General Chemistry 2008

The science of matter and the reactions caused
when different kinds of matter interact.
What people use chemistry to do their jobs?

Anything that has mass and volume.
What are some examples of matter that can be found in this
classroom?
Does matter exist if we can’t see it?
Give an example of something that is matter but we can’t see it.
What happens to carbon dioxide (CO2)
when it mixes with water (H2O)?
Carbon dioxide + water
CO2 + H2O
These organisms and the organisms that eat them are relying on
someone who knows about chemistry to decrease the carbonic
acid pollution.
We need to know basic chemistry to better understand how
living organisms react to their environment!

The smallest unit of matter
How small is small?
1 Atom of Helium
Diameter = 50 picometers
Mass = 1.67 x 10-27 kilograms
This is a carbon
atom.
electron
neutron
proton
Atoms most common in living
organisms:
• carbon
• nitrogen
• hydrogen
• oxygen
Name:
Description:
Favorite Activity:
Name:
Description:
Favorite Activity:
Name:
Description:
Favorite Activity:
NUCLEUS: CENTER OF
THE ATOM
•PROTONS
– POSITIVELY
CHARGED PARTICLES (+)
•NEUTRONS
– PARTICLES
WITH NO CHARGE (0)
ELECTRON LEVELS
(CLOUDS): INVISIBLE
RINGS AROUND THE
NUCLEUS
•ELECTRIONS –
NEGATIVELY
CHARGED
PARTICLES (-)
1st Cloud: 2 electrons
2nd Cloud: 8 electrons
3rd Cloud: 8 electrons
Protons have a positive charge (+)
Neutrons have no charge (0)
Electrons have a negative charge (-)
For the following pairs, decide if the particles will
attract or repel.
• proton and electron: ____________________
• proton and neutron: ____________________
• proton and proton: _____________________
• electron and electron: ___________________
• neutron and neutron: ___________________
electron
neutron
proton
•The
number of protons an atom has.
•This number never changes!
•Can be found on the periodic table
•Mass
of atom is found in the nucleus
•Atomic Mass = Protons + Neutrons
If you are having trouble with the parts of the
atom, here’s how you can practice…
•Go to class website and click on Chemistry Tab
•Open/Print the Atomic Structure Practice
Worksheet
•Complete the worksheet at home or during
study hall and bring it to Mrs. Coleman to check!
1.
2.
3.
4.
Draw the Nucleus
Add protons (+) and neutrons (o) into the
nucleus
Draw at least one electron level.
Add electrons remembering the number each
level can hold; you may need to add more
electron levels
1st: 2 electrons
2nd: 8 electrons
3rd: 8 electrons
A chart of all elements known to man. Arranged in
rows and columns. In order of atomic number.

Element – a substance made of only one kind of
atom



Example: Carbon Atoms can combine to make
elemental carbon in the form of coal or diamonds.
Atomic Number – number of protons and
electrons; atomic number of an atom never
changes
Atomic Mass – number of protons + neutrons
(mass of atom is found in the nucleus)
Element
Carbon
Chlorine
Helium
Hydrogen
Lithium
Magnesium
Neon
Nitrogen
Oxygen
Phosphorous
Sodium
Sulfer
Number
of Protons
Number
of
Neutrons
Number
of
Electrons
1st Energy
Level
Electrons
2nd Energy
Level
Electrons
3rd Energy
Level
Electrons
Why do atoms bond together?
Atoms bond together to fill up their outermost
energy levels; to become stable
Stability:
An atom is stable if its outermost energy level is
filled up.
Atom
Hydrogen
Sodium
Neon
Chlorine
Oxygen
Protons
Neutrons
Electrons
1st Energy
Level
2nd Energy
Level
3rd Energy
Level
Stable?
Chemical Bond:
A force that holds two or more atoms together;
atoms bond to become stable
Valence Electrons:
The electrons in the outermost energy level only
Dot Diagram:
A diagram that shows the chemical symbol and
dots representing only valence electrons
To become stable, atoms can GAIN, LOSE, OR SHARE electrons.
COVALENT BOND:
•CHEMICAL BOND FORMED
BY A SHARING OF
ELECTRONS
•FORMED WHEN BOTH
ATOMS NEED ELECTRONS
IONIC BOND:
•CHEMICAL BOND FORMED BY
ONE ATOM LOSING ELECTRONS
AND ANOTHER ATOM GAINING
ELECTRONS

A substance made of two or more atoms
bonded together; bonded by ionic or covalent
bonds
Ion:
An atom that has gained or lost electrons; an atom
that has a positive or negative charge
Draw a Dot Diagram of the following atoms…
Helium
Hydrogen
Sodium
Oxygen
Chlorine
Sodium
Chlorine
Magnesium
Oxygen

Gains an electron?
The atom becomes more negative (negative ion)

Loses an electron?
The atom becomes more positive (positive ion)
Molecule:
Two or more atoms that are covalently bonded
(sharing electrons).
Hydrogen
Fluorine
Oxygen
Oxygen
Hydrogen
Oxygen
Hydrogen