Page 6 - Curriculum Visions Dynamic Book

Calcium
Calcium is a soft silvery-coloured metal that reacts with other elements to form compounds. In fact, it reacts so easily that it is never found on its own in nature.
If you see calcium metal in a laboratory,
it will often be in the form of small pieces
called pellets. This is to make it easy to use in experiments like the one shown on these pages. With pellets it is possible to demonstrate how calcium reacts with one of the most common compounds of all – water.
 Calcium rapidly reacts with oxygen in the air to form a protective (dull) coating that tends to prevent any further reaction.
It only looks silvery when freshly cut.
 A small pellet of calcium is placed in a beaker of water. To start with it sinks, showing that it is heavier than water.
A test tube filled with
water is placed over the pellet. Notice that bubbles of hydrogen gas
are already rising through the water. This is a result of the reaction of calcium with water.
These calcium pellets look dark because of a surface coating of calcium oxide.
A calcium pellet is placed in a beaker of water and under a test tube.
6 6