1. TYPES OF SOLUTIONS
Homogeneous means that the components of the mixture form a single phase. The properties of the
mixture (such as concentration, temperature, and density) can be uniformly distributed through the
volume but only in absence of diffusion phenomena or after their completion. Usually, the substance
present in the greatest amount is considered the solvent. Solvents can be gases, liquids or solids. One or
more components present in the solution other than the solvent are called solutes. The solution has the
same physical state as the solvent.
Gas
Gases dissolve in other gases, as we experience in air. Nitrogen, which is about 80% of the mixture, is
considered the solvent. Here we have a gaseous solution.
If the solvent is a gas, only gases are dissolved under a given set of conditions. An example of a gaseous
solution is air (oxygen and other gases dissolved in nitrogen). Since interactions between molecules play
almost no role, dilute gases form rather trivial solutions. In part of the literature, they are not even
classified as solutions, but addressed as mixtures.
Liquid
If the solvent is a liquid, then gases, liquids, and solids can be dissolved. Here are some examples:
Gas in liquid:
o Oxygen in water
o Carbon dioxide in water – a less simple example, because the solution is accompanied by
a chemical reaction (formation of ions). Note also that the visible bubbles in carbonated
water are not the dissolved gas, but only an effervescence of carbon dioxide that has
come out of solution; the dissolved gas itself is not visible since it is dissolved on a
molecular level.
Liquid in liquid:
o The mixing of two or more substances of the same chemistry but different concentrations
to form a constant. (Homogenization of solutions)
o Alcoholic beverages are basically solutions of ethanol in water.
Solid in liquid:
o Sucrose (table sugar) in water
o Sodium chloride (table salt) or any other salt in water, which forms an electrolyte: When
dissolving, salt dissociates into ions.
Counterexamples are provided by liquid mixtures that are not homogeneous: colloids, suspensions,
emulsions are not considered solutions.
Body fluids are examples for complex liquid solutions, containing many solutes. Many of these are
electrolytes, since they contain solute ions, such as potassium. Furthermore, they contain solute molecules
like sugar and urea. Oxygen and carbon dioxide are also essential components of blood chemistry, where
significant changes in their concentrations may be a sign of severe illness or injury.
Solid
If the solvent is a solid, then gases, liquids and solids can be dissolved.
Gas in solids:

2. o Hydrogen dissolves rather well in metals, especially in palladium; this is studied as a
means of hydrogen storage.
Liquid in solid:
o Mercury in gold, forming an amalgam
o Hexane in paraffin wax
Solid in solid:
o Steel, basically a solution of carbon atoms in a crystalline matrix of iron atoms.
o Alloys like bronze and many others.
o Polymers containing plasticizers.
Metal
A metal (from Greek "μέταλλον" – métallon, "mine, quarry, metal"[1][2]
) is an element, compound, or
alloy that is a good conductor of both electricity and heat. Metals are usually shiny, malleable and
ductile.[3]
The meaning of the term "metal" differs for various communities (for example, astronomers call
for convenience metals everything but hydrogen and helium,[4]
see Metallicity). Many elements and
compounds that are not normally classified as metals become metallic under high pressures.
Nonmetal
Nonmetal, or non-metal, is a term used in chemistry when classifying the chemical elements. On the
basis of their general physical and chemical properties, every element in the periodic table can be termed
either a metal or a nonmetal. (A few elements with intermediate properties are referred to as metalloids.)
The elements generally regarded as nonmetals are:
In Group 1: hydrogen (H) (The only nonmetal in this group)
In Group 14: carbon (C) (Again, the only nonmetal in this group)
In Group 15: (the pnictogens): nitrogen (N), phosphorus (P)
In Group 16: (the chalcogens): oxygen (O), sulfur (S), selenium (Se)
In Group 17: (the halogens): fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At)
All elements (with the possible exception of ununoctium) in Group 18 – the noble gases
There is no rigorous definition for the term "nonmetal" – it covers a general spectrum of behaviour.
Common properties considered characteristic of a nonmetal include:
poor conductors of heat and electricity when compared to metals
they form acidic oxides (whereas metals generally form basic oxides)
in solid form, they are dull and brittle, rather than metals which are lustrous, ductile or malleable
usually have lower densities than metals
they have significantly lower melting points and boiling points than metals (with the exception of
carbon)
non-metals have high electronegativity
Only eighteen elements in the periodic table are generally considered nonmetals, compared to over eighty
metals, but nonmetals make up most of the crust, atmosphere and oceans of the earth. Bulk tissues of
living organisms are composed almost entirely of nonmetals. Most nonmetals are monatomic noble gases
or form diatomic molecules in their elemental state, unlike metals which (in their elemental state) do not
form molecules at all.

3. EXAMPLES OF METALS
ZINC
CADMIUM
SCANDIUM
TITANIUM
CHROMIUM
MANGANESE
IRON
NICKEL
YTTRIUM

4. EXAMPLES OF NON METALS
HELIUM
HYDROGEN
NITROGEN
CARBON
BORON
OXYGEN
FLOURINE