ICSE ICSE Class 8 - CISCE Question Bank Solutions for Chemistry

Explain the rule with example according to which electrons are filled in various energy levels

What are the two main parts of which an atom is made of?

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Gases become good conductors of electricity under ........ (low/high) pressure and .............. (low/high) voltage electrical discharge.

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The electrons revolving in shells close to the nucleus are called ................... electrons.

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In an atom, the last shell containing electrons is called its..................shell.

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The γ-rays are............................ radiations, like light.

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Which of the following scientists observed that cathode rays consists of negatively charged particles?

1. John Dalton
2. J J Thomson
3. James Chadwick
4. Democritus

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In 1908, R A Millikan found the charge of an electron to be

1. 1.6 x 10^-19 C
2. 1.6 x 10^-15 C
3. 1.4 x 10^-19 C
4. 1.6 x 19^-16 C.

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How many times is a proton heavier than an electron?

1. 1500
2. 1800
3. 1840
4. none of these

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β-particles are actually a stream of

1. protons
2. electrons
3. neutrons
4. none of these

TRUE \ FALSE

Electrons are present in the nucleus.

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What is an atom?

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Describe a discharge tube.

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What do you mean by electron transition?

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Name the isotopes of hydrogen.

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What is the charge on a neutron ?

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What is the number of neutrons present in a potassium atom ?

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Name the three subatomic particles. How are they different from each other ?

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What is the maximum number of electrons that L shell can accommodate ? Give reasons for your answer.

Draw the electronic configuration of the following elements clearly stating the number of neutrons and protons in their nucleus.
a. Beryllium b. Silicon
c. Chlorine d. Aluminium
e. Nitrogen