Chemical substance facts for kids
A chemical substance is any material with a known chemical composition. For example, water has the same properties and the same ratio of hydrogen to oxygen whether it came from a river or was made in a laboratory. Typical chemical substances found in the home include water, salt (sodium chloride) and bleach. Generally, substances exist as a solid, a liquid, or a gas, and may change between these phases of matter when there are changes in temperature or pressure.
An element is a chemical substance that is made up of a particular kind of atom and hence cannot be broken down or transformed by a chemical reaction into a different element, though it can be transmutated into another element through a nuclear reaction. This is so, because all of the atoms in a sample of an element have the same number of protons, though they may be different isotopes, with differing numbers of neutrons.
As of 2012, there are 118 known elements, about 80 of which are stable – that is, they do not change by radioactive decay into other elements.
Images for kids
Cranberry glass, while appearing homogeneous, is a mixture consisting of glass and gold colloidal particles of about 40 nm in diameter, giving it a red color.
Chemical substance Facts for Kids. Kiddle Encyclopedia.