Introduction to Atom

Q.

In an oxygen atom, the number of electrons in the valence shell is___.

Q.

What is the mass number and the atomic number of Boron-11?

Q.

Energy of the shells decreases with increase in distance from nucleus.

1. True

2. False

Q.

Why do isotopes have different physical properties?

Q. The electrons present in the outermost shell of an atom are known as

Q. The tendency of atoms to have eight electrons in the outer shell is known as the “octet rule” or “Rule of eight”.

1. True
2. False

Q. Arrange the shells in the order of increasing energy level

1. M Shell
2. N Shell
3. K Shell
4. L Shell

Q.

Which of the following shell is closest to nucleus?

1. K shell

2. L shell

3. N shell

4. M shell

Q. Difference between atomic mass and atomic weight

Q.

Mass of a neutron is more than mass of a proton.

1. False

2. True

Q.

Why and how the valancy of calcium is 2 and why not 0 ?

Q. An electron has a

1. Charge that is opposite and equal to a proton.
2. All of these.
3. Negligible mass.
4. Relative charge of -1.

Q.

An atom having a completely filled outermost shell:

1. Has more combining capacity

2. Has more combining capacity and a valency which is a non-zero number

3. Has a valency which is a non-zero number

4. Shows little chemical activity

Q. A glow was observed near the anode in the cathode ray tube experiment.

1. yellowish
2. reddish
3. greenish

Q.

What are isotopes? Give examples.

Q.

The number of protons and neutrons present in the nucleus of an atom is called its _________.

Q.

The highly ionized gas with equal number of positive and negative charges in which the particles exist in super excited states is called ____________ state.

1. plasma

2. solid

3. liquid

4. gaseous

Q. According to the octet rule an atom can have maximum ______ valence electron in its outermost shell.

1. 8

Q.

An atom is represented by symbol ²³₁₄M. What does number 23 represent?

1. Number of neutrons

2. Mass number

3. Atomic number

4. Number of protons

Q. Isotopes are atoms of different elements, which have different mass numbers.

1. False
2. True

Q.

Complete the following :

Mercury contains 80 protons and 80 electrons and 120 neutrons. Its mass number is ___________.

Q.

23. Define the term isotope with a suitable example.

Q.

How to find the atomic mass of any element?

Q.

Choose the element with correct dot structure?

1. 

2. 

3. 

4. None of the above

Q. Electrons are not accommodated is any given shell until and unless the inner shell is filled

1. True
2. False

Q.

What are radio-isotopes?

Q.

What do you understand by the term ‘isotopes’?

Q.

Name a few common radioactive isotopes.

Q.

Choose the option with correct dot structure.

1. ​

2. ​

3. ​

4. 

Q. Protons and neutron are present inside the nucleus of an atom

1. False
2. True