1. Patterns & the periodic table
Atoms, Subatomic Particles, Diagrams …

2. Learning goals
We are learning patterns and arrangements of the periodic table.
We are learning to draw Bohr and Lewis dot diagrams.

3. The periodic table
ELEMENT: a pure substance that cannot be broken down.

4. organization

5. organization

6. organization Groups: The vertical columns of a periodic table.
These are elements with similar properties.
Identifies number of electrons in outer shell  valence electrons
Periods: The horizontal rows of a periodic table.
Identifies the number of shells in the atom

7. The groups Alkali Metals (Group I): Soft highly reactive metals.
Alkaline Earth Metals (Group II): light, reactive metals
Halogens (Group XVII): One of the most reactive groups on periodic table.
Noble / Inert Gases (Group XVIII): Very stable, rarely react with other chemicals.

8. The atom The smallest building block of matter.
Contains three sub-atomic particles:
Proton (p+): Positively charged, inside the nucleus.
Neutron (no): No charge, inside the nucleus.
Electron (e-): Negatively charged, in shells around the nucleus.
In neutral atoms, #protons = #electrons

9. Do you remember??? element name atomic number element symbol
atomic mass

10. Whoa!!! Atomic Number = Protons = Electrons
Neutrons = Atomic Mass – Protons
Isotope – same elements with different numbers of neutrons
thus have a different mass
C-12 and C-14 (number indicate the mass)

11. With your elbow partner
Find the element symbol, atomic mass, atomic number, protons, electrons, and neutrons for the following elements:
Magnesium
Hydrogen
Chlorine

12. Bohr diagrams Draw the nucleus
Write the number of protons and neutrons in the nucleus
Draw first ring (max 2 electrons in this ring)
Add electrons
Draw second ring (max 8 electrons in this ring)
Draw third ring if needed (max 8 electrons in this ring)

13. Your turn…
With your elbow partner, draw Bohr diagrams for the following:
Lithium
Nitrogen
Helium

14. Lewis diagrams Shows valence electrons only
Draw element symbol and add valence electrons starting at 12 o’clock
With your elbow partner, draw Lewis diagrams for following elements:
Phosphorous
Neon
Chlorine
Aluminum

15. Learning goals
We are learning patterns and arrangements of the periodic table.
We are learning to draw Bohr and Lewis dot diagrams.

16. Please complete
P187 #1, 3, 4, 5, 7, 8