Periodic Table
Additional Necessary Info
Electrons arrange themselves on the lowest energy level possible
When all the electrons in an atom have the lowest possible energies, the atom is said to be in its
ground state
This means the atom is the most stable it can be---it is in its least reactive form---but some can
still react.
The Periodic Table
Originally developed by Mendeleev
Has Columns: Groups (Tell you the # of valence Electrons)
Has Rows: Periods (Tell you the number of energy levels/orbitals
Elements are arranged by increasing atomic number
Elements in the same groups share similar properties
Classes of Elements
Metals: majority of elements on the table
Good conductors, solid at room temp (Except Hg), malleable, ductile
Transition Metals: Middle, lower, don't behave like other metals
NonMetals: Right side of the table
Properties opposite of metals
low boiling points, most are gases at room temp (solids in this area are very brittle)
Metalloids: Elements that share properties of metals and nonmetals
Fall on a zigzag line from boron (5) to Astatine (85)
Alkali Metals
Group 1 on the periodic table
most reactive group of metals
increase reactivity top to bottom
have 1 valence electron
React easily with group 17
Alkaline Earth Metals
Group 2 on the periodic table
2 valence electrons
harder than alkali metals
React easily with group 16
Carbon Family
Group 14
Contains non metals, metals, and metalloids
has 4 valence electrons
elements of life
silicon is the most abundant element on earth
Nitrogen Family
Group 15 on the periodic table
5 valence electrons
contains nonmetals, metalloids, and metals
Halogens
Group 17 on the periodic table
7 valence electrons
react easily with alkali metals
highly reactive nonmmetals
All end in -ine
Noble Gases
Most stable gases on the periodic table
Have a full valence level, meaning they do not need to react to be stable
Trends
Atoms decrease in reactivity from left to right across the table
Group 1 is the most reactive Metal group
Group 17 are the most reactive nonmetals
Atoms lose metallic properties left to right
Atoms decrease in size left to right
Atoms increase in size from the top to bottom of a group
Summary
In your group, discuss and answer:
You now know about elements in the same group, and what the group number tells you about
valence electrons. What does that tell you the valence electrons determine???