COLEMAN BIOLOGYGeneral Chemistry 2011

Chemistry

The science of matter and the reactions caused when different kinds of matter interact.

What people use chemistry to do their jobs?

Matter

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.

Atom

The smallest unit of matter

electron

neutron

proton

How small is small?1 Atom of Helium

Diameter = 50 picometersMass = 1.67 x 10-27

kilograms

This is a carbon atom.

Atoms most common in living organisms:• carbon• nitrogen• hydrogen• oxygen

The Atoms Family

Name:

Description:

Favorite Activity:

Name:

Description:

Favorite Activity:

Name:

Description:

Favorite Activity:

Subatomic Particles:The parts of the atom

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 electrons2nd Cloud: 8 electrons3rd Cloud: 8 electrons

Particle Charges

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: ___________________

Atomic Structure & The Periodic Table

electron

neutron

proton

ATOMIC NUMBER•The number of protons an atom has.•This number never changes!•Can be found on the periodic table

ATOMIC MASS•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!

DRAWING ATOMS

1. Draw the Nucleus2. Add protons (+) and neutrons (o) into the

nucleus3. Draw at least one electron level. 4. Add electrons remembering the number each

level can hold; you may need to add more electron levels

1st: 2 electrons2nd: 8 electrons3rd: 8 electrons

Periodic Table of ElementsA chart of all elements known to man. Arranged in rows and columns. In order of atomic number.

Periodic Table of Elements

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 Number of Protons

Number of Neutrons

Number of Electrons

1st Energy Level Electrons

2nd Energy Level Electrons

3rd Energy Level Electrons

Carbon

Chlorine

Helium

Hydrogen

Lithium

Magnesium

Neon

Nitrogen

Oxygen

Phosphorous

Sodium

Sulfer

Atomic BondsWhy do atoms bond together?

Atoms bond together to fill up their outermost energy levels which makes

them become stable

Stability:

An atom is stable if its outermost energy level is filled up.

Atom Protons Neutrons Electrons 1st Energy Level

2nd Energy Level

3rd Energy Level

Stable?

Hydrogen

Sodium

Neon

Chlorine

Oxygen

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.

Atomic BondsCOVALENT 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

Ionic BondsIon:

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

Dot Diagrams Showing Ionic Bonding

Sodium Chlorine

Dot Diagrams Showing Ionic Bonding

Magnesium Oxygen

What happens to an atom when it…

Gains an electron?

The atom becomes more negative (negative ion)

Loses an electron?

The atom becomes more positive (positive ion)

Covalent BondsMolecule:

Two or more atoms that are covalently bonded (sharing electrons).

Dot Diagrams Showing Covalent Bonding

Hydrogen Fluorine

Dot Diagrams Showing Covalent Bonding

Oxygen Oxygen

Dot Diagrams Showing Covalent Bonding

Hydrogen Oxygen Hydrogen

Element Symbol Dot Diagram

Stable?Unstable?

Gain or Lose? How many?

Hydrogen

Helium

Lithium

Carbon

Aluminum

Sulfur

Chlorine

Argon

Chemical Bonding

1.

Li Cl

Type of Bond:

Explanation: