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

An atom X has 2, 8, 7 electrons in its shell. It combines with Y having 1 electron in its outermost shell.

Write the formula of the compound formed. 

Lithium, sodium, and potassium elements were put in one group on the basis of their similar properties. What are those similar properties?

What is the colour of the flame of sodium and potassium?

How the reaction can proceed continuously? 

Calculate the molecular mass of the following:

Na₂SO₄.10H₂O

Given atomic mass of Cu = 63·5, H = 1, O = 16, C = 12, N = 14, Mg = 24, S = 32

Define the term of the electron.

The atom of aluminium is represented by ²⁷Al₁₃. Write down the number of electrons in the different orbits or shells in one atom of aluminium.

The atom of aluminium is represented by ²⁷Al₁₃. Write down the number of protons in the different orbits or shells in one atom of aluminium.

The atom of aluminium is represented by ²⁷Al₁₃. Write down the number of neutrons in the different orbits or shells in one atom of aluminium.

The atom of aluminium is represented by ²⁷Al₁₃. Write down the number of the arrangement of electrons in the different orbits or shells in one atom of aluminium.

What is meant by the term orbits

What are ‘energy levels’?

Explain the arrangement and distribution of electrons in the various shells with reference to an atom in general and to an atom of potassium ‘³⁹₁₉K’ with special reference to the 2n² rule.

Differentiate between the term Stable and unstable electronic configuration.

Differentiate between the term Duplet and octet rule.

The following element is given \[\ce{_3U}\]. State the electronic configuration and state whether it is a metal, non-metal, or inert gas.

The following element is given \[\ce{_6V}\]. State the electronic configuration and state whether it is a metal, non-metal, or inert gas.

The following element is given \[\ce{_9W}\]. State the electronic configuration and state whether it is a metal, non-metal, or inert gas.

The following element is given \[\ce{_14X}\]. State the electronic configuration and state whether it is a metal, non-metal, or inert gas.

The following element is given \[\ce{_18Y}\]. State the electronic configuration and state whether it is a metal, non-metal, or inert gas.