Atoms have a small nucleus surrounded by electrons: THE ATOM.
- It's in the middle of an atom
- It contins protons and nuetrons
- Protons are positivley charged
- Nuetrons have no charge
- The nucleus has a positive charge overall because of the nuetrons
- Move around the nucleus
- They're negativley charged
- Theyre tiny, but they cover a lot of space
- They occupy the shells around the nucleus.
Number of protons equals number of electrons
- Atoms have no charge overall, they are NUETRAL
- The charge on the electrons is the same size as the charge on the protons- but opposite.
- This means the number of protons always equals the number of electrons in an atom.
- If some electrons are removed, the atom becomes charged and is an ion.
Atoms can have different numbers of protons, nuetrons and electrons. However it is the amount of protons in the nucleus which decide what type of atom it is.
1st shell: 2 electrons
2nd and 3rd shell: maximum of 8 electrons
- Consists mainly of calcium carbonate (CaCO3)
- It can be used to create glass,cement or concrete
- When you heat it strongly, it breaks down to form quickline or calcium oxide (CaO) This is called thermol decomposition and it also produces carbon dioxide.
Calcium Carbonate -> calcium oxide + calcium dioxide
CaO3 -> CaO + CO2
Metals are found in the earths crust.
A rock containing a reasonable amount of a metal is called a metal ore. Some metals are so unreactive, that they do not combine with other metals and are found in their native state.
The way in which they react, depends on where they are in the reactivity series. Many metals are found in their metal oxide form, like lead, zinc and copper. Carbon can be used to extract these metals from their ores as it is more reactive and higher in the reactive series
when you heat the metal oxide with the carbon, the carbon removes the oxygen to form carbon dioxide.
This leaves the pure element behind: Metal oxide + carbon -> metal+ carbon Dioxide
We call the removal of oxygen this way, a reduction reaction.
Independent variable: what you change
Dependent variable: what you measure
Control variable: what you have kept the same
- A thick black liquid, a mixture of hydrocarbons
- Comes from microscopic animals that died millions of years ago
- Hydrocarbon is compounds of carbon and hydrogen atoms
- FRACTIONAL DISTILATION is a way of seperating the "fractions" evaporating then condensing the parts of the mixture according to their boiling point... (crude oil)
Alkene: a saturated hydrocarbon (a carbon that cannot fit anymore hydrogen atoms into it)
HYDROCARBON: A molecule that contains only hydrogen and carbon.
Alkane products all end in ANE:
The Earths Crust
The Earth has a Crust, Mantle, outer and inner core.
The crust which we live on, surrounded by our atmosphere, is very thin. Below that is the mantle which has all the properties of a solid, except it can flow very slowly.
Within the mantle, radioactive decay takes place, producing a lot of heat which causes the mantle to flow in convection currents.
At the centre of the earth is the core, which is said to be made of iron and nickle.
The Earth's crust and upper part of the mantle are broken into large pieces called tectonic plates. These are constantly moving at a few centimetres each year. Although this doesn't sound like very much, over millions of years the movement allows whole continents to shift thousands of kilometres apart. This process is called continental drift.
The plates move because of convection currents in the Earth’s mantle. These are driven by the heat produced by the natural decay of radioactive elements in the Earth.
Where tectonic plates meet, the Earth's crust becomes unstable as the plates push against each other, or ride under or over each other. Earthquakes and volcanic eruptions happen at the boundaries between plates, and the crust may ‘crumple’ to form mountain ranges.
Present and past day atmosphere
Phase 1: Volcanoes gave out gases.
- 4.6 billion years ago earth was formed.
- the earths surface was originally molten, any atmosphere was boiled into space. however things cooled down and a thin crust was formed, but volcanoes were still errupting
- They gave out gases such as CO2, water vapour, Ammonia and methane
Phase 2: Green plants evolved and produced oxygen.
- The plants obsorbed the CO2 and turned into oxygen, photosynthesis.
- first bacteria started to form
- the earth became lower than 100 degrees
Phase 3: Ozone layer allows evolution of complex animals.
- The oxygen killed of some early organisms that couldnt tollerate it.
- The oxygen created the ozone layer which blocked harmful rays from the sun
- there is virtually no C02 left now!
our present day atmosphere
- 78% nitrogen
- 21% oxygen
- 0.9% argon
- 0.04% carbon dioxide
- trace amounts of other gases
alpha beeta and gamma
Alpha radiation: Alpha radiation consists of positive Alpha particals. An alpha partical is the same as the nucleus of a helium atom
Beeta radiation: Beeta radiation consists of fast moving negativeelectrons which come from the nucleus of the splitting atom.
Gamma radiation: Gamma Radiation is a very high frequency electromagnetic radiation. It belongs to the same family as radio waves, light and X-rays. It can travel a long way and is very penetrating. It also belongs to the electromagnetic spectrum.
fission and fusion.
Nuclear Fission: The splitting of atoms
Nuclear Fusion: The joining of atoms,the joining of 2 small nuclei of atoms, producing very large amounts of energy, heat and light. It takes place in the sun and in the stars.
Life cycle of a star.
Proto star: Cloud of cold dust and gas.
Main sequence star: Long stable period, billions of years until hydrogen runs out.
Red Giant / Red super giant
White dwarf / Supernova
Black dwarf / Nuetron star / black hole