CLASS VII - SCIENCE - WORKSHEET- 4 - ATOMIC STRUCTURE- ANSWERS
WORKSHEET - 4
ATOMIC STRUCTURE
I. Multiple choice questions.
1. What is the average diameter of an atom?
Ans: a. 1 X 10-9m
2. _______ and ______ are particles called as nucleons.
Ans: c. Proton, Neutron
3. In a neutral atom, the number of protons are equal to ________.
Ans: b. Number of electrons
4. A chlorine atom has ____ protons _____ electrons and _____ neutrons.
Ans: 17,17,18
5. Sodium ion( Na+) has _____ number of electrons.
Ans: a. 10
6. Which of the following has equal number of neutrons and protons?
Ans: b. Deuterium and d. Calcium
7. A sulphur atom contains 16 protons and 16 neutrons. Calculate its atomic number and mass number.
Ans: a. 16,32
8. In 5B11 atom, find the number of protons, neutrons and electrons?
Ans: 5,6,5
9. X and Y are two atomic species.
Select the correct statement about X and Y
Ans: c. X and Y have different physical properties
10. Pick out the isobar pair.
Ans: 18Ar40, 20Ca40
11. Atomic number and mass number of sodium atom are 11 and 23 respectively. Find the number of neutrons in this atom?
Ans: c.12
12. Mg → Mg2+ + ____
Ans: a. 2 Electrons
13. Methane comprises of ______.
Ans: 1 carbon, 4 hydrogen
II. Answer briefly.
14. Draw the basic structure of an atom representing its
a)Electrons, b) Nucleus
1`5. Who am I?
I am essential to human beings for their healthy teeth and bones.
Ans: Calcium
I am 78% in the air. I am responsible for growth of plants.
Ans: Nitrogen
I am used to kill bacteria in drinking water.
Ans: Chlorine
16. Find the values of A,B,C,D in the table.