2. • Malleability: Metals have the ability to withstand hammering and can be made into thin
sheets known as foils.
• Ductility: Metals can be drawn into wires. 100 gm of silver can be drawn into a thin wire
about 200 meters long.
• Hardness: All metals are hard except sodium and potassium, which are soft and can be
cut with a knife.
• Valency: Metals have 1 to 3 electrons in the outermost shell of their atoms.
• Conduction: Metals are good conductors because they have free electrons. Silver and
copper are the two best conductors of heat and electricity. Lead is the poorest conductor
of heat. Bismuth, mercury and iron are also poor conductors.
• Density: Metals have high density and are very heavy. Iridium and osmium have the
highest densities where as lithium has the lowest density.
• Melting and Boiling point: Metals have high melting and boiling point. Tungsten has
the highest melting point where as silver has low boiling point. Sodium and potassium
have low melting points.
3. PHYSICAL PROPERTIES OF METALS
• Physical State: Metals are solids at room temperature with the
exception of mercury and gallium, which are liquids at room
temperature.
• Lustre: Metals have the quality of reflecting light from its surface and
can be polished e.g., gold, silver and copper.
4. • Metals in general have high electrical conductivity, high thermal conductivity,
and high density. Typically they are malleable and ductile, deforming under
stress without cleaving.[6] In terms of optical properties, metals are shiny
and lustrous. Sheets of metal beyond a few micrometres in thickness appear
opaque, but gold leaf transmits green light. Metals are sonorous i.e. they
produce sound.
• Although most metals have higher densities than most nonmetals,[6] there is
wide variation in their densities, Lithium being the least dense solid element
and osmium the densest. The alkali and alkaline earth metals in groups I A
and II A are referred to as the light metalsbecause they have low density, low
hardness, and low melting points.[6] The high density of most metals is due
to the tightly packed crystal lattice of the metallic structure. The strength of
metallic bonds for different metals reaches a maximum around the center of
thetransition metal series, as those elements have large amounts of
delocalized electrons in tight binding type metallic bonds. However, other
factors (such as atomic radius, nuclear charge, number of bonds orbitals,
overlap of orbital energies and crystal form) are involved as well.[6]
5.
6. USES OF NON METALS
• Physical state: Most of the non-metals exist in two of the three states of matter at
room temperature: gases (oxygen) and solids (carbon). These have no metallic
lustre, and do not reflect light.
• Nature: Non-metals are very brittle, and cannot be rolled into wires or pounded into
sheets.
• Conduction: They are poor conductors of heat and electricity.
• Electronegative Character: Non-metals have a tendency to gain or share electrons
with other atoms. They are electronegative in character.
• Reactivity: They generally form acidic or neutral oxides with oxygen
7.
8. QUIZ
• Which element has high melting point?
• Tungsten
• Which element has low melting point?
• Silver
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