Atoms and the Periodic Table

1
Atoms and the Periodic Table

• L.E.Q. What is matter?

2
Atoms

• An atom is composed of ELECTRONS (negative
  charge) orbiting the outside of a nucleus.
• The nucleus is made up of PROTONS (positive
  charge) and NEUTRONS (neutral charge).
• Electrons orbit the nucleus of an atom in an
  electron cloud.

3
Electron Clouds

• Electron clouds can be broken into 7 different
  energy levels.
• Each energy level can only hold a specific number
  of electrons.
• Each energy level must be filled before a higher
  energy level can have electrons.

4
Electron Cloud
50e
18e
32e
72e
P N
8e
2e
5
Reading Information on Periodic Table
16 6A
Electron Configuration Atomic Number Symbol
Name
Memorize Atomic of protons in the
nucleus Atomic mass of protons of
neutrons of neutrons Atomic mass-atomic
number ( of protons) of protons of
electrons Electron Configuration of
electrons in outer most energy level (shell).
6 C Carbon 12.011
Average Atomic Mass
Why is the mass of carbon a decimal?
6
Practice
1 1A
What is the atomic number of Li? How may
electrons are in Li? What is the Atomic Mass? How
many neutrons are in Li? How many electrons are
in Lis outer shell? Draw a Lithium Atom
3 Li Lithium 6.941
Look at the periodic table in your notes What is
the name of an element that has 47 protons?
7
Lithium Atom

• Lithium has 3 protons and 3 electrons
• Atomic Mass is 6.941, round to the nearest whole
  number (7)
• Neutrons Atomic Mass (7)-Atomic Number (3).
  There are 4 neutrons in a Lithium Atom

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8

• Choose a few elements from the periodic table.
• Create a practice set of 10 questions similar to
  the questions on slide 8 of your notes.
• Have your partner complete the questions.
• Turn in both question sets when finished.

9
Electron Configuration

• Electrons orbit the nucleus of an atom in a
  cloud.
• Electrons do not orbit in a sphere neatly around
  the nucleus, instead they tend to migrate in
  different shapes around the nucleus.