Chapter 3, Section 4-Elements and The Periodic Table.

2. Non-metals
They are elements that lack most of the properties of metals
Physical Properties Chemical Properties
• Have lower density. • Most of them are
• Powder, stones, reactive.
liquids, or gases. • Their atoms usually
• Poor conductors of gain or share
heat and electricity. electrons during
• 10 of 16 non-metals chemical reaction.
are gases at room • Can form covalent
temperature. compounds with other
non-metals.

3. Group 18 – The Noble gases
He
Ne
Ar
Kr
Xe
Rn

4. Group 18 – The Noble gases
Some facts…
1) All of the noble gases have
a full outer shell, so they are
very Unreactive.
2) They all have low melting and boiling points
3) They exist as single atoms rather then diatomic molecules
3) Helium is lighter than air and is used in balloons
and airships (as well as for talking in a silly voice)

5. Group 13: Boron Group
Aluminum is the most common element
from Group 13. Group 13 properties:
• group contains one metalloid and five
metals
• 3 electrons in the outer level
• reactive
• solids at room temperature

6. Group 14: Carbon Group
Group 14 properties:
• group contains one nonmetal, two
metalloids, and two metals
• 4 electrons in the outer level
• reactivity varies among the elements
• solids at room temperature
•Example: Diamonds and soft are carbon
•Example: Silicon and Germanium make
computer chips

7. Group 15: Nitrogen Group
Group 15 properties:
• group contains two nonmetals, two
metalloids, and two metals
• 5 electrons in the outer level
• reactivity varies among the elements
• solids at room temperature (except for
nitrogen, which is a gas)

8. Group 16: Oxygen Group
Group 16 properties:
• group contains three nonmetals, one
metalloids, and one metal
• 6 electrons in the outer level
• reactive
• solids at room temperature (except for
oxygen, which is a gas)
•Example: Sulfur is the most widely used
element in the chemical industry
•Example: Oxygen makes up about 20% of
the atmosphere and is needed to burn

9. Group 7 – The halogens
F
Cl
Br
I
At

10. Group 7 – The Halogens
Some facts…
reactivity
Decreasing
1) Reactivity DECREASES
as you go down the group
(This is because the electrons are further away from the
nucleus and so any extra electrons aren’t attracted as much).
2) They exist as
diatomic molecules (so
that they both have a Cl Cl
full outer shell):
3) Because of this fluorine and chlorine are gases at room
temperature and bromine is a water

11. 1) Halogen + metal:
The halogens – some reactions
+ -
Na + Cl Na Cl
Halogen + metal ionic salt
2) non-metal + halogen:
H + Cl Cl H
Halogen + non-metal covalent molecule

12. Uses of the Halogens
• Fluorine is put into water supplies to kill
harmful bacteria and to help keep teeth
healthy.
• Chlorine is used in swimming pools to kill
bacteria in the water.
• Bromine is used in pesticides. Silver
bromide is used in photography.
• Iodine is an antiseptic on cuts and grazes.

13. Metalloids
•Metalloids are the elements that border the
zigzag line. Atoms of metalloids have about
half of a complete set of electrons in their
outer energy level.
• Metalloids have some properties of metals
and some properties of nonmetals.
• Metalloids are also called semiconductors.

14. How shells fill
• The first electron shell can only hold a
maximum of 2 electrons.
• The second electron shell can hold a
maximum of 8 electrons.
• The third electron shell can also hold a
maximum of 8 electrons.
• The fourth electron shell can also hold 8
electrons.

15. Electron structure
Consider an atom of Potassium:
Nucleus
Potassium has 19 electrons.
These are arranged in shells…
The inner shell has __ electrons
The next shell has __ electrons
The next shell has __ electrons Electron structure
The next shell has the remaining __ electron = 2,8,8,1

16. First 20 Elements continued
• Hydrogen 1
• Helium 2
• Lithium 2,1
• Beryllium 2,2
• Boron 2,3
• Carbon 2,4
• Nitrogen 2,5

17. First 20 Elements continued
• Oxygen 2,6
• Fluorine 2,7
• Neon 2,8
• Sodium 2,8,1
• Magnesium 2,8,2
• Aluminum 2,8,3
• Silicon 2,8,4

18. First 20 Elements continued
• Phosphorus 2,8,5
• Sulphur 2,8,6
• Chlorine 2,8,7
• Argon 2,8,8
• Potassium 2,8,8,1
• Calcium 2,8,8,2