical structure.

Front

Give an example of a chemical change.

Back

Burning wood is an example of a chemical change, as it transforms into ash and gases, changing its chemical composition.

Front

What is the law of conservation of mass?

Back

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