Describe Bohr’s model of the atom.
Solution and Explanation
Postulates of Bohr’s Model of an Atom
→ The atom consists of a small positively charged nucleus at its center.
→ The whole mass of the atom is concentrated at the nucleus and the volume of the nucleus is much smaller than the volume of the atom.
→ All the protons and neutrons of the atom are contained in the nucleus.
→ Only certain orbits known as discrete orbits of electrons are allowed inside the atom.
→ While revolving in these discrete orbits electrons do not radiate energy. These orbits or cells are represented by the letters K, L, M, N etc. or the numbers, n = 1, 2, 3, 4,.... as shown in below figure.
Top CBSE Class IX Questions
- The following table gives the lifetimes of 400 neon lamps:
Length (in hours)
Number of lamps
300 − 400
14
400 − 500
56
500 − 600
60
600 − 700
86
700 − 800
74
800 − 900
62
900 − 1000
48
(i) Represent the given information with the help of a histogram.
(ii) How many lamps have a lifetime of more than 700 hours? - Give an example to show that even as a young girl Santosh was not ready to accept anything unreasonable.
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- What do you think Dinamani is the name of? Give a reason for your answer.
Why was Santosh sent to the local school?