Chapter 3: The Periodic Table

(This is the best of what I could fit. I suggest to use your own periodic table instead :P)

• -Main-group elements- Groups I to 0
• -Alkali Metals- Group I
• -Halogens- Group VII (non-metals)
• -Noble gases- Group 0 (very unreactive)
• -Transition elements- The block of elements between Group II and III
• -The broadest distinction in the table is metals and non-metals. Non-metals are on the right of the thick line while the metals on the left side of the thick line.
• -A metal is an element that does conduct electricity, is malleable and ductile.
• -A non-metal is an element that doesn't conduct electricity and isn't malleable or ductile.
• -A metalloid is an element that have some features of a metal and some features of a non-metal.
• The difference between Metals and non-metals.

Metals	Non-Metals
They are usually solids at rtp except mercury which is liquid at rtp. They have high mp and bp usually	They are usually solids or gases at rtp except bromine which is a liquid at rtp. They have low mp and bp often.
They are usually hard and have high density	Non-metals are softer than metals usually. They have low densities usually.
All metals are good conductors of electricity.	Poor conductors of electricity
Malleable and ductile	Brittle
Grey in colour except gold and sliver, can be polished	Vary in colour, dull (when solid)
Sonorous	Not sonorous

Trends in the Periodic Table

• -Elements in the same group (vertical columns of elements) have the similar chemical properties and physical properties.
• -Elements in the same group have the same number of electrons in their outershell.
• -For main-group elements, the number of the group is the number of electrons in the outershell. For e.g chlorine is in Group VII so it has 7 electrons in its outershell.
• -The period (rows of elements) number tell us the number of shells in the element. Hydrogen in period 1 has 1 shell for e.g.
• -The atomic size of an atom increases down the group (as the number of shells increase) but decreases across a group since the number of electrons in the last orbit increases hence increasing the attractive force between electrons and protons (-ve and +ve) decreasing the size of the atom as a result.
• -Elements become more metallic (ability to lose electrons) down a group and less metallic across a period since the electrons in the last orbit increases so gaining electrons is much easier than losing them all.
• -In metal groups (like group I and group II) the reactivity of the elements increases as you go down the group.
• The most reactive metal is Caesium since Francium is radioactive (metals in Group I in more reactive than the metals in Group II)
• In the group of non-metals, the reactivity of the non-metals increase up the group
• The most reactive non-metal is Fluorine in Group VII.