Explanation

The mass of a nucleus is always less than the sum of the masses of its constituent nucleons.

This difference in mass is known as the "mass defect".

When nucleons come together to form a nucleus, they release energy in the form of binding energy.

According to Einstein's famous equation E=mc², this energy released corresponds to a decrease in mass. 

Explanation

Coal can be converted to petroleum through the Fischer-Tropsch process. 

The Fischer-Tropsch process is a series of chemical reactions

That converts carbon monoxide and hydrogen (syngas) into liquid hydrocarbons, which can be used as a substitute for petroleum. 

Explanation

The ozone layer is a region within the stratosphere, extending from about 15 to 30 km (9 to 19 miles) above the Earth's surface.

It contains a high concentration of ozone (O3), a molecule made up of three oxygen atoms. 

The ozone layer plays a crucial role in protecting the Earth from harmful ultraviolet (UV) radiation from the sun, particularly UV-C and UV-B rays.

Explanation

• A solution that contains a solid solute dissolved in a liquid solvent is called a solid-in-liquid solution or a solute-solvent solution.
• This is the most common type of solution, where a solid substance (the solute) is dissolved in a liquid substance (the solvent).

Explanation

• At room temperature, most ionic compounds are crystalline solids, meaning they have a rigid and orderly crystal structure.
• This is because the strong electrostatic forces between the oppositely charged ions hold them in a fixed position, creating a three-dimensional lattice.

Explanation

• Electronegativity is the ability of an atom to attract a shared pair of electrons in a covalent bond.
• It measures the ability of an atom to pull electrons towards itself.

Explanation

Air is a mix of gases, with nitrogen (78%) and oxygen (21%) being the main components.

The plus trace amounts of other gases like argon, carbon dioxide, and water vapor.

Explanation

1-Butyne is an alkyne, and the hydrogen atom attached to the triple-bonded carbon is relatively acidic due to the high s-character of the carbon involved in the triple bond.

This allows it to donate a proton (H+) in an acid-base reaction. 

Explanation

Anthracite is the hardest and most mature form of coal, containing the highest percentage of carbon (about 86–98%).

It burns cleanly with very little smoke.

It has the highest energy content among coal types.

Explanation

N2 (Nitrogen) has the highest critical temperature among the options (Helium - He and Hydrogen - H). 

Nitrogen (N2): While still lower than many other substances

It has a higher critical temperature than Helium because of stronger intermolecular forces.