elements<br />An element is a pure substance consisting of only one type of atom.<br />It is distinguished by it’s atomic number, or the number of protons in it’s nucleus.<br />
atoms<br />An atom is a basic unit of matter. Also it is the smallest recognized division of a chemical element.<br />
metals<br />A metal is a chemical element, compound or alloy, characterised by high electrical and heat conductivity. It’s also ductile (it can be stretched without breaking) and tensile (it can be bent without breaking).<br />
non-metals<br />A non-metals (such as hydrogen & carbon) are poor conductors of heat & electricity, and are dull and brittle in solid form. The usually have lower densities, freezing points and boiling points than metals.<br />
the periodic table<br />The periodic table is a display of all the pure chemical elements. The current standard table contains 117 elements.<br />
compounds<br />A compound is two or more different elements fused together. Some examples are aluminium, baking soda and tin.<br />
chemical reactions<br />A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Examples are a plant changing sunlight into energy or metal going rusty.<br />
identification<br />You can tell if there is a chemical reaction happening because either heat, light, precipitate or gas will be produced.<br />
Chemical changes<br />A chemical changes is when the bonds of an object are broken and new bonds are formed, creating a new substance (e.g. cooking, corn kernals into popcorn). <br />
physical changes<br />In a physical change, the substance doesn’t change chemically at all, but takes on a different form (e.g. water freezing and melting)<br />
reaction rate<br />A reaction rate is the rate that two substances combine to form a chemical reaction. For example, iron rusting is a slow reaction rate. Fire burning a log into charcoal is a fast reaction rate.<br />
Factors of reaction rate<br />. Concentration – how diluted or pure the substance is.<br />. Temperature – how hot/cold the environment is.<br />. Catalyst – whether or not there is another substance to provide a pathway.<br />. Surface area – powder is going to dissolve faster than a tablet.<br />
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