Rutherford's Model of an Atom

Q.

Describe Rutherfords scattering experiment.

Q.

Name the three sub-atomic particles of an atom.

Q.

Differentiate between proton and electron.

Q.

In scattering, the impact parameter $b$ is defined as the:

Q.

How and why electrons revolve around the nucleus?

Q.

An atom of an element has 11 protons, 11 electrons and 12 neutrons. What is the the atomic mass?

Q.

Who is known as the 'Father' of nuclear physics?

1. Rutherford

2. J.J. Thomson

3. John Dalton

4. E. Goldstein

Q.

The mass of an electron is approximately 1/2000 times that of:

1. Proton

2. Beta particle

3. Alpha particle

4. Neutron

Q. Rutherford's model failed to explain the of the atom.

1. stability
2. divisibility
3. neutrality

Q.

In Rutherfords experiment, generally, the thin foil of heavy atoms, like gold, platinum, etc. have been used to be bombarded by the $\mathrm{\alpha }$-particles. If the thin foil of light atoms like aluminum etc. is used, what difference would be observed from the above results?

Q.

An atom containing 11 protons and 12 neutrons has mass number equal to 23. . True or False

1. True

2. False

Q.

Why does an atom have no net electric charge?

1. Its subatomic particles carry no electrical charge.

2. The positively charged protons cancel out the negatively charged electrons.

3. The positively charged protons cancel out the negatively charged neutrons.

Q.

Alpha particles are represented as:

1. He⁺²

2. He⁺

3. He

4. He^-2

Q.

What were the results of Rutherfords model of an atom?

Q.

Explain the following.

The mass of an atom is concentrated inside the nucleus of an atom.

Q. Question 18
Atomic models have been improved over the years. Arrange the following atomic models in the order of their chronological order.
(i) Rutherford's atomic model
(ii) Thomson's atomic model
(iii) Bohr's atomic model

(a) (i), (ii) and (iii)
(b) (ii), (iii) and (i)
(c) (ii), (i) and (iii)
(d) (iii), (ii) and (i)

Q. Thomson proposed that the nucleus of an atom contains protons and neutrons.

1. True
2. False

Q.

Which of the following is not a part of the observations made by Rutherford in his experiment?

1. Very few alpha particles deflected at small angles.

2. Very few alpha particles deflected at small angles.

3. Only a few alpha particles rebound completely and turn back on their path

4. Most alpha particles passed straight through gold foil.

Q.

What observations in the scattering experiment led Rutherford to make the following conclusions:

The nucleus has a positive charge.

Q. Rutherford used alpha particles in his experiment. The charge of alpha particles is _________.

1. 2
2. -1
3. -2
4. 4

Q. Statement 1 (S1): To overcome the drawbacks of Rutherford’s atomic model, Bohr suggested that electrons revolve around the nucleus in certain discrete orbits.
Statement 2 (S2): According to Bohr, the electrons do not radiate energy while revolving in discrete orbits.

Q.

The charge of an atom is___.

1. Electrically neutral

2. Negatively charged

3. Positively charged

4. None of these

Q.

Question 1

Specify the charge carried by anions? What happens to an atom ‘A’ if its atom gains two electrons?

Q.

Justify: "An atom on the whole is an electri­cally neutral entity".

Q.

1 carat of diamond is equal to 500 mg or 0.5 g.

1. True
2. False

Q. Question 5
Compare all the proposed models of an atom given in this chapter.

Q.

1. True
2. False

Q.

The mass of an electron is approximately 1/2000 times that of a/an :

1. Alpha particle

2. Beta particle

3. Proton

4. Atom

Q. Question 5
Which of the following statements about Rutherford's model of atom are correct?
(i) Considered the nucleus as positively charged.
(ii) Established that the a-particles are four times as heavy as a hydrogen atom.
(iii) Can be compared to solar system.
(iv) Was in agreement with Thomson's model.

(a) (i) and (iii)
(b) (ii) and (iii)
(c) (i) and (iv)
(d) only (i)

Q.

Why do electrons return to ground state ?