α <  β <  γ ray.

OR

Fusion reaction is the source of the sun’s energy.

An ionic bond is present in CaO.

Silver (Ag) is used as the cathode to electroplate silver over a copper spoon.

OR

Acetic acid (CH₃COOH).

The electrode connected to the negative terminal of the battery is called a cathode.

One use of liquid ammonia is as a refrigerant in refrigeration systems.

OR

The formula of the precipitate formed when aqueous ammonia is added to an aqueous solution of aluminium chloride is Al(OH)₃ (aluminium hydroxide).

In the laboratory preparation of nitrogen, an aqueous solution of Sodium Nitrite (NaNO₃) is mixed with an aqueous solution of ammonium chloride and heated.

Propanal or Propan-1-al.

OR

The structural formula of the positional isomer of CH₃CH₂CH₂OH (1-propanol) is CH₃CH(OH)CH₃ (2-propanol).

Used as a coating in non-stick cookware due to its hydrophobic and high heat-resistant properties.

Methane hydrate is a solid compound consisting of methane molecules trapped within a lattice of ice-like water molecules.

P₂ = 2P1, V₂ = V₁/2, T₁ = 273 K

From the combined gas equation : P_1V_1\\over T_1=P_2V_2\\over T_2

or, P_1V_1\\over 273=2P_1V_1\\over 2 × T_2

T₂ = 273 K

∴ Final temperature (T₂) = O ºC

OR

Initial Temperature (T₁) = 273 K,

Final Temperature (T₂) = 273 + 546 = 819 K

From Charle\'s Law: V_1\\over T_1=V_2\\over T_2

⇒ V_1\\over 273=V_2\\over 819

⇒ V_2\\over V_1=819\\over 273

⇒ V₂ : V₁ = 3 : 1

If a ray of light passes through a Convex lens such that the direction of the emergent rays is parallel to the direction of the incident rays, then the path of the ray of light inside the lens intersects the principal axis at a particular point. This point is called the optical centre of the convex lens.

OR

The Earth's sky appears blue during the daytime because blue light from the Sun is scattered more than other colours due to its shorter wavelength. This scattering causes the sky to look predominantly blue to our eyes.