Summer Term Chemistry Recap 2020
Separation of Mixtures
REACTIONS
Rates of Reactions
Plant Nutrition
Environmental Chemistry
Extraction of Metals
Atoms
Reactions start at a certain speed and get slower until they
stop.
The speed of a reaction is called the rate of the reaction. Reactions take place when particles collide with a certain amount of energy.
The reactivity series is a series of metals, in order of reactivity from highest to lowest. It is used to determine the products of single displacement reactions, whereby metal A will replace another metal B in a solution if A is higher in the series.
Testing for starch in leaves
Green plants make their own food through a
chemical process known as PHOTOSYNTHESIS.
Process
LIGHT ENERGY from the sun, trapped by
CHLOROPHYLL is used to combine
CARBON DIOXIDE with WATER to produce
GLUCOSE and OXYGEN.
Iodine is used to test for starch. It reacts with starch and changes
colour from brown to blue-black.
All substances are made up of tiny particles called atoms.
There are 118 different types of atoms called elements and
these are arranged in a chart called the periodic table.
Elements
Compounds
An element is a substance that cannot be broken down into any other substance. There are about 100 elements, each with its own type of atom.
A chemical compound is a chemical substance composed of many identical molecules composed of atoms from more than one element held together by chemical bonds.
A mixture contains two or more substances that are mixed together but have not reacted with each other. A solution is a special type of mixture that is made when a solid dissolves and mixes in a liquid. Mixtures are either homogenous or heterogeneous.
Method's of Separation
decanting
filtration,
evaporation
distillation
chromatography
Elements that easily take part in a chemical reaction are considered as reactive and those that do not are unreactive.
Some metals occur naturally in nature e.g. gold, silver and platinum and others are found as ores e.g. iron, copper, tin and lead. The reactivity series can help us to predict how difficult it will be to separate/extract a metal from its ore.
Humans rely on burning fossil fuels to power, and planes and warm homes.
Pollutants such as sulfur dioxide and nitrogen dioxide released into the air dissolve in rain water to form strong acids which we call acid rain.
Global warming is the ongoing rise of the average temperature of the Earth's climate system
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