10th science Refresher Course 10-ATOMIC STRUCTURE answer key

10th science Refresher Course 10-ATOMIC STRUCTURE answer key

Topic 1 - 

ATOMIC STRUCTURE

unit 1 - 10th Science ATOMIC STRUCTURE Answer

Title : 10th science Bridge course Answer Worksheet 10

10th science Refresher Course-10-ATOMIC STRUCTURE-answer key

 EVALUATION

I. Choose the best answer:

1. Cathode rays are made up of __________________

(a) Positively charged particles

(b) Neutral particles

(c) Negatively charged particles.

2. Who discovered electron?

(a) Rutherford (b) John Dalton (c) J.J. Thomson

3. _________________ was discovered by James Chadwick

(a) Newton (b) Proton (c) Electron

4. Mass of proton is _____________

(a) 1.6×10-24 grams (b) 9.1×10-28 grams (b) 1.6×10+24 grams

5. The negatively charged rays are called as _______________.

(a) Anode rays (b) Cathode rays (c) Electric rays

II. Fill in the blanks:

1. ________________ is the smallest particle of an element.

2. In water, hydrogen and oxygen are combined in the ratio of _____________ by mass.

3. Proton is deflected towards the ________________ charged plate (Positively / Negatively)

4. The law of conservation of Mass was started by ________________.

III. Find the valency:

1. The valency of C in Co2

2. The valency of Na in Na Cl

3. Cathode rays passes through ____________________

IV. MATCH:

a) Law of Conservation of Mass — Sir William Crookes

b) Law of Constant Proportion — James Chadwick

c) Cathode Rays — Joseph Proust

d) Anode Rays — Lavoisier

e) Neutrons — Goldstein

V. Fill in the blanks:

1. Same element having different mass number is called _____________

2. According to Dalton’s atomic theory, atoms can neither be _______________ nor be ______________

3. Electrons revolving around the nucleus in a circular path is called _________________

4. Total number of electrons that can be accommodated in an orbit is given by _____________

5. The valency of Argon is ___________

6. The total number of proton and neutron in an atom is called __________

7. Find the number of neutorns in an element

(i) 6C12= Number of neutron _______________

(ii) 18Ar40= Number of neutrons _______________

8. Nucleus Consists of _________________ and _________________

9. Calculate the number of neutrons, protons and electrons: given (i) atomic number 3 and mass  number 7

10. Cathode rays travel in _________________