Teacher Notes

• This PPT was revised June 10, 2004.• This PPT is a review on the atomic

characteristics of the four main essential elements hydrogen, carbon, oxygen, and nitrogen.

• This information is for introduction/ review only, not for testing purposes.

collection of compounds forming a living

unit; smallest unit of an organismthat can be considered living

chemical combination of two ormore elements in definite proportions

smallest unit of matter that retains its chemical properties

a substance made up of only one type of atom (periodic table of

elements) bonding between atoms of 1

or more elements; smallest unit of a compound

Can a substance be both an

element and a molecule?

molecular levels of organization from smallest to

cell

atom

element

molecule

compounds

cell

NaClCO2

C6H12O6

Can a substance be both a

molecule and a compound?What is O2? O3?

e

C H N O P SCarbonHydrogenNitrogenOxygenPhosphorusSulfur

H

Carbon is an element.

What is What is carbon?carbon?

C

commonly found as graphite, diamondsatomic number (6 protons) is constantnumber of neutrons may vary (6,

7, 8) atomic mass varies atomic mass varies

e

+ C6

carbon

S

How many protons?

++

++

6 atomic numberHow many

neutrons?

+

6 atomic mass=

How many energy levels?

2

12.11

How many electrons? 6

What properties are What properties are used to position used to position carbon on the carbon on the periodic table?periodic table?# of protons = atomic number

++

++++

11 2233 44 55 666

# of energy levels

12

C

e

What is What is hydrogen?hydrogen?

Hydrogen is an element.H

the lightest the lightest elementelementmost abundant element in the most abundant element in the

universe universe makes up 90% of the universe by makes up 90% of the universe by

weight weight

a colorless gasa colorless gas

e

HG

hydrogen

11

1.007841.00784

-

How many electrons?

1

+

How many protons?

11 atomic atomic numbernumberHow many

neutrons?00 = atomic massatomic mass

How many energy levels?

1

Which properties Which properties are used to positionare used to position

hydrogen on the hydrogen on the periodic table?periodic table?

# of protons = atomic number+ # of energy levels

11 1

H

e

Oxygen (OOxygen (O22) is an essential ) is an essential element in many compounds and element in many compounds and

is used by most organisms for is used by most organisms for respiration (to get energy for respiration (to get energy for

metabolism)metabolism)

What is What is oxygen?oxygen?

Oxygen is an element.O

Ozone (OOzone (O33)-a highly active )-a highly active compound in the atmosphere compound in the atmosphere occurring in a thin,3 mm layer occurring in a thin,3 mm layer that prevents harmful UV rays that prevents harmful UV rays

from reaching the earth.from reaching the earth.

OG

oxygen

88

15.999715.9997

How many electrons?

How many neutrons?

8

88

++

+ + +++

+

How many protons?

88 atomic numberatomic number= atomic massatomic mass

-

-

-

-

- -

-

-

How many energy levels?

22

Which properties Which properties are used to positionare used to position

oxygen on the oxygen on the periodic table?periodic table?

# of protons = atomic number+

+++++++ # of energy

levels

1 23 4 5 6 7 8

12 8

O

What is What is nitrogen?nitrogen?

Nitrogen is an element. N

proteins contain proteins contain NNmost abundant element in the air most abundant element in the air

must be “fixed” before it can be must be “fixed” before it can be used used

an odorless an odorless gasgas

H

Li

Na

K

Rb

Fr

Cs

Be

Mg

Ca

Sr

Ra

Ba

Sc

Y

Ac

La

Ti

Zr

Rf

Hf

V

Nb

Ha

Ta

Cr

Mo

W

Mn

Tc

Re

Fe

Ru

Os

Ni

Pd

Pt

Co

Rh

Ir

Cu

Ag

Au

Zn

Cd

Hg

B

Al

Ga

In

Ti

C

Si

Ge

Sn

Pb

O

S

Se

Te

Po

F

Cl

Br

I

At

He

Ne

Ar

Kr

Xe

Rn

P

As

Sb

Bi

N

N

NG

nitrogen

77

14.00714.007

How many electrons?

How many neutrons?

7

77

++

+ ++ +

+

How many protons?

77 atomic atomic numbernumber= atomic atomic massmass

-

-

-

-

-

-

-

How many energy levels?

22N

Which properties Which properties are used to positionare used to position

nitrogen on the nitrogen on the periodic table?periodic table?

# of protons = atomic number+

++++++ # of energy

levels

12 7

N

N

H

Li

Na

K

Rb

Fr

Cs

Be

Mg

Ca

Sr

Ra

Ba

Sc

Y

Ac

La

Ti

Zr

Rf

Hf

V

Nb

Ha

Ta

Cr

Mo

W

Mn

Tc

Re

Fe

Ru

Os

Ni

Pd

Pt

Co

Rh

Ir

Cu

Ag

Au

Zn

Cd

Hg

B

Al

Ga

In

Ti

C

Si

Ge

Sn

Pb

O

S

Se

Te

Po

F

Cl

Br

I

At

He

Ne

Ar

Kr

Xe

Rn

P

As

Sb

Bi

N3 41 2

5 6 7

ORGANIC compounds contain a carbon-hydrogen bond (C6H12O6,

CH4)

INORGANIC compounds do not contain a carbon-hydrogen bonds

(CO2, H2O)

lipid C,O,H

carbohydrate C,O,H

proteinC,O,H,N

nucleic acids

C,O,H,N,P

water H2O

most important inorganic

compound in living things

most cellular processes take place

in water solutionsexcellent solvent

because of polarity (substances dissolve

in water)

carbon dioxide CO2