Science (English Medium) Class 11 - CBSE Question Bank Solutions

Viruses are non-cellular organisms but replicate themselves once they infect the host cell. To which of the following kingdom do viruses belong to?

A virus is considered as a living organism and an obligate parasite when inside a host cell. But virus is not classified along with bacteria or fungi. What are the characters of virus that are similar to non-living objects?

How are viroids different from viruses?

Difference between Virus and Viroid is ______.

What do the terms phycobiont and mycobiont signify?

Associations between Mycobiont and Phycobiont are found in ______.

What is the basic theme of organisation in the periodic table?

Explain the Formation of a Chemical Bond.

Write Lewis symbols for the following atoms and ions: S and S^2–.

Write Lewis symbols for the following atoms and ions: Al and Al³⁺.

Write Lewis symbols for the following atoms and ions H and H^–.

Use Lewis symbols to show electron transfer between the following atoms to form cations and anions:-

K and S

Use Lewis symbols to show electron transfer between the following atoms to form cations and anions:

Ca and O

Use Lewis symbols to show electron transfer between the following atoms to form cations and anions:

Al and N

A thermodynamic state function is a quantity ______.

For an isolated system, ΔU = 0, what will be ΔS?

What are the common chemical features of alkali metals?

Why are alkali metals not found in nature?

Explain why alkali and alkaline earth metals cannot be obtained by chemical reduction methods?

Why are potassium and cesium, rather than lithium used in photoelectric cells?