Unit 3 Review (8th) SY24-25

Front

What is pH?

Back

pH is a scale used to measure the acidity or alkalinity of a solution, ranging from 0 (very acidic) to 14 (very basic), with 7 being neutral.

Front

Which pH value indicates a stronger acid?

Back

A lower pH value indicates a stronger acid. For example, a solution with a pH of 1 is stronger than one with a pH of 7.

Front

What is a physical change?

Back

A physical change is a change in which the substance's physical properties are altered, but its chemical composition remains the same.

Front

Give an example of a physical change.

Back

Breaking a cracker into pieces is a physical change because the molecules are separated but it remains the same substance.

Front

What is a heterogeneous mixture?

Back

A heterogeneous mixture is a mixture in which the components are not uniformly distributed and can be easily distinguished.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new chemical substances.

Front

Give an example of a chemical change.

Back

Baking cake batter in an oven is a chemical change because it transforms the ingredients into a new substance.

Front

What factors can affect the melting point of a mixture?

Back

The melting point of a mixture can be affected by the amount and type of components in the mixture.

Front

What is a homogenous mixture?

Back

A homogenous mixture is a mixture in which the components are evenly distributed and cannot be easily distinguished.

Front

What is the difference between a physical and chemical change?

Back

A physical change alters the form of a substance without changing its chemical composition, while a chemical change results in the formation of new substances.