Chemistry Unit 1

HideShow resource information
  • Created by: Eliza
  • Created on: 19-05-13 18:19

The fundamental ideas in chemistry

  • The three subatomic particles are protons, electrons and neutrons.
  • 2 electrons fill the inner shell, 8 fill the rest of the shells.
  • Elements in the same group of the periodic table all have the same number of electrons in their outer orbitals.
  • To calculate the number of neurtons in an atom you should take the number of protons form the mass number (mass no. - protons).
  • When atoms bond, they gain/lose/share electrons so that they end up with a full outer shell.
  • Covalent bonding involves the sharing of electrons. It happends between non-metals (of the same atom-element, 2 different atoms, or a compound), in order for the atom to have a full outer shell.
  • Ionic bonding involves electrons been given from one atom to another. It happens between non-metals and metals, in order for the atom to have a full outer shell.
1 of 7

Rocks and building materials

  • The formula of limestone is CaCO3.
  • The limestone cycle:                                                                                                         1.Limestone/Calcium Carbonate (CaCO3)                                                                           [heated strongly]                                                                                                    2.Quicklime/Calcium Oxide (CaO)                                                                                              [2-3 drops of water]                                                                                                               3.Slaked Lime/Calcium Hydroxide (Ca(OH)2)                                                                     [dissolve it in water]                                                                                                                        4. Lime Water/Calcium Hydroxide Solution (Ca(OH)2)                                                             [carbon dioxide bubbles]
  • Advantages of limestone quarrying in a National Park is that it creates many jobs for unemployed, there is huge demand for the materials quarried, therefore if we quarry there will be more material to supply/sell.

 

 

2 of 7

Metals and their uses

  • An ore is a material that conatins metals in such quantities that makes it worth mining for.
  • Metals above carbon in the reactivity series are extracted from their ores by the method of electrolysis (the breaking down of a compound uisng electricity).
  • Electrolysis is expensive because it is needed for the breaking down of the compound.
  • An alloy is a metal made from two combined metallic elements.
  • Titanium is a useful metal because it resists corrosion (lasts a very long time) , it has a very high melting point, it is light and also strong- this makes it very useful as an a airplane engine or an artificial joint. However, electrolysis must be used to extract it.
3 of 7

Fuels from crude oil

  • A hydrocarbon is a compound made from hydrogen and carbon.
  • Crude oil is separated by a process called fractional distillation.
  • In hydrocarbons, all the carbon atoms have 4 chemical bonds.
  • The gas that causes acid rain is sulphur dioxide.
  • When a hydrocarbon burns, the products are always water and carbon dioxide.
4 of 7

Products from oil

  • Long hydrocarbons are cracked because the products (shorter hydrocarbons) are more useful, e.g aviation fuel.
  • Cracking method:                                                                                                                     1.Place wool soaked in hyrdocarbon in the end of a boiling tube, alongside broken pot.                                                                                                                                            2.Put a delivery tube in the end of the boiling tube.                                                                   3.Put the end of the boiling tube into a beaker full of water.                                                   4.Begin to heat the end od teh boiling tube with a bunsen burner.                                      5.Collect the gas bubbles with a testube- place it upside down, just above the end of the delivery tube in the water.                                                                                                                    6.Place a bung in the end of the testube collecting the gas once satisfied with the amount collected.
  • Alkenes are unsaturated, therefoer they conatine a double bond to the carbon (betwenn hyrdogen and carbon)
  • Polymerisation is a chemical process that combines several monomers to form a polymer(ic)compound.
  • Ethene is turned into ethanol by fermentaion.

 

 

5 of 7

Plant oils

  • Methods of extractig oils from plants are crushing and pressing the plant, or by dissolving in a solvent- once the oil is dissolved, the solvent is removed by distillation, and impurities such as water are also removed, to leave pure oil.
  • Oils are hardened using hydrogenation- adding hydrogen to the solition at about 60 degrees centigrade
  • To test for unsaturation in an oil you can see if it is liquid at room temperature, as most are.
  • The most common use of plant oils is in food. You can also use bromine water- it becomes colourless when in an unsaturated solution and if it stays the same colour then it is saturated.  
  • An emulsifier is a substance that stops the oil and water from separating into layers. 
6 of 7

Earth and atmosphere

  • The layers of the earth are: the crust, the mantle, the outer core and the inner core.
  • Rock formations and volcanoes occur when tectonic plates meet.
  • Before Alfred Wegener, scientists thought that continents were formed as the Earth cooled.
  • The main gases in the atmosphere are Nitrogen, Carbon dioxide, Argon and Oxygen.
  • Carbon dioxide in the atmosphere has decreased over the past four billion years, because plants use it in photosynthesis and it is/was absorbed into the oceans.
7 of 7

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all resources »