Yesterday, we looked at the bonding in hydrogen, which is covalent. Hydrogen has one electron. It likes to have two electrons so it shares an electron with another hydrogen atom, forming a hydrogen molecule H₂. Oxygen(O₂) has the same sharing of electrons in a slightly more complicated way, which we will look at next week, in addition to ionic bonds.

We also saw that atoms contain 3 particles – neutral neutrons and positive protons in the nucleus, and negative electrons in shells moving around the nucleus. Between the electron shells and the nucleus is empty space - in fact most of an atom is in fact empty space!

An animation of the covalent bonding in chlorine

The fourth thing that speeds up reactions after temperature, concentration and surface area are catalysts. These chemicals are not changed by the reactions they speed up.  Catalysts breaks down car exhaust fumes and are used in the Haber process to make ammonia. Hydrogen peroxide is broken down by manganese dioxide and by liver (biological catalysts are known as enzymes) into water and oxygen.

can you explain what they are trying to do in the video?

interactive explanation and test

rickets – bones deformed

Polymers are chemicals made up of repeating units called monomers.

Natural polymers include starch and cellulose ( monomer is glucose)

Synthetic polymers include: polythene, polypropene, polystyrene, polyvinylchloride, nylon and kevlar.

You must know the difference between thermosetting and thermoplastic polymers and why they have different properties.

link to bitesize

• we looked at the reaction between calcium carbonate and hydrochloric acid. In this reaction, the carbon dioxide is collected in a gas syringe. We timed how long it took to collect a certain volume with large lumps, medium lumps and powder.
• Which was quickest and can you explain why in terms of surface area?
  

interactive lesson on rates of reaction

notes on the four types of materials you need to know about

http://www.divshare.com/download/2101052-86f

The body of Del boy and Rodney’s van is a composite (GRP)