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Science

Exercise 9 - Metals and Non-Metals

The characteristics of both metals and non-metals are listed below. Try and learn all the characteristics since this is a very popular subject for exams.



Metals

Three-quarters of the periodic table are metals.
Metals are very good conductors of both heat and electricity.
Metals have both high melting and boiling points.
All metals are solid except mercury, which is liquid at room temperature.
Metals are strong and dense.
Metals are also malleable (capable of being shaped, normally by hammer) and ductile (capable of being drawn into wires).
Metals are sonorous (they ping when hit).
Metals are shiny (when new or freshly cut).
Some metals are magnetic (for example, iron and steel).
Metals can be mixed together to form alloys.
Metal Oxides dissolve in water to form alkaline solutions.

Unusual Metals

There are some metals, which have unusual properties and behave differently to the majority of metals.

Mercury

Mercury is the only metal that is a liquid at room temperature. All other metals are solid at room temperature. Mercury is used in thermometers to measure temperature since it is a liquid and expands more than solids.

Sodium

Sodium reacts very differently to other metals.
Most metals have a very high density; Sodium has a low density and can even float on water.
Most metals are hard and strong but Sodium is soft and can actually be cut with a knife.
Most metals react slowly or not at all with water whereas sodium reacts vigorously with water giving off hydrogen (a gas) and forming sodium hydroxide (an alkaline solution).

It is important to note that metals Potassium and Lithium react in a similar way to sodium.


Non-Metals

Only 21 elements of the periodic table are non-metal.
Non-metals have both low boiling and melting points.
Non-metals are not ductile, malleable or sonorous.
Non-metals tend to be brittle and can break easily.
Non-metals tend to be dull and not shiny.
Non-metals have low densities.
Non-metals are poor conductors of heat and electricity.
Non-metal Oxides dissolve in water to form acidic solutions.
There is only one non-metal that is liquid at room temperature - bromine.
There are 11 non-metals that are gases at room temperature.

Unusual Non-Metals

Carbon

Carbon can exist in two forms; diamond or graphite.

Diamond is a very strong substance due to all the carbon elements being held together by very strong bonds. Most non-metals are soft or brittle - diamond is very hard.
Most non-metals have low melting points- -diamond has a very high melting point - over 3500 °C.

Graphite

Graphite is also a form of carbon. It consists of the same carbon atoms as diamond but the bonding between atoms is layered.
Most non-metals do not conduct electricity but graphite is unusual because it can conduct electricity.

Bromine

Bromine is the only non-metal that is a liquid at room temperature.


Metals and Non-metals: Questions

Exercise: << 1 2 3 4 5 6 8 9