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

If electrons are getting added to en element Y; then

What charge will Y migrate to during the process of electrolysis?

Explain the following:

Atoms combine by transfer and sharing of an electron(s).

Choose the correct answer from A, B, C and D:

When a metal atom becomes an ion:

The electronic configuration of nitrogen is (2, 5). How many electrons in the outer shell of a nitrogen atom are not involved in the formation of a nitrogen molecule?

What is the term defined below?

A bond formed by a shared pair of electrons, each bonding atom contributing one electron to the pair.

Name or state the following:

A bond formed by transfer of electron(s)

Name or state the following:

Ion formed by the gain of an electron(s)

An element X has 2 electrons in its M shell, it forms a bond with an element Y which has 7 electrons in its third orbit.

1. Write the formula of the compound formed.
2. Which nearest inert gas electronic configuration will element X and Y acquire.
3. Show by orbital diagram the formation of the compound between X and Y. 

In the formation of (i) oxygen molecule (ii) carbon tetrachloride molecule, state the following:

1. Electronic configuration of nearest inert gas attained.
2. How many electrons are shared/transferred in bond formation
3. Which type of bonds these compounds form?
4. Draw their orbital diagrams. 

How does number of valence electrons vary on moving from left to right in the third period of a periodic table?

Sodium and aluminum have atomic numbers 11 and 13, respectively. They are separated by one element in the periodic table and have valencies 1 and 3 respectively. Chlorine and potassium are also separated by one element in the periodic table (their atomic numbers being 17 and 19, respectively) and yet both have valency 1. Explain.

Name the impurities present in hydrogen prepared in the laboratory.

Name the impurities present in hydrogen prepared in the laboratory.

How can these impurities be removed? 

How can these impurities be removed? 

Under what conditions can hydrogen be made to combine with chlorine?

Name the products and write the equation for the reaction.

Under what conditions can hydrogen be made to combine with chlorine?

Name the products and write the equation for the reaction.

Give reason:

Apparatus for laboratory preparation of hydrogen should be airtight and away from a naked flame.

Give reason:

Apparatus for laboratory preparation of hydrogen should be airtight and away from a naked flame.

Correct the following statement:

The boiling point of water is 273 K.