Metals and Non-Metals: 18 MCQs with answers

Metals lose electrons; non-metals gain or share electrons.

The root difference is that metals tend to lose electrons to form positive ions, while non-metals tend to gain or share electrons.

Ductility

Ductility is the ability to be drawn into wires, which is why copper is used in wiring.

Mercury

Mercury is the only metal that is liquid at room temperature; most metals are solids.

Graphite

Graphite, a form of carbon, conducts electricity because of delocalised electrons within its layers.

A metal

Lustre, sonority, and malleability are all typical metal properties.

True

Metals conduct electricity because of delocalised (free) electrons, while non-metals generally lack this electron sea and therefore do not conduct.

Good conductivity of heat and electricity

Non-metals are generally poor conductors; good conductivity is a metal property (graphite is a rare exception).

They contain a sea of delocalised free electrons.

The free-electron sea absorbs and re-emits light (lustre) and carries charge and heat (conductivity).

It reacts vigorously with air and moisture.

Sodium is highly reactive and reacts with air and moisture, so kerosene keeps it isolated.

Sulphur — matches and fertilisers

Sulphur and phosphorus are reactive non-metals used in matches and fertilisers.

Silicon

Silicon, germanium, and arsenic are metalloids that show properties of both metals and non-metals.

$\text{Cl} + e^- \rightarrow \text{Cl}^-$

Non-metals gain electrons to form negative ions; chlorine gaining an electron forms chloride ion.

Metals are on the left and centre; non-metals cluster at the top-right.

Metals occupy the left and centre, non-metals cluster at the top-right, and a zig-zag line separates them.

Non-metal

Dullness, brittleness, and poor conductivity are all typical non-metal properties.

Both A and R are true, and R correctly explains A.

Graphite is a non-metal that conducts because of delocalised electrons within its layers, so conductivity alone cannot classify an element as a metal.

Gold is almost inert and does not readily react.

Gold sits low in the reactivity series and is almost inert, so it is found in its pure form.

The element is a non-metal due to its lack of conductivity and dull appearance.

The correct option is B. Non-metals are characterized by being dull, brittle, having low melting points, and poor electrical conductivity. Therefore, the properties of the unknown element align with those of a non-metal.

Sodium loses electrons while chlorine gains electrons, resulting in ionic bonding.

The correct option is C. In this reaction, sodium loses an electron to form a positive ion ($\text{Na}^+$), while chlorine gains an electron to form a negative ion ($\text{Cl}^-$). This transfer of electrons is essential for the formation of ionic bonds in sodium chloride.