(English Medium) ICSE Class 10 - CISCE Important Questions for Chemistry

Choose the correct answer from the options given below:

Ionisation potential increases over a period from left to right because of the

(A) Atomic radius increases and nuclear charge increases

(B) Atomic radius decreases and nuclear charge decreases

(C) Atomic radius increases and nuclear charge decreases

(D) Atomic radius decreases and nuclear charge increases

Choose the correct answer from the options given below:

If an element A belongs to Period 3 and Group II, then it will have

A. 3 shells and 2 valence electrons

B. 2 shells and 3 valence electrons

C. 3 shells and 3 valence electrons

D. 2 shells and 2 valence electrons

Give one word or phrase for the following:

Formation of ions from molecules

The energy released when an electron is added to a neutral gaseous isolated atom to form a negatively charged iron.

A process of formation of ions from molecules which are not in the ionic state

Give a reason for Ionisation potential increases across a period, from left to right

An element in period 3, whose electron affinity is zero:

 Li, K, Na, H (In the decreasing order of their ionization potential) 

F, B, N, O  (In the increasing order of electron affinity) 

Why is the electron affinity of fluorine less than chlorine?

An element with the largest atomic radius among the following is ______.

Give reason for the following:

Ionisation potential decreases down a group.

Arrange the following as per the instruction given in the bracket:

Carbon, Fluorine, Beryllium (decreasing order of atomic size).

Arrange the following as per the instruction given in the bracket:

Potassium, Lithium, Sodium (increasing order of ionization potential).

₁H² is an isotope of hydrogen. In the modern Periodic Table it will ______.

In Period 3 of the Periodic Table, element B is placed to the left of element A. On the basis of this information, choose the correct word from the option to complete the following statement:

The element A would probably have ______ electron affinity than B.

In Period 3 of the Periodic Table, element B is placed to the left of element A. On the basis of this information, choose the correct word from the option to complete the following statement:

The element A would have ______ atomic size than B.

Choose the correct answer from the options given below:

Which of the following is a common characteristic of a covalent compound?

1) high melting point

2) consists of molecules

3) always soluble in water

4) Conducts electricity when it is in the molten state

State the type of bonding in the following molecule.

Water

Identify the term/substance in the following:

The electrons present in the outermost shell of an atom.