6 Elements that are needed for living things ____________

____________ = 96% of the Human Body

Atoms = ________________________ ________________________ = has all the

characteristics of that element

= ________________________ ________________________

NUCLEUS

PROTONS positive (p+)

Neutrons neutral (n°)

e-e-

e-

e-

e-

e-

e-

e-

e-

Electron cloud

ELECTRONS negative (e-)

All nuclei are _________ because of the ________.

Each Each elementelement has a different number of _________

NUCLEUS e-

e-

Energy Levels

e-

e-

e-

e-

e-e-

e-e-

NUCLEUS e-

e-

Energy Levels

e-

e-e-

e-e-

e-

Example: Oxygen = 8 e-

O

Atomic Number

8

15.9994

The # of p+ in nucleus

Determines which element an atom is

= the total # of particles an atom

Atomic Weight

O

Atomic Number

8

15.9994

Atomic Weight

then if you ROUNDYou will get the…

Mass Number

= the sum of p+ and n°

MASS NUMBER

Number of p+

Number of n°

Number of Neutrons = Mass # - Atomic #

O8

15.9994

So, why is this a

decimal?It is an average of all the isotopes!

What’s an isotope?

The Nuclei of 3 isotopes of H+

PROTIUM DEUTERIUMTRITIUM

1 PROTON

1 PROTON

1 NEUTRON

1 PROTON

2 NEUTRONS

Atoms that have the same # of p+ but different # of n°

Example of Compounds:•Water•Carbon Dioxide•NaCl•C6H12O6•HCl•NH4

Substance with atoms of 2 or more elements that are chemically combined

Compounds =

Atoms come together when the result is more ________ than the individual atoms

NUCLEUS e-

e-

e-

e-

e-

e-

e-e-

e-e-

If filled to capacity then it is STABLE

How do they fill energy levels?

1) BY SHARING ELECTRONS

2) BY GAINING OR LOSING ELECTRONS

Method One: sharing electronsExample: Hydrogen

e-e-

e-

Examples of Molecules with Covalent Bonding: sugars, fats, proteins, & water

MOLECULE = group or atoms held together by a covalent bond

Examples of Molecules with Covalent Bonding: sugars, fats, proteins, & water

Method Two: gaining or losing electrons

An atom (or group of atoms) that gains or loses electrons = IONION = (charged particle)

If I lose a negative electron then I will become more positive

If I gain an electron then I will become more negative

11 e-

11 p+

17 e-

17 p+

ionic

bond

Ionic bond = attractive force between 2 ions of opposite charge

MIXTURE Combination of

substances in which the individual components retrain their own properties

Can be separated Ex: chex mix

SOLUTION Mixture in which 1

or more substances (solutes) are distributed evenly in another substance (solvent)

Ex: Jello