Chemistry
Atoms and Elements
Word | Pronunciation | Meaning |
atom | The smallest part of an element you can get. | |
element | All the atoms in an element are the same. A substance that cannot be split up into anything simpler by chemical reactions. | |
symbol | The letter or letters that represent an element. | |
periodic table | Table that shows all the elements | |
metals | Elements that are shiny, conduct heat and electricity well, and often have high melting and boiling points. | |
non-metals | Elements that are usually not shiny, and do not conduct heat and electricity well. | |
compounds | Substances that can be split up into simpler substances. | |
molecule | Two or more atoms joined together. | |
bond | Force holding atoms together. | |
mixture | Two or more different substances that are not joined to each other. | |
alloy | A mixture of different metals. |
Chemicals
Word | Pronunciation | Meaning |
hydrogen | A gas which is given off when metals react with acids. It burns with a squeaky pop. | |
carbon dioxide | A gas which will put out a lighted splint and turn limewater milky. | |
limewater | A chemical that goes cloudy when carbon dioxide is bubbled through it. | |
oxide | A compound that includes oxygen. | |
sulfates | Compounds containing sulphur and oxygen. They are the type of salt formed when a reaction with sulfuric acid occurs. | |
salt | A compound made when acids react with metals or bases. Many salts are chlorides, sulphates or nitrates. Common salt is sodium chloride. | |
fuel | A chemical that can release energy when it reacts. | |
rust | Substance formed when iron or steel reacts with oxygen and water. | |
chemical energy | The kind of energy stored in chemicals. | |
acid rain | Rain containing sulfuric and nitric acid. |
Reactions
Word | Pronunciation | Meaning |
chemical reaction | A change where new substances are formed. | |
physical change | fizz-ick-al | A change where no new substances are formed. |
reversible change | A change in which what you end up with can easily be turned back into what you started with. | |
chemical formula | A combination of symbols and numbers that show how many atoms of different kinds there are in a particular compound. | |
symbol equation | A way of writing out what happens in a chemical reaction using the symbols that represent the substances involved. | |
word equation | A way of writing out what happens in a chemical reaction. | |
reactants | Chemicals that join together to form a new substance. | |
product | New chemical formed in a chemical reaction. | |
reactive | A substance that reacts with many other substances, or reacts very easily. | |
unreactive | A substance that reacts with few other substances, or reacts very slowly or not at all. | |
reactivity Series | A list of metals which shows them in order of their reactivity, with the most reactive at the top. | |
displacement | A reaction that occurs when a more reactive metal ‘pushes’ another metal out of a compound and takes its place. | |
neutralisation | Mixing an acid and a base together to make a solution with a pH of 7. | |
oxidation | A reaction that occurs when an element or compound combines with oxygen. | |
decompose | Break down into simpler parts. | |
corrosion | When stone or metal reacts with chemicals in air or water and is worn away or changed into a different substance. | |
combustion | The scientific word for burning. | |
law of conservation | The idea that the total mass of all the reactants in a chemical reaction is the same as of mass the total mass of all the products. |
Properties
Word | Pronunciation | Meaning |
property | Something that is used to describe how a material behaves and what it is like. Hardness is a property of some solids. | |
electrical conductor | Something which allows electricity to flow through it easily. | |
heat conductor | Something which allows heat to flow through it easily. | |
high melting point | Something with a high melting point has to be at a very high temperature before it melts. It is a solid at room temperature. | |
low boiling point | Something with a low boiling point will turn into a gas at a relatively low temperature. It can be a solid, liquid or gas at room temperature. | |
low melting point | Something with a low melting point turns into a liquid at a relatively low temperature. It can be a solid, liquid or gas at room temperature. | |
magnetic | A metal (iron, nickel or cobalt) that can be magnetised or attracted to a magnet. |