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4. Structure of The Atom Science class 9 in English Medium ncert book solutions Additional -Questions
4. Structure of The Atom Additional -Questions – Complete NCERT Book Solutions for Class 9 Science (English Medium). Get all chapter explanations, extra questions, solved examples and additional practice questions for 4. Structure of The Atom Additional -Questions to help you master concepts and score higher.
4. Structure of The Atom Science class 9 in English Medium ncert book solutions Additional -Questions
NCERT Solutions for Class 9 Science play an important role in helping students understand the concepts of the chapter 4. Structure of The Atom clearly. This chapter includes the topic Additional -Questions, which is essential from both academic and examination point of view. The solutions provided here are prepared strictly according to the latest NCERT syllabus and follow the guidelines of CBSE to ensure accuracy and relevance. Each question is explained in a simple and student-friendly manner so that learners can grasp the concepts without confusion. These NCERT Solutions are useful for regular study, homework help, and exam preparation. All textbook questions are solved step by step to improve problem-solving skills and conceptual clarity. Students of Class 9 studying Science can use these solutions to revise important topics, understand difficult questions, and practise effectively before examinations. The chapter 4. Structure of The Atom is explained in a structured way, making it easier for students to connect the theory with the topic Additional -Questions. By studying these updated NCERT Solutions for Class 9 Science, students can build a strong foundation, boost their confidence, and score better marks in school and board exams.
4. Structure of The Atom
Additional -Questions
Additional And Important Questions with solutions
Ques.1 – Why does an atom have neutral charge?
Ans. – As an atom have equal protons and electrons. The protons carry positive charge and electrons carry negative charge. Thus an atom has neutral charge.
Ques.2 – What is an alpha particle?
Ans. – Alpha particle is a double charged helium particle which has positive charge.
Ques.3 – Write the name of sub-atomic particles of an atom.
Ans. –
- Proton – it has positive charge.
- Electron – it has negative charge.
- Neutron – it has no charge.
Ques.4 – Name the founder of electron.
Ans. – J. J. Thomson
Ques.5 – What is canal rays?
Ans. – Canal rays were positively charged radiations of a gas discharged from the anode of discharged canal which ultimately led to the discovery of another sub-atomic particle.
Ques.6 – Whom does credit for discovery of proton go?
Ans – E. Goldstein.
Ques.7 – What are the limitations of J.J. Thomson’s model of the atom?
Ans. – Thomson’s model explained that atoms are electrically neutral, the results of experiments carried out by other scientists could not be explained by this model,
Ques.8 – What are the limitations of Rutherford’s model of the atom?
Ans. – According to electromagnetic principle Rutherford’s model of the atom makes unstable to an atom while an atom is stable.
Ques.9 – What postuletes Neils Bohr put about the model of an atom?
Ans. – Neils Bohr put forward the following postulates about the model of an atom:
- Only certain special orbits known as discrete orbits of electrons, are allowed inside the atom.
- While revolving in discrete orbits the electrons do not radiate energy.
Ques.10 – Describe Rutherford’s model of the atom.
Ans. – Rutherford put forward the nuclear model of an atom, which had the following features:
- There is a positively charged centre in an atom called the nucleus.
- Nearly all the mass of an atom resides in the nucleus.
- The electrons revolve around the nucleus in well-defined orbits.
- The size of the nucleus is very small as compared to the size of the atom.
See other sub-topics of this chapter:
1. Chapter Review 2. Text-book Questions 3. Additional -Questions 4. Additional -Questions 2 5. Additional -Questions 3