Chapter Summary
Metals are lustrous, malleable, and ductile and are good conductors of heat and electricity.
Metals are solids at room temperature, except mercury which is a liquid.
A bond formed by loss or gain of electrons is called ionic bond.
Metals can form positive ions by losing electrons to non-metals.
Metals combine with oxygen to form basic oxides.
But oxides of aluminium and zinc show both acidic and basic properties. So, they are called amphoteric oxides.
A list of common metals arranged in order of their decreasing reactivity is known as reactivity series.
Metals above hydrogen in the reactivity series can displace hydrogen from dilute acids.
A more reactive metal displaces a less reactive metal from its salt solution. Such a reaction is called displacement reaction.
Metals are found in nature as free elements or in the form of their compounds.
Extraction of metals from their ores and then refining them for use is known as metallurgy.
The surface of some metals, such as iron, is corroded when they are exposed to moist air for a long period of time. This phenomenon is known as corrosion.
Rusting of iron is an example of corrosion of metals.
Non-metals are non-malleable and non-ductile.
Non-metals are bad conductors of heat and electricity, except for graphite, which conducts electricity.
Non-metals form negatively charged ions by gaining electrons when they react with metals.
Non-metals form oxides which are either acidic or neutral.
Non-metals do not displace hydrogen from dilute acids. They react with hydrogen to form hydrides.