C1 Revision Notes
Inside The Atom
- At the centre of every atom is a nucleus.
- The nucleus contains protons and neutrons.
- The nucleus is surrounded by electrons that move around it.
- The electrons are organised into shells. The first shell's maximum is 2, the second shell is 8 and the third shell is 18.
- The protons and neutrons are the atomic number.
- Electrons are the atomic mass - atomic number.
- In the periodic table, columns are arranged by the amount of electrons on the last outer shell from 1 to 8.
- The rows are called periods.
- Elements react depending on the amount of electrons on the outer shell.
- An element with 8 electrons on its outer shell is stable and unreactive.
- There are two types of bond
- Ionic bonding: When non metals combine with metals. The electrons are transferred from the metal atom to the non metal. The are both left with an electric charge. Charged particles are ions. The metal ion is positive and the non metal is negative.
- Covalent bonding: Atoms of two of more elements. They join to form compounds by sharing electrons.
- Must be balanced
- State symbols
- (s) is for solid
- (l) is for liquid
- (g) is for gas
- (aq) is for aqueous which means dissolved in water
Building With Limestone
- Limestone is an off-white rock formed from shells and fossils of sea creatures and coral from years ago.
- Limestone is mainly calcium carbonate : CaCo3
- Limestone is extracted from the ground in a quarry.The top layer of the soil is removed and then the rock is blasted with explosives which dislodges pieces of limestone.
- Limestone is used for building, fountains of most roads, in cement, in mortar, in concrete, to make iron, to make steel and to make glass.
Advantages Of Using A Quarry
- Jobs for people in an area with little industry
- More, better paid jobs to boost the economy
- More people move to the area which means more services and leisure
- Roads are improved for the lorries
- The disadvantages are minimised by allowing a quarry only to work during the weekdays, using railways, restricting the size of the quarry and having fewer but better quarries.
Disadvantages Of Using A Quarry
- Damages the landscape
- Loss of wildlife habitats
- Noise and vibration from blasting, machinery and vehicles
- Dust pollution
- Traffic congestion
- CaC03(s) -> CaO(s) + CO2(g)
- (This is thermal decompostion)
- CaO(s) + H2O(l) -> Ca(OH)2(s)
- (This is lime/calcium hydroxide)
- Lime is alkaline so is used to neutralise substances that are too acidic. eg. soil
- Ca(OH)2(aq) is limewater.
- When carbon dioxide is present in limewater it goes cloudy because of the tiny solid particles of calcium carbonate that form
- Materials made from limestone:
- Cement is made by heating limestone and clay. When you add water it goes hard
- Mortar is made by mixing cement, sand and water. This slowly sets as a solid.
- Concrete is made by mixing cement, sand, gravel and water. This is very…