Science Grade 8 Topic 5

chemical change

A change in matter that produces one or more new substances

Mixture

A combination of two or more substances that are not chemically combined

Density

A measure of how much mass is contained in a given volume.

Weight

A measure of the force of gravity on an object

substance

A single kind of matter that is pure and has a specific set of properties.

Compound

A substance made of two or more elements chemically combined in a specific ratio, or proportion.

which of the following is a solution? A) saltwater B) macaroni and cheese C) cake mix D) vegetable soup

A) saltwater

Matter

Anything that has mass and takes up space

which describes a physical change? A)a marshmallow burning over the fire B)snow melts from the rooftop C) a tree produces sugar through photosynthisis D)milk turns sour

B)snow melts from the rooftop

Atom

Basic unit of matter

Volume

The amount of space an object takes up

physical change

a change of matter from one form to another without a change in chemical properties

physical property

a characteristic that can be observed or measured without changing the identity of the substance

chemical property

a property of matter that describes a substance's ability to participate in chemical reactions

Element

a substance made of only one kind of atom

a solid transparent block of a substance has been sitting on your kitchen counter all day. what type of property will tell you whether it is a block of ice. Physical or chemical?

physical

Distillation

separation of a liquid by boiling followed by condensation

Mass

the amount of matter in an object

conservation

the principle that properties such as mass, volume, and number remain the same despite changes in the forms of objects

convert

to change from one form to another

Molecule

two or more atoms held together by chemical bonds