Chem - Unit 1

Mass

The amount of matter in an object

Qualitative

characteristics excluding numbers

Quantitative

characteristics using numbers

Accuracy

How close a measurement is to the true or accepted value

Precision

How close measurements of the same item are to each other

Sig Figs

a measurement that consists of accurate digits and one estimated digit.

Compound

uniform & fixed composition; multiple types of atoms

Element

uniform & fixed composition; one type of atom

Solution

uniform & non-fixed composition; also called a homogeneous mixture

Mixture (heterogeneous)

variable & non-fixed composition

Pure substances

elements and compounds

What type of substances can be separated by physical means?

mixtures

What is a solution?

a homogeneous mixture

Physical change

change in shape, size, state of matter, etc.

Chemical change

a change that results in a change in chemical composition

What type of change produces a new substance?

Chemical change

What type of change can be reversed by physical means?

Physical change

Which state of matter has the greatest amount of molecular motion?

gas

Which state of matter has the least amount of molecular motion?

solid

Intensive property

a property that could not change with a change in the amount of a substance you have

Extensive property

a property that changes with the amount of substance you have

Distillation

separating chemicals by boiling

Decantation

removing a liquid layer from the top of a solid layer