Year 9 Science Examination 2007 Summary of Topics covered. Skills in Science What lab equipment is used for. Safety rules of the lab Interpreting diagrams, graphs, text etc Parts of a Bunsen burner, how to use a Bunsen burner, comparing Flames What lab equipment is used for Equipment symbols / how to draw 2D scientific diagrams Fair Testing Line and bar graphs The separation of substances depends on differences in their physical properties; for example, one solid may be soluble and the other insoluble. Separation techniques: dissolving, filtering, evaporating, distillation, magnetic separation, and chromatography. Particles & the atom Matter has mass and occupies space; there are three states of matter - solids, liquids and gases. Mass is the amount of matter in an object; it is measured in kilograms or grams, using a balance. Density is how much mass is packed into a measured volume. Density = mass/volume Matter can be changed from one state into another when heat is added or removed; changes of state boiling, condensing, evaporating, subliming, melting, freezing (solidifying) The particle theory of matter says that all matter is made of particles too small to see. Theses particles have space between them, attract each other, are constantly moving, and move faster with increase of temperature. Mixtures contain two or more different substances
When a substance dissolves, it is said to be soluble. Substances which do not dissolve are insoluble. A solute is a substance that dissolves in a solvent to form a solution. In a suspension the solid settles to the bottom when left standing. Solutions do not settle. A dilute solution contains only a small amount of solute in a given volume of solvent. A concentrated solution contains a large amount of solute. Atoms are the basic building blocks of all matter. A molecule is two or more atoms joined together by chemical bonds. An element is a pure substance made of atoms of only one type. It cannot be decomposed into simpler substances by chemical reactions. There are about 100 different elements, each with its own symbols. A compound is a pure substance made up of two or more different elements that are chemically joined together. The chemical formula for a compound tells you what elements it contains. It also tells you the ratio of the atoms of the elements. Eg CuSO 4 Chemical reactions produce new substances by rearranging atoms. The compounds that are formed have different properties from the original substance(s) with properties different from the original substance. Atoms are composed of a positively charged nucleus surrounded by tiny negatively charged electrons. Inside the nucleus are protons (positive charge) and neutrons (no charge). Know the rules for "building atoms" : atomic number = no. of protons and no of orbiting electrons; mass number = number of protons + neutrons. Electrons are found in regions called shells (energy levels). 1st shell holds up to 2 electrons, 2 nd and 3 rd shells up to 8 electrons each. Relate the properties (chemical and physical) of common metals to their uses e.g. Copper, iron, gold...zinc Recognise some common elements by their description of physical properties and chemical properties
Cells and Classification Living things (called organisms) move, respire, are sensitive, grow, reproduce, excrete and need nutrition. MRS GREN Classification is a process of sorting objects which have similar characteristics. One way to do this is by using a key. Designing and using keys. Living things can be classified into groups by observing their structural and functional characteristics. Most biologist classify organisms into Kingdoms = animal, plants, microbes Animals can be classified into two main groups: vertebrates which have bones (mammals, birds, fish, amphibians & reptiles) and invertebrates which do not. Green plants make their own food by the process of photosynthesis. Animals rely on other organisms for food All organisms are made of cells. There are many different types of cells, with different shapes and different functions. All cells contain a nucleus, cell membrane, cytoplasm and organelles. Plant cells also contain a cell wall and large vacuoles. A flowering plant's life cycle includes the formation of flowers, pollination- the transfer of pollen grains, containing sperm cells, from the ripe anther to the stigma (by insects or by wind), fertilisation and the growing of seeds. Seeds are dispersed in many ways, by animals, water and wind. A seed develops from a fertilised ovule. The seed contains the plant embryo. Germination occurs when the seed starts to grow roots and a stem. Germination needs water, oxygen and warmth to occur
Light & Sound What are light sources? Light travels in straight lines. The law of reflection states that the angle of incidence is equal to the angle of reflection. Ray diagrams: How to draw. Ray diagrams for plane, concave and convex mirrors. Ray diagrams for concave and convex lenses. Refraction of light occurs when a beam of light passes from one transparent substance into another, eg from air to water. The amount of refraction depends on the substance White light can be dispersed by a glass prism into the seven colours of the spectrum. ROYGBIV A coloured object reflects some colours and absorbs the rest. The colour you see depends upon the colours that are reflected. Different colours can be made by mixing different coloured lights (addition) or by mixing paints Sound waves are produced by vibrating objects and travels through gases, liquids and solids. The speed of sound depends on the type of substance and on the temperature. Light is a form of electromagnetic radiation carried by waves and which can travel through a vacuum. The speed of light is much greater than the speed of sound and is slightly different substances. The human eye: structure. Your eye contains two types of vision receptors. One type detects colours and the other detects the brightness of the light. Vision problems can be caused by an out-of-shape eyeball, or a faulty lens. These problems can usually be corrected with spectacles or contact lenses. Long and short sightedness. Sounds are made by vibrating objects. These vibrations eventually pass into the inner ear where they are detected by the hearing receptors Constant loud sounds can damage the hearing and cause a hearing loss.
Environment The Earth rotates on its axis once every 24 hours, causing day and night. It take's one year to revolve around the sun. A gravitational force of attraction keeps the Earth in its orbit around the Sun. The seasons are caused by the revolution of the Earth and the tilt of its axis. Tides are caused by the Earth's rotation and the gravitational pull of the Moon (& the sun). Able to identify and explain main terms and symbols found on weather maps. Identify cloud types. Know what causes wind, cold and warm fronts, low and high pressure systems Air is a mixture of gases, consisting of nitrogen (80%) and oxygen (20%) plus small amounts of carbon dioxide, water vapour and other gases. The atmosphere consists of three layers, the troposphere (lowest), the stratosphere and the ionosphere. Water is essential to life. Water dissolves many substances with which it comes into contact. Water is treated before we drink it to make it clean, free from bacteria and pleasant to taste. Sewage is collected and cleaned at a waste water treatment plant before it is returned to the environment. Water evaporates from the surface of the earth, condenses and returns as rain, hail and snow. This is called the water cycle. Soil erosion occurs when soil is broken up by raindrops, and carried away by running water. Soil can be blown away by winds during a drought. Ways of minimising erosion. Problems due to flooding.
The Human Body What is food needed for? Food types: carbohydrate, protein, fats, vitamins & minerals. Teeth. Types of teeth. How teeth are related to diet (herbivore, omnivore, carnivore). Skulls. The role of saliva in digestion. The breakdown of starch to sugar by saliva. The human digestive system: Parts and function. The purpose of digestion. Food tests: Test for starch, sugar and protein. Transport of materials around the body by blood food, oxygen, hormones, waste. Blood: red blood cells, white blood cells, plasma, platelets. Heart: structure and function. Pulse: Effect of exercise on the pulse Lungs: structure and function. Effect of smoking on health