Control

A sample that is treated like the other experimental groups except that the

independent variable is not applied to it.

VariableFactor that can be changed

in an experiment

Independent The variable that is changed

Dependent The factor being measured

Independent Variable• The variable that YOU change in the experiment

50 mL water 100 mL water 200 mL water

Dependent Variable• The variable that

responds to the independent variable

• What changes because YOU changed something

50 mL 100 mL 200 mL

Height of Plant=(affects)

Mixture • Two or more

substances put together that can be easily separated.

Solution

• A mixture of two or more substances dissolved to form one substance (difficult to separate).

Physical Property

•A characteristic that can be observed or measured

Shiny

Red

Soft

Box = 9 cm long

Density• Describes how much matter is

packed into a given space

More Dense Less Dense

Physical Change• Change in which only the physical properties

change, you still have the same substance

breaking a pencil dissolving sugar in water

Chemical Property• Describes how a substance will react

with other substances

A bike left out in the rain can rust.

Paper is flammable. (it can burn)

Chemical Change• Change in which new substances

form that have different properties from the original substances

Rusting Metal ChainBurning match produces

smoke and ash

ElementElementa pure a pure

substance substance that is made that is made entirely from entirely from one type of one type of

atom atom

•Smallest part of Smallest part of mattermatter

•Made of protons, Made of protons, neutrons, and neutrons, and electronselectrons

•Non-livingNon-living

ATOMATOM

form when two or more atoms form when two or more atoms join together chemically join together chemically

MOLECULEMOLECULE

HH

OOHH HH HH

HH22

HH22OO

COMPOUNDCOMPOUND

a molecule that contains at a molecule that contains at least two different elementsleast two different elements

All compounds are molecules but not all molecules are compounds!All compounds are molecules but not all molecules are compounds!

HH

OOHH HH HH

HH22

HH22OO

ATOMIC #ATOMIC #

the number of protons on the number of protons on the nucleusthe nucleus

ATOMIC MASS/MASS #ATOMIC MASS/MASS #

# of # of ProtonsProtons ++ # of # of

NeutronsNeutrons

SUB-ATOMIC PARTICLES

PROTONPROTON ++ INSIDEINSIDE

NUCLEUSNUCLEUS

NEUTRONNEUTRON 00 INSIDE INSIDE NUCLEUSNUCLEUS

ELECTRONELECTRON -- OUTSIDE OUTSIDE NUCLEUSNUCLEUS

FAMILY/GROUP = FAMILY/GROUP = COLUMNSCOLUMNS

•elements have elements have similar propertiessimilar properties

•the elements in a the elements in a group have the group have the same number of same number of electrons in their electrons in their outer orbitalouter orbital*some exceptions in the transition metals

PERIODS = ROWSPERIODS = ROWS

Elements Elements have the have the

same number same number of atomic of atomic

orbitals in a orbitals in a period period