CBSE Class 9 - CH4 - Structure of Atom (Worksheet)

Structure of Atom

Carbon-Atom
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Worksheet (Fill in the blanks)

1.  Atoms are made up of __________, ___________ and __________.

2. ________ rays are negatively charged.

3. The fundamental particle not present in hydrogen atom is __________.

4. Anode rays are also called ___________.

5. Rutherford's scattering experiment is related to to the size of ____________.


6. The fundamental sub-atomic particle called neutron was discovered by ___________.

7. In the three fundamental sub-atomic particles, _________ are negatively charged, _________ are positively charged and ____________ have no charges.

8. The _________ of an atom is dense, small in size and is positively charged.

9. The total number of protons and neutrons in the nucleus of an atom is called its __________.

10. Nucleons are __________ and ___________.

11. An atom has mass number 27 and atomic number 13. The atom has _________ electrons, _____ protons and _______ neutrons.

12. Atomic number is equal to _____________.

13. Valency is the __________ _____________ of an atom.

14. __________ electrons are located in the outermost shell of an atom.

15. The mass number of an atom is equal to the number of ________ in its nucleus.

16. The maximum number of electrons that can be accommodated in K-shell are _______.

17. The maximum number of electrons that can be accommodated in L-shell are _______.

18. ______ are atoms of the same element, which have same number of protons but different mass numbers.

19. _________ are atoms of different elements which have same number of neutrons but different mass numbers.

20. _______ are atoms having the same mass number but different atomic numbers.

21. Co-60 a radio isotope is used in treatment of __________.

22. Mass of a proton is __________ times the mass of an electron.


Answers:
1. electrons, protons, neutrons
2. cathode rays
3. neutron
4. canal rays
5. nucleus
6. J. Chadwick
7. electrons, protons, neutrons
8. nucleus
9. mass number
10. protons and neutrons
11. 13e, 13p, 14n
12. number of electrons or protons.
13. combining capacity
14. valence
15. nucleons
16. two (2)
17. eight (8)
18. Isotopes
19. Isotones
20. Isobars
21. cancer
22.  1836 or 2000 (appox.)