1. Life depends on chemistry
The Nature of Matter
Life depends on chemistry

2. Atoms Atoms are the basic unit of matter.
They are the smallest piece of matter that keeps unique qualities.
Nucleus – center section of the atom
Orbitals – outer section of the atom

3. Subatomic Particles Subatomic particles are the parts of an atom.
Three types:
Proton
Neutron
Electron

4. Protons Mass = 1 atomic mass unit (AMU) Charge = Positive (+)
Location = Nucleus
The number of protons is equal to the atomic number on the periodic table.
The number of protons determine which element an atom is.

5. Electrons Mass = 1/2000 atomic mass unit (AMU) Charge = Negative (-)
Location = Orbital
The number of protons is equal to the atomic number on the periodic table.
Electrons determine the chemical properties of an atom.

6. Neutrons Mass = 1 atomic mass unit (AMU) Charge =no charge (0)
Location = Nucleus
The number of neutrons is equal to the atomic mass – the atomic number

7. Isotopes
Isotopes are atoms of the same element that have different number of neutrons.
Example One:
All carbon atoms have 6 protons
All carbon atoms have 6 electrons
Carbon atoms can have 6, 7 or 8 electrons.

8. Isotopes Example Two: All potassium atoms have 19 protons.
All potassium atoms have 19 electrons.
Potassium atoms can have 18,19,20 or 21 neutrons.

9. Compounds
A compound is a substance formed by two or more elements in a definite proportion.
H2O =Two hydrogen (H) atoms for one oxygen
(O) atom.
NaCl = One sodium (Na) atom for one chlorine
(Cl) atom.

10. Chemical Bonds Atoms in compounds are held together by chemical bonds.
Two types of chemical bonds
Ionic bonds
Covalent bonds

11. Ionic Bonds
Formed when one atom loses an electron to a different atom.

12. Covalent Bonds
Formed by atoms sharing electrons