Class 9 NCERT Solutions Structure of the Atom

Class 9 NCERT Solutions Structure of the Atom - NCERT Solutions prepared for CBSE students by the best teachers in Delhi. 

Class IX Science

 Chapter 4 – Structure of the Atom

Question 1:

What are canal rays?

Answer:

Canal rays are positively charged radiations. These rays consist of positively charged

particles known as protons. They were discovered by Goldstein in 1886.

Question 2:

If an atom contains one electron and one proton, will it carry any charge or not?

Answer:

An electron is a negatively charged particle, whereas a proton is a positively charged particle. The magnitude of their charges is equal. Therefore, an atom containing one electron and one proton will not carry any charge. Thus, it will be a neutral atom.

Question 3:

On the basis of Thomson’s model of an atom, explain how the atom is neutral as a whole.

Answer:

According to Thomson’s model of the atom, an atom consists of both negatively and positively charged particles. The negatively charged particles are embedded in the positively charged sphere. These negative and positive charges are equal in magnitude. Thus, by counterbalancing each other’s effect, they make an atom neutral.

Question 4:

On the basis of Rutherford’s model of an atom, which subatomic particle is present in the nucleus of an atom?

Answer:

On the basis of Rutherford's model of an atom, protons (positively-charged particles) are present in the nucleus of an atom.

Question 5:

Name the three sub-atomic particles of an atom.

Answer:

The three sub-atomic particles of an atom are:

(i) Protons

(ii) Electrons, and

(iii) Neutrons

Question 6:

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

Answer:

Helium atom has two neutrons. The mass of an atom is the sum of the masses of protons and neutrons present in its nucleus. Since helium atom has two protons,mass contributed by the two protons is (2 × 1) u = 2 u.

 

Students should free download the NCERT solutions and get better marks in exams. Studiestoday.com panel of teachers recommend students to practice questions in NCERT books and download NCERT solutions.

Tags: 

 


Click to View or Download pdf file
Click for more Science Study Material

Latest NCERT & CBSE News

Read the latest news and announcements from NCERT and CBSE below. Important updates relating to your studies which will help you to keep yourself updated with latest happenings in school level education. Keep yourself updated with all latest news and also read articles from teachers which will help you to improve your studies, increase motivation level and promote faster learning

Revised SOP preventive measures followed while conducting examinations

Revised SOP on preventive measures to be followed while conducting examinations to contain spread of COVID-19 issued by Ministry of Health & Family Welfare Examination centres are frequented by large number of students (as well as their parents) and staff till the...

Keep your kids engaged during Lockdown

Kids are the Future of our Country! Outlines have changed and so should the formats of existence! It is the best time to teach our kids the pleasure of Self-Discipline, Self-Realization and Self-Control. To keep the future generation safe in such unpredictable...

Conduct of the practical work during the lockdown

CBSE has advised schools to follow the Alternative Calendar developed by NCERT to continue education during the lockdown through alternative modes to achieve learning outcomes. Schools have reportedly started using these calendars and other prescribed pedagogical...

Online Teacher Training Course on Competency based Education in DIKSHA

Competency is a set of skills, abilities, knowledge that helps an individual perform a given task in real life. Every learning should go into the imbibing of these skills to lead a productive and joyful life. The NATIONAL EDUCATION POLICY-2020 calls for shift towards...

TERI Green Olympiad 2020

Green Olympiad is a value driven project conducted by TERI (The Energy and Resources Institute) for school students annually since 1999. This Olympiad assesses the environment quotient of students and also enhances their understanding on issues related to sustainable...

National Online Painting Championship

The National Mission for Clean Ganga, Ministry of Jal Shakti in collaboration with Kalantar Art Trust is organizing KALANTAR-2020: National Online Painting Championship with the aim to provide a platform to youth and school children to demonstrate their artistic skills...

×
Studies Today