Answer: Option A. -> Statement I is true. Statement II is true. Statement II is the correct explanation of statement I.
:
A
The electronic configuration of Li is as follows -
  K
  L
  2
  1
The electron present in L shell experiences less attraction from the nucleus due to the increased distance of the shell. Also, it experiences repulsion from the electrons present in K shell. This further reduces the net effective nuclear force on it.
Hence, it is easier to knock off the outermost electron in lithium as compared to helium.

Answer: Option A. -> Fe is more reactive than hydrogen.
:
A and C
Iron can liberate $H_2$ from dil. $H_2{SO}_4$ but copper cannot liberate $H_2$ from dil. $H_2{SO}_4$. This happens because $Fe$ is more reactive than hydrogen. It can thus displace hydrogen from sulphuric acid and form iron sulphate. Whereas copper is less reactive than hydrogen so, it cannot displace hydrogen from sulphuric acid.

Answer: Option A. -> Strength
:
A, B, and C

Metallic bonding is the cause for many of the properties of metals, such as strength, malleability, ductility, lustre, conduction of heat and electricity.
The sea of electrons and the positive ions in the metal have a strong attractive force between them which is why metals possess high strength.
It is because of the mobile electrons, that metals are good conductors of heat and electricity, as the electrons can move quickly through the body of the metal and pass electricity and heat much faster.

Answer: Option A. -> All ores are minerals.
:
A

The elements or compounds, which occur naturally in the earth’s crust, are known as minerals.

At some places, minerals contain a high percentage of a particular metal and the metal can be profitably extracted from them. These minerals are called ores.

So, all ores are minerals, but not all minerals are ores.

Answer: Option D. -> Bromine
:
D

Oxygen, fluorine are gases, sulphur is a solid at room temperature and bromine is liquid at room temperature.

Answer: Option B. -> ductility
:
B
Ductility is a physical property of matter, usually of metals like gold, silver etc. It is defined as the ability of metals to be drawn into thin wires. Gold is the most malleable and ductile metal among all the metals.

Answer: Option B. -> amphoteric oxides
:
B
Some metal oxides, such as aluminum oxide, zinc oxide, etc., show both acidic as well as basic behavior. Such metal oxides can react with both acids as well as bases to produce salts and water. Metal oxides of this category are known as amphoteric oxides.