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

Explain any two environmental impacts of an ‘oil spill’.

State the importance of water for all general uses.

Give the influence of pressure.

Copy and complete the following table relating to the atomic structure of some elements:

Select the correct word from the words in option to complete the sentence:

If pressure on the surface of water increases its boiling point ____ and freezing point ____.

Select the correct word from the words in option to complete the sentence:

Dissolved air in water contains a ____ percentage of oxygen than ordinary air.

Give a reason for the following:

Efflorescence is minimum during humid conditions.

Give a reason for the following:

A crusty ‘boiler scale’ is formed in boilers, when hard water is used.

Name or state the following:

A deliquescent salt of a trivalent metal.

Differentiate between the following:

Natural water and treated water

Draw the geometric atomic structure of the three isotopes of hydrogen and the two isotopes of chlorine.

Match the terms in List I with the correct answers in List II.

Draw the geometric atomic structure of the following atom showing the number of electrons, protons and neutrons in them:

\[\ce{^12_6C}\]

Draw the geometric atomic structure of the following atom showing the number of electrons, protons and neutrons in them:

\[\ce{^23_11Na}\]

Draw the geometric atomic structure of the following atom showing the number of electrons, protons and neutrons in them:

\[\ce{^31_15P}\]

Draw the geometric atomic structure of the following atom showing the number of electrons, protons and neutrons in them:

\[\ce{^39_19K}\]

Draw the geometric atomic structure of the following atom showing the number of electrons, protons and neutrons in them:

\[\ce{^40_20Ca}\]

Give a reason why elements need to be properly classified.

How did the early chemists classify elements?

Why was this basis of classification discarded for future classification of elements?