Default Title

Question (1)

QN0026386

An atom of an element has 17 protons, 18 neutrons and 17 electrons. What is its mass number?

(A) 17
(B) 18
(C) 35
(D) 34

Correct Answer: C

Explanation:

Mass number = Protons + Neutrons = 17 + 18 = 35

Link:

Report Error

Question (2)

QN0026387

Which of the following pairs represents isotopes?

(A) Carbon-12 and Nitrogen-12
(B) Chlorine-35 and Chlorine-37
(C) Sodium-23 and Magnesium-24
(D) Oxygen-16 and Sulphur-16

Correct Answer: B

Explanation:

Isotopes have same atomic number but different mass numbers.

Link:

Report Error

Question (3)

QN0026388

An atom contains 13 protons and 10 electrons. The particle formed will be —

(A) Neutral atom
(B) Negatively charged ion
(C) Positively charged ion
(D) Neutron

Correct Answer: C

Explanation:

Protons are more than electrons by 3.

Link:

Report Error

Question (4)

QN0026389

Which scientist discovered the nucleus through alpha particle scattering experiment?

(A) Dalton
(B) Bohr
(C) Rutherford
(D) Chadwick

Correct Answer: C

Explanation:

Rutherford explained the nuclear structure of atom.

Link:

Report Error

Question (5)

QN0026390

The electronic configuration of an atom is 2, 8, 7. What is its valency?

(A) 7
(B) 0
(C) 2
(D) 1

Correct Answer: D

Explanation:

It requires 1 electron to complete octet.

Link:

Report Error

Question (6)

QN0026391

The atomic number of an element is 15. How many electrons are present in its outermost shell?

(A) 2
(B) 5
(C) 8
(D) 15

Correct Answer: B

Explanation:

Electronic configuration = 2, 8, 5

Link:

Report Error

Question (7)

QN0026392

Which subatomic particle contributes negligibly to atomic mass?

(A) Proton
(B) Neutron
(C) Electron
(D) Nucleus

Correct Answer: C

Explanation:

Link:

Report Error

Question (8)

QN0026393

An atom has mass number 40 and contains 22 neutrons. Find its atomic number.

(A) 18
(B) 22
(C) 40
(D) 62

Correct Answer: A

Explanation:

Atomic number = Mass number − Neutrons = 40 − 22

Link:

Report Error

Question (9)

QN0026394

Which of the following electronic configurations represents a noble gas?

(A) 2, 8, 1
(B) 2, 8, 7
(C) 2, 8, 8
(D) 2, 6

Correct Answer: C

Explanation:

Noble gases have completely filled outer shells.

Link:

Report Error

Question (10)

QN0026395

An atom has 20 protons and 20 neutrons. Which statement is correct?

(A) Atomic number = 40
(B) Mass number = 20
(C) Mass number = 40
(D) Valency = 0

Correct Answer: C

Explanation:

Mass number = 20 + 20

Link:

Report Error

Question (1)

An atom of an element has 17 protons, 18 neutrons and 17 electrons. What is its mass number?

Explanation:

Link:

Question (2)

Which of the following pairs represents isotopes?

Explanation:

Link:

Question (3)

An atom contains 13 protons and 10 electrons. The particle formed will be —

Explanation:

Link:

Question (4)

Which scientist discovered the nucleus through alpha particle scattering experiment?

Explanation:

Link:

Question (5)

The electronic configuration of an atom is 2, 8, 7. What is its valency?

Explanation:

Link:

Question (6)

The atomic number of an element is 15. How many electrons are present in its outermost shell?

Explanation:

Link:

Question (7)

Which subatomic particle contributes negligibly to atomic mass?

Explanation:

Link:

Question (8)

An atom has mass number 40 and contains 22 neutrons. Find its atomic number.

Explanation:

Link:

Question (9)

Which of the following electronic configurations represents a noble gas?

Explanation:

Link:

Question (10)

An atom has 20 protons and 20 neutrons. Which statement is correct?

Explanation:

Link:

Excel With Tutors

ExcelWithTutors

For Student

For Tutors

Learn

OUR POLICY