Protons, Neutrons, Electrons
Atomic/Bohr Models
The Atom
 3 parts
 1. Protons = positive charge
 2. Neutrons = neutral charge
 3. Electrons = negative charge
Elements
 A pure substance that cannot be broken down into
other substances
Protons, Neutrons, Electrons
 All atoms we draw will have equal protons and
electrons
Protons, Neutrons, Electrons
 # of protons = look at the atomic number
 # of electrons = look at the atomic number
 # of neutrons = subtract the atomic number
from the atomic mass
Practice
Periodic Table Parts
 Periods: move from left to right across
the periodic table (7 periods)
 Groups: move from top to bottom
down the periodic table (18 groups)
The Periodic Table
Group 1
 Alkali Metals
Lithium
Metals
Very Reactive
Sodium
Potassium
Rubidium
Cesium
Francium
1 Electron in outer
level
Group 2
 Alkaline-Earth Metals
Beryllium
Metals
Magnesium
Reactive, but not
as reactive as Alkali
Metals
Calcium
Strontium
Barium
Radium
2 Electrons in outer
level
Groups 3-12
 Transition Metals
1 or 2 Electrons in
outer level
Lanthanides and Actinides
Groups 13-16 w/ Metalloids
 Boron Group 13
Reactive
Solid at Room Temperature
3 Electrons in outer
level
Groups
13-16
w/
Metalloids
 Carbon Group 14
Reactivity varies among the
elements
Solid at room temperature
4 Electrons in outer
level
Groups 13-16 w/ Metalloids
 Nitrogen Group 15
Reactivity varies among
elements
All but nitrogen are solid at
room temp
5 Electrons in outer
level
Group 13-16 w/ Metalloids
 Oxygen Group 16
Reactive
All but oxygen are solid at room
temp
6 Electrons in outer
level
Group 17
 Halogens
Very Reactive
React violently with alkali
metals to form salts
7 Electrons in outer
level
Group
18
 Noble Gases
Unreactive
Colorless, odorless gases at room
temp
8 Electrons in outer
level (2 for Helium)
What About Hydrogen?
 Hydrogen stands alone
Reactive
Colorless, odorless gas at
room temp
Explosive reaction with
oxygen
 Groups are arranged due to all members top to bottom
having similar Physical and Chemical properties.