2. Download short revision clips to your computer or mobile phone from the following website: Be sure you use the clips relevant to your year! Revision&rt=Videos Revision&rt=Videos 3. Test yourself using Doc Brown’s quizzes. Be sure you test yourself on the test relevant to your year! 1. The BBC bitesize website has lots of information, activities and quizzes for you to revise from. Remember to choose the topics you have covered in year 7! Useful Websites: Year 7 Science Revision The topics that you will tested on on Monday 2 nd December are: Energy resources Acids and alkalis Cells, tissues and organ systems Revision is very important if you want to achieve your best. Our memory works by constantly using information. Revising means we are using the information.

Energy Resources Non- renewable energy Also know as fossil fuels. Examples of fossil fuels: coal oil gas They are non-renewable because they have taken millions of year to make and we can’t make them in our lifetime (they will run out). Renewable energy resources Examples of renewable energy resources are: solar power wind power tidal power wave power hydroelectric power geothermal power biomass They are renewable because they will not run out like fossil fuels will in our lifetime. Recycling, Reusing, Reducing Recycling, reusing, reducing helps the environment because it means new objects don’t have to be made using energy resources. This can reduce pollution. Examples of what you could do are: using reusing plastic bags, turning lights off when you don’t need them, recycling aluminium cans. Energy Resources and the environment Geothermal Energy Uses the heat energy in the Earth to generate electricity Tidal Energy Uses the gravitational potential energy in tides to generate electricity Biomass Uses the chemical energy in living things to generate electricity Wave Energy Uses kinetic energy in waves to generate electricity + no pollution - Found in very few places in the world Hydroelectric Energy Uses flowing water (kinetic energy) to generate electricity + no pollution - Needs lots of machines to get enough energy, look ugly + reliable as always two tides a day - Costs a lot to build a local dam, could cause flooding + no special equipment needed so can used in poorer countries - Large areas of land are needed to grow enough trees + no pollution - Costs a lot of money to build a dam Wind Energy Uses the wind (kinetic energy) to generate electricity + no pollution, quite cheap and easy to build - Some people think they are ugly, only works if windy! Solar Energy Uses the sun (heat energy) to generate electricity or heat up water Nuclear Energy Uses the chemical energy in metals to generate electricity + no pollution, renewable (the sun won’t run out any time soon!) - expensive, only works if sunny! + no harmful gases produced - non-renewable (uranium will run out), produces dangerous radioactive waste

Acids and Alkalis Acids Acids contain the element hydrogen (H). Examples of acids in the home are vinegar, oranges and grapefruits. Examples of acids in the science laboratory are hydrochloric acid and sulphuric acid. Hazard Symbols pH scale Indicators Indictors are used to say whether liquids or solutions are acidic, neutral or alkaline Alkalis Alkalis contain a hydroxide (OH - oxygen and hydrogen). Examples of alkalis in the home are soaps, oven cleaners and washing powders. Examples of alkalis in the science laboratory are sodium hydroxide, potassium hydroxide. Litmus paper Litmus paper is an indicator. If in a neutral solution it’s colour is unchanged, it turns red in an acidic solution and blue in an alkaline solution. Universal indicator can be used to measure how strong or weak an acid or alkali is (this means it gives more information than Litmus paper). Universal indicator is a mixture of several dyes extracted from plants. The overall colour the indicator solution is compared with the range of colours in the pH scale (above). A neutral solution has a pH of 7. An acidic solution has a pH of 1 to 6 (strong acid = 1 to 3, weak acid = 4 to 6). An alkaline solution has a pH of 8 to 14 (weak alkali = 8 to 10, strong alkali = 11 to 14). Neutralisation Reactions between acids and alkalis are called neutralisation reactions. We use neutralisation reactions to help us: Indigestion tablets to reduce excess stomach acid Farmers add lime (alkali) to soil to neutralise excess acidity from acid rain. Toothpaste (alkali) neutralises acid that builds up on our teeth. Highly flammable – easily catches fire Corrosive – attacks and destroys living tissues i Irritant– can cause reddening and blistering of the skin h Harmful – e.g. when swallowed, breathed in Toxic - Can cause death Oxidising – provides oxygen to make other substances burn Radiation – possibly causing DNA damage Acids and alkalis are corrosive and have to be used carefully. Scientists use hazard symbols to help know about the dangers of chemicals. Explosive – substance that can explode Environmental hazard – substance that is dangerous to the environment

Cells Animal and plant cells Functions of animal and plant cell parts Specialised Cells CellFunctionAdaptation Red blood cell Nerve cell Egg cell Sperm cell Root hair cell Palisade cell Absorbs and carries oxygen around the body Large cell membrane surface area Carries messages around the body Long and thin Develops into an embryo Large and contains lots of cytoplasm Fertilise the eggHas a long tail allowing it to move Absorb water Large cell membrane surface area Site of photosynthesis Contains lot of chloroplasts PartFunction (job)Found in animal cells Found in plant cells Cell membraneControls what passes into and out of the cell  NucleusContain the genetic material and control the cell activities  CytoplasmJelly-like liquid where important chemical reaction take place  Cell wallMade of cellulose and supports the cell, helping it keep its shape  VacuoleContains cell sap  ChloroplastsContain chlorophyll which traps light for use in photosynthesis (where plants make their own food) 

Tissues, Organs, Systems Tissues Organ Systems An organ system is made from a group of different organs, which all work together to do a particular job. Organs An organ is made from a group of different tissues, which all work together to do a particular job. Here are some examples of organs: heart lung stomach brain leaf root Circulatory SystemDigestive System Nervous System Respiratory System Contains: nose, trachea, lungs, bronchus, bronchioles and alveoli Job: To bring oxygen into your body, and remove the carbon dioxide from your body. Contains: nerves, brain, spinal cord. Job: To carry messages to difference part of the body heart capillaries Job: To transport blood and substances around the body. Job: To break food we eat into smaller pieces so that we can absorb it into our blood. Animal cells and plant cells can form tissues, like muscle tissue. A living tissue is made from a group of cells with a similar structure and function, which all work together to do a particular job. Here are some examples of tissues: muscle the lining of the intestine the lining of the lungs phloem (tubes that carry dissolved sugar around a plant) root hair tissue (for plants to take up water and minerals from the soil)