Chapter 4: Structure of Atom- Exercise- 49 B


Science

(www.olympiadsuccess.com)

Chapter 4: Structure of Atom

Class: IX

Exercise number 49B

 

Question 1

Name the three sub-atomic particles of an atom.

Answer 1

The three sub-atomic particles of an atom are:

(i) Protons

(ii) Neutrons, and

(iii) Electrons

Question 2

Helium atom has an atomic mass of 4 u and two protons in its nucleus. How many neutrons does it have?

Answer 2

It  has two neutrons. Because the mass of an atom is the sum of the masses of protons and

neutrons present in its nucleus.

Atmoic mas of helium =4 u (Given)

Given helium atom has two protons, mass contributed by the two protons is (2 × 1) u = 2 u.

Then, the remaining mass (4 − 2) u = 2 u is contributed by 2u /1u = 2 neutrons.

Other Chapters

Explore

SchoolPlus Program

Yearlong program for Olympiads preparation & to build necessary skills for future.

Explore More icon

Olympiad Exam Dates

Time to mark your calendar with the upcoming Olympiads exam schedule.

Explore More icon

LIVE Classes for Olympiads

Take your Olympiad preparation to next-level by taking LIVE Classes.

Explore More icon

Olympiad Test Series

Assess your performance by taking topic-wise and full length mock tests.

Explore More icon

India’s First Summer Olympiads

Know your true potential by participating in Unicus Olympiads for classes 1-11.

Explore More icon

Asia’s Biggest Winter Olympiads

Give wings to your innovation by appearing in CREST Olympiads for Prep/KG to classes 1-10.

Explore More icon

70%