The Chemistry of Life

1
The Chemistry of Life

• Section 2.1 The Nature of Matter
• Adapted from Teacher Mrs. Rolle

2
Atomic Structure
3
Atomic Structure
4
The Atom
Electron
Nucleus
Shell or Orbit
5
If all atoms are made of protons,
neutrons, electrons, why do different atoms
have different chemical properties?
6
Answer- Its dependent upon the number and the
arrangement of

• Electrons!
• Electrons are the parts of atoms that are
  affected by chemical reactions!
• Atoms of different elements have different
  numbers of electrons, protons, and neutrons!

7
Differentiating Atoms

• Atomic Number
• Number of protons in the nucleus-determines the
  type of atom
• Since atoms are electrically neutral, the number
  of protons number of electrons

• Mass Number
• Number of protons neutrons in the nucleus
• Usually very close to the atomic mass BUT its
  not the same thing!
• Protons neutrons mass

8
The Atom Hydrogen
Proton
Electron
Hydrogen has one proton, one electron and NO
neutrons
9
The Atom Helium
Proton
Electron
Neutron
Helium has two electrons, two protons and two
neutrons
10
Mass and atomic number
Particle Relative Mass Relative Charge
Proton 1 1
Neutron 1 0
Electron 0 -1
11
The Atom Helium
Proton
Electron
Neutron
Helium has two electrons, two protons and two
neutrons
12
The Atom Lithium
Electrons
Protons
Neutrons
13
The Atom Beryllium
Electrons
Protons
Neutrons
Beryllium has four electrons, four protons and
five neutrons.
14
The Atom Boron
Electrons
Protons
Neutrons
Boron has five electrons, five protons and six
neutrons.
15
The Atom Carbon
Electrons
Protons
Neutrons
Carbon has six electrons, six protons and six
neutrons.
16
The Atom Nitrogen
Electrons
Protons
Neutrons
Nitrogen has seven electrons, seven protons and
seven neutrons.
17
The Atom Oxygen
Electrons
Protons
Neutrons
Oxygen has eight electrons, eight protons and
eight neutrons.
18
The Atom Fluorine
Electrons
Protons
Neutrons
Fluorine has nine electrons, nine protons and ten
neutrons.
19
The Atom Neon
Electrons
Protons
Neutrons
Neon has ten electrons, ten protons and ten
neutrons.
20
Isotopes

• Elements of the same element that have the same
  of protons electrons BUT differing of
  neutrons.
• Ex. 126C 136C 146C

21
p e- n0
126C 6 6 12-6 6
23892U 92 92 238-92 146
3215P 15 15 32-15 17
22
Review

• Atomic of protons- determines the atom
• Atomic mass of protons neutrons
• In neutral atoms protons electrons many
  times neutrons
• To determine of neutrons
• atomic weight - of protons

23
Review
protons- 6 electrons-6 of neutrons-6
24
Review
protons- 80 electrons-80 of neutrons-120