Bonding In Metal Carbonyls

Among the given options, Chlorine is the non-metal. Chlorine is a halogen and is known for its chemical reactivity, typically forming salts like sodium chloride when combined with metals.

Potassium, Sodium, and Silicon are metals or metalloids. Potassium and sodium are alkali metals, and silicon is a metalloid, exhibiting both metallic and non-metallic properties.

The correct option is (B): Chlorine

When a metal reacts with sodium hydroxide (NaOH), hydrogen gas ( ) is released. Among the given metals:
Zinc (Zn) reacts with sodium hydroxide to form sodium zincate and liberates hydrogen gas:
Calcium (Ca) and Magnesium (Mg) also react with NaOH but they are less commonly referred to in typical reactions where hydrogen gas is liberally produced in similar contexts.
Sodium (Na) is an alkali metal and reacts very vigorously with water to produce hydrogen gas, but in this case, Na reacts with water, not NaOH specifically.

Thus, the correct answer is Zinc (Zn).The correct option is (A): Zn

Lead (Pb) does not react with water, either cold or hot, under normal conditions.
Sodium (Na) and Potassium (K) react vigorously with both cold water and steam, producing hydrogen gas.
Iron (Fe) reacts with steam but not with cold water. This is because iron reacts with steam at high temperatures to form iron oxide and hydrogen gas: However, it does not react significantly with cold water. Thus, the metal that liberates on reaction with steam but not with cold water is Iron (Fe).

The correct option is (C):

The melting points of compounds generally follow this order:

Ionic compounds typically have the highest melting points due to the strong electrostatic forces between the oppositely charged ions.

Polar covalent compounds have intermediate melting points, as the molecules are attracted by dipole-dipole interactions, which are weaker than ionic bonds.

Non-polar covalent compounds usually have the lowest melting points because the forces between their molecules are relatively weak (London dispersion forces). Thus, the correct order is:

The correct option is (B): lonic > polar covalent > non-polar covalent

The nitrogen molecule (N₂) is a diatomic molecule consisting of two nitrogen atoms. To understand the bonding, consider the electronic configuration of a nitrogen atom, which is 1s² 2s² 2p³. Each nitrogen has five valence electrons.

When two nitrogen atoms form a molecule, they share three pairs of electrons to complete their octets, forming a triple bond. This triple bond comprises:

• One sigma (σ) bond: This bond is formed by the head-on overlap of two sp orbitals (or in some texts, p-orbitals) from each nitrogen atom.
• Two pi (π) bonds: These bonds are formed by the side-by-side overlap of the remaining unhybridized p orbitals from each nitrogen atom.

Therefore, the correct type of bonds in a nitrogen molecule is one sigma (σ) bond and two pi (π) bonds.

In conclusion, the bonds present in a nitrogen molecule are categorized as 1σ and 2π.