(English Medium) ICSE Class 9 - CISCE Question Bank Solutions for Chemistry

Give an example of a reaction where the following is involved .

Absorption of heat

Give an example of a reaction where the following is involved .

High pressure is required

State the modern periodic law.

How many periods and groups are there in the modern periodic table?

What is meant in the periodic table by a period?

From the standpoint of atomic structure, what determines which elements will be the first and which the last in a period of the periodic table?

What is the number of elements in the 1^st period?

What is the number of elements in the 3^rd period, of the modern periodic table?

How does number of (i) valence electrons (ii) valency; vary on moving from left to right in the second period of a periodic table?

Name and state the following with reference to the elements of the first three periods of the periodic table.

A covalent compound formed by an element in period 2 and a halogen.

Name an element of group 18 which can form compounds.

The horizontal rows in a periodic table are called _____.

An element A has 2 electrons in its fourth shell. State its electronic configuration.

In what respect does hydrogen differ from:

halogens? 

Compare hydrogen and halogens on the basis of:

physical state

Two elements P and Q belong to the same period of the modern periodic table and are in group 1 and group 2, respectively. Compare the following characteristics in the tabular form.

1. Number of electrons in their atoms
2. Their tendency to lose electrons
3. Their metallic characters
4. Formation of their oxides
5. Formulae of their chlorides

State (i) the three variables for gas laws and (ii) SI units of these variables.

Give reason for the following:

Gases have a lower density compared to solids or liquids.

Give reason for the following:

Gases exert pressure in all directions.

What is meant by aqueous tension? How is the pressure exerted by a gas corrected to account for aqueous tension?