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An element is a substance made from the same type of atom. A periodic table shows all the elements known to exist. Elements are arranged in rows called periods and columns called groups. The periodic table has 8 groups: •Group 1 = Alkali Metals •Between Groups 2 & 3 = Transition Metals •Group 7 = Halogens •Group 0 = Noble gases The basic pieces of science equipment we use are: •Bunsen burner •Tripod •Gauze mat •Heat mat •Beaker •Test tube •Boiling tube •Test tube holders •Conical flask •Test tube rack •Evaporating dish •Filter funnel Elements Elements can be either metals or non-metals. Noble gases are unreactive. The Halogens are also very reactive e.g. Chlorine and Fluorine. Alkali metals are very reactive and have to be stored in oil e.g. Potassium, Sodium and Lithium. Metals conduct electricity and heat and non-metals do not. Malleable means the metal can be shaped easily e.g. into a candlestick holder. Metals can be both malleable and ductile. Carbon is the only nonmetal to conduct electricity. Ductile means the metal can be beaten flat e.g. gold foil and tin foil. An electrolyte is the name given to a liquid that conducts electricity in a circuit In a series circuit there is only one possible route for the electricity to travel around In a parallel circuit there is more than one route for the electricity to travel around – there are branching loops Circuit symbols Switch Lamp Cell Voltmeter Battery Ammeter Electricity Resistor Variable resistor Motor In a series circuit the current is the same at every point Buzzer Bell Wire A voltmeter is connected to a circuit in parallel An ammeter is used to measure the current in a circuit. Current is measured in Amps. An ammeter is connected to a circuit in series Household appliances that are connected to parallel circuits can be switched on and off separately In a parallel circuit the current from the branches add up to the current from the battery A voltmeter is used to measure voltage. Voltage is measured in volts. The voltage in each branch of a branches in a parallel circuit is equal to the voltage coming from the battery. The voltage is divided between all the components in a series circuit so there is none to return to the battery. Heat is the total amount of heat energy in an object Heat flows through a solid by conduction Air is a good insulator Temperature is the average speed of vibration of the particles Vibrating particles make other particles vibrate around them as this spreads through an object we say that heat is being conducted A substance that lets heat flow through it easily is called a conductor Some examples of good conductors of heat are: • Metals • Copper pipes • Single glazed windows Heat A substance that does not let heat flow through it is called an insulator Some examples of good insulators in the home are: • Double or triple glazed windows • Wall insulation • Silver backed board Convection currents can be used everyday by: • Birds to gain altitude • Inside the Earth magma flows • The Gulf Stream ocean currents The faster a particle vibrates the hotter it gets Radiant heat travels by Infra-red waves Heat may be transferred through a vacuum by radiation A black surface will absorb more radiant heat and a white or silver surface will reflect more Heat flows through liquids and gases by convection currents As the particles heat they rise and as they move up and away from the heat they cool and sink again, this creates a current A dull surface will absorb more radiant heat and a shiny surface will reflect more