Questions

Based on conventionality in deriving energy, energy sources could be classified as

Conventional ::

coal, oil, hydro, nuclear, etc... sources which can be used up or exhaustible.

(and)

Non - conventional ::

solar, wind, tidal, geothermal, biogas, etc... sources which are not exhausted.

Among the given options, Geothermal energy is the alternative energy source among all the choices that are given in the question, that is exhaustible.

Many types of renewable energy resources such as wind and solar energy are constantly replenished and will never run out.

Molecular compounds are those with covalent bonds between the elements and those elements are typically non metals.

Here in the given options, Ar is an element. NaI has an ionic bond. Hence, N2O4 has a covalent bond between the two non metals and is a molecular compound.

Carbohydrates are also called as saccharides are molecular compounds made from just three elements:

carbon, hydrogen and oxygen.

Carbohydrates are:

* a source of energy for the body e.g. glucose and a store of energy, e.g. starch in plants

* building blocks for polysaccharides (giant carbohydrates), e.g. cellulose in plants and glycogen in the human body

* components of other molecules eg DNA, RNA, glycolipids, glycoproteins, ATP

Types:

1. Monosaccharides (e.g. glucose) and

2. Disaccharides (e.g. sucrose) are relatively small molecules. They are often called sugars.

3. Other carbohydrate molecules are very large called Polysaccharides such as starch and cellulose.