I assume that we all know what matter is (anything that occupies space and has
mass). Matter is being classified in two ways, physically and chemically.
Matter is classified
physically into its state (solid, liquid and gas), but in this post we are going to focus on the
chemical classification of matter. Matter is classified chemically into : elements, compounds
and mixtures. Let’s start with elements.
What Is An Element ?
An element is a substance which cannot be broken down (decompose) into simpler
units by chemical reactions.
The elements that are recognized are 118 in number, 90 of these
elements occur naturally, while the rest are artificially made. Most of the earth’s crust is made
up of a relatively small number of elements.
Symbols are used to represent elements as they
make it easier for us to write them down and remember them. Elements are arranged according
to their atomic number and are classified into : metals, metalloids and non-metals.
Metals are elements whose atoms ionize by electron loss, the non-metals are elements
whose atom ionize by electron gain, while metalloids are elements that share the properties of
both the metals and the non-metals. The metalloids are also known as “semi-metals”.
of metals are : Tin, calcium, copper, silver, aluminium, gold, lead, iron, zinc, sodium and so many
more, just to name a few popular ones.
Examples of non-metals are : Neon, fluorine, oxygen,
carbon, sulphur, nitrogen, chlorine, argon, etcetera.
Examples of metalloids are : Tellurium,
silicon, arsenic, germanium, antimony, boron, etcetera.
Let’s move to the next chemical
classification of matter (compounds).
What Is A Compound ?
A compound is a substance derived from the chemical union of two or more different
elements. It is a substance that can be decomposed by chemical means into simpler
substances, always in the same ratio by mass. A compound is derived as a result of a chemical
change (chemical reaction). It has different properties from the substances from which it was
derived from. The elements that make up a compound are present in a fixed ratio by mass.
Examples Of Compounds And Their Component Elements:
Calciumtrioxocarbonate(IV)[CaCO3] — Calcium, carbon and oxygen.
Sucrose[C12H22O11] — Carbon, hydrogen and oxygen.
Soap[C17H35COONa] — Carbon, hydrogen, oxygen and sodium.
Water[H2O] — Hydrogen and oxygen.
Aluminumtetraoxosulphate(VI)[Al2(SO4)3] — Aluminium, sulphur and oxygen.
There are so
many compounds known, the ones above are just some of it.
What Is A Mixture ?
A mixture is a substance derived when two or more constituents are physically joined together.
Mixtures are combinations of two or more pure substances in which each substance maintain
its own composition and characteristics.
The components of mixtures can be elements, or
compounds or both, and can be separated by physical means, since they are not chemically
combined. An important characteristic of mixtures is that they can have variable composition.
Mixtures can be further classified into homogeneous mixtures and heterogeneous
Homogeneous mixture is a mixture that is uniform throughout, some good examples
of homogeneous mixtures are : salt and water, air and some alloys.
Heterogeneous mixture on
the other hand is a mixture that is not uniform throughout, some good examples of
heterogeneous mixtures are : salt and charcoal, vegetable soup, foggy air, etcetera.
Examples of some mixtures and their components.
Air – oxygen, carbon(IV)oxide, nitrogen, rare gases (inert gases), dust and moisture.
Urine – urea, mineral salts, water, glucose, etcetera.
Bronze – copper and tin.
Blood – proteins, fat, sugar, oil, mineral salts, water, vitamins, hormones, enzymes, blood cells
Brass – copper and zinc.
Milk – water, fat, sugar, vitamins, proteins and mineral salts.
Palmwine – water, sugar, alkanol, mineral salts, vitamins, yeast, proteins and fat.