ICSE ICSE Class 7 - CISCE Question Bank Solutions

A certain particle ‘X’ has 17 protons, 18 electrons and 20 neutrons.

What is the charge on the particle ?

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If an atom gains an electron, it is called an _______

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If an atom loses an electron, it acquires ______ a charge.

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A charged particle is called an _____

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An _______ is electrically neutral.

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An excess of electrons produces a ________ charge.

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A deficiency of electrons produces a ________ charge.

Elements X and Y have 1 and 7 electrons in their outermost shell respectively.

Which element will lose electron?

Elements X and Y have 1 and 7 electrons in their outermost shell respectively.

Which element will gain electron?

Elements X and Y have 1 and 7 electrons in their outermost shell respectively.

Which will form positive ion?

Elements X and Y have 1 and 7 electrons in their outermost shell respectively.

Which will form negative ion?

Elements X and Y have 1 and 7 electrons in their outermost shell respectively.

What will be the charge present of the molecule XY after chemical combination?

What is the number of electrons donated by a magnesium atom and number of electrons accepted by a sulphur atom during their chemical combination?

How many units of charge are developed on each atom?

What is the number of electrons after the transfer of electrons in magnesium and sulphur atoms.

Diagrammatically represent the transfer of electrons.

Write the molecular formulae of Magnesium nitride:

State the meaning of the term – (a) atom, (b) molecule, (c) radical – with a suitable example.

Draw the basic structure of an atom representing its –

1. Subatomic particles
2. Nucleus
3. Orbits or shells.

‘Atoms of the same element or different from Dalton’s atomic theory by the Modern Atomic Theory.
Give two examples each of –

• Atoms of the same element
• Atoms of different elements combining to form a molecule.