Tag Archives: Chemistry
The Three States of Matter
The Three States of Matter The three states, SOLID, LIQUID and GAS are called the three states of matter (see Kinetic Theory) The boiling point of a substance is the temperature that causes it to change from a liquid to … Continue reading →
The Sun and the Water Cycle
Nearly all energy we use on the Earth starts with energy from the Sun. The Sun powers wind, tides, and the water cycle The Water Cycle • Energy from the Sun (1) causes water from the sea to evaporate (2). … Continue reading →
Activity series
Sometimes called the Reactivity series Reactions with carbon Displacement reactions A list of elements (usually metals) arranged in an order to show how easily they form compounds. Some elements arranged in order of chemical activity. The rate of chemical reactivity … Continue reading →
Useful chemical reactions
A chemical reaction ALWAYS forms a new substance. Signs that show a chemical reaction has taken place are: i. A change in colour ii. A change in temperature (usually gets hot) Types of reaction Burning Decomposition Oxidation and reduction Neutralization … Continue reading →
Gases in the Air
Identifying gases in the air Air pollution Experiment to show the percentage of oxygen in the air The air is a mixture of gases, some of which are elements and some compounds. The approximate composition of air is: 78% … Continue reading →
Elements in the Earths crust
Rocks Most minerals come from rocks in the ground. Rocks from which we can obtain a metal are known as ores (eg Iron ore is a rock from which we can obtain iron). Some rocks (like chalk or limestone) are … Continue reading →
Elements
Elements, compounds and mixtures Elements in the Earth’s crust Obtaining metals from their ores There are about 100 elements in total, although only about 20 are in everyday use. An element is the simplest of all chemical substances. It … Continue reading →
Solutions
A solution is formed when a solid DISSOLVES in a liquid The solid that has been dissolved is called the solute. The liquid used to make the solution is called the solvent. Example: When salt is dissolved in water then … Continue reading →
Heating chemicals
Chemical change The three states of matter Change in Mass The Water Cycle Heating copper sulphate Heating magnesium ribbon If a solid chemical is heated several things could happen: It could melt (change from a solid to a liquid) … Continue reading →
