periodicity

Question 1

How many elements are there

Answer 1

around 100

Question 2

The rows of the table are called

Answer 2

Periods

Question 3

The collumns are called

Answer 3

Groups

Question 4

Metals are on the ___ of the table

Answer 4

Left side

Question 5

Non-metals are on the ___ of the table

Answer 5

Right side (the divide is the black staircase)

Question 6

What are the elements in the middle

Answer 6

elements in the middle of the table, labelled above as metalloids, have intermediate properties

Question 7

Group names to know

Answer 7

Group 1 Alkali metals
Group 2 Alkaline earth metals
Group 7 Halogens
Group 8 Noble gases

Question 8

Properties of matels

Answer 8

Mostly shiny, silvery solids
generally dense
high m.p. and b.p.
conduct heat
conduct electricity
are malleable and ductile
found on the LHS of the PT

Question 9

Properties of non-metals

Answer 9

dull solids, or liquids or gases
not usually dense
often low m.p. and b.p.
poor conductors of heat
do not conduct electricity
are brittle and cannot be drawn into wires
found on the RHS of the PT

Question 10

Metal oxides are _

Answer 10

Alkalis

Question 11

Non-metal oxides are _

Answer 11

Acidic

Question 12

chemical reactivity of alkali metals

Answer 12

all the alkali metals are very reactive and are stored under oil to prevent contact with oxygen or water vapour Eg. 4Na(s) + O2(g) -> 2Na2O(s)
alkali metals react with non-metals to form ionic compounds which are all soluble

Question 13

How chemical reactivity works

Answer 13

reactivity decreases down group: a halogen reacts by gaining an electron which is added to its outer shell (X -> X-) so the larger the halogen the further the outer shell is from the nucleus and the less reactive the halogen is
i.e. Cl2 is a better oxidising agent (more readily reduced) than Br2 etc. Hence:

Question 14

Facts on noble gases

Answer 14

include He, Ne, Ar, Kr, Xe, and Rn
they are all colourless unreactive monatomic gases
their density and m.p./b.p. ­ down the group
Uses of Noble Gases:
He - airships (v. light + inert gas)
Ne - advertising signs (neon lights)
Ar - light bulbs (inert atmosphere around hot filament)
Kr - Lasers

Question 15

Everything on transition metals

Answer 15

e.g. Fe, Cu, Co, Ni, Ag, Au etc.
typical properties of transition metals include: high m.pt e.g. iron has a m.pt of 1810 K
high density and very hard e.g. tungsten
coloured compounds e.g. copper(II) salts are often blue, iron(II) salts green, etc.
variable oxidation state/valency e.g. iron compounds can contain Fe2+ or Fe3+
Uses of Transition Metals:
Catalysts - Fe in Haber Process, Ni in manufacture of margarine
Coins - Made from alloys involving Ni
Pipes - Cu doesn’t react with water and is easily bent round corners
Wiring - Cu is a very good conductor of electricity