Revision for C1
C1 1 Fundamental ideas
C1 2 Rocks and building materials
C1 3 Metals and their uses
C1 4 Crude oil and fuels
C1 5 Products from oil
C1 6 Plant oils
C1 7 Our changing planet
C1 1.1, 1.2 and 1.3
Atoms are made up of protons, neutrons and electrons. Nucleus
Particle
Charge
Mass
Proton
+1
1
Neutron
0
1
Electron
-1
0
Electrons are arranged in energy levels (shells).
The fourth shell can hold 18 electrons (but you don’t
The first shell can hold 2 need to go that far). electrons. The second shell can hold 8 electrons.
Electron configurations can be written 2,8,8,18.
The third shell can hold 8 electrons. All atoms want a full outer shell of electrons, and they will do that by gaining electrons, losing electrons or sharing electrons.
C1 1.4 Forming bonds
A metal atom gives electrons to a non-metal atom, so that both of them have full outer shells.
When drawing the electron configuration for an ion, we draw square brackets around it, and put the charge on the outside.
Electron configurations can be written Na [2,8]+ and Cl [2,8,8]-
-
+
Na
Cl
We draw the electrons as different shapes to show which atom they came from (dot and cross diagrams) Charges on ions from different groups
Group
Outer shell electrons
1
1
2
2
3
3
4
4
Electrons gained/lost
Loses
1
Loses
2
Loses
3
N/A
Ion charge
+
2+
3+
N/A
5
5
6
6
7
7
Gains 3 Gains 2 Gains 1
3-
2-
-
8
8
N/A
N/A
C1 1.4 Forming bonds
If the positive and negative ions have different charges, then you will need different numbers of ions to balance out the charge e.g. MgF2.
-
2+
Mg
F
Remember: Swap n’ drop
Swap the ion charge numbers, and drop them down to the bottom right of the element symbol. Get rid of the charge.
These ions are on your data sheet, so you don’t need to remember them.
Mg
F
-
2+
MgF2
F
Compound ions
If your compound has a compound ion
(OH-, NO3-, SO42-, CO32-, NH4+) and there is more than one of them, you need to put it in brackets.
E.G Mg(NO3)2, or (NH4)2O, or Al2(SO4)3
C1 1.4 Forming bonds
Covalent bonding is a shared pair of electrons.
Covalent bonding occurs between non metals. covalent bond
F
simplified dot and cross diagram
solid line
(one line
= 1 pair)
Group 4 elements share 4 electrons.
Group 5 elements share 3 electrons.
Group 6 elements share 2 electrons.
Group 7 elements and hydrogen share 1 electron. F
H
F
F
F–F
F
–
F
O
H
H
H
Cl
N
H
H
O
C
O
Balancing equations
+
+
CH4 + 2O2 CO2 + 2H2O
There are 4 hydrogens here.
You multiply the big number by the little number.
There are 4 hydrogens here, bonded together.
There are 2 molecules of oxygen not bonded together.
You can only change the BIG numbers in equations – we cannot change the small numbers or add or take away any reactants or products.
C1 2.1 Limestone and its uses
Carbon dioxide is formed from thermal decomposition of limestone and from burning methane. Argon and nitrogen come from the air.
Calcium
carbonate
CaCO3
Calcium oxide Carbon dioxide CaO +
CO2
Reaction of thermal decomposition limestone.
Methane is fuel for the fire to heat limestone.
C1 2.2 Reactions of carbonates
CaCO3(s) CaO(s) + CO2(g)
CaO(s) + H2O(l) Ca(OH)2(s)
Ca(OH)2(s) Ca(OH)2(aq)
Limestone is heated and breaks down (thermal decomposition) into calcium oxide (quicklime) and carbon dioxide. Calcium oxide (quicklime) is added to water to make solid calcium hydroxide (slaked lime). Solid calcium hydroxide
(slaked lime) is dissolved in water to make aqueous calcium hydroxide (lime water). Aqueous calcium hydroxide
(lime water) is added to carbon dioxide which makes calcium carbonate and water.
C1 2.3 Limestone reaction cycle and C1 2.4 cement and concrete
