Chap 16

Question 1

alpha particle nature, ionising effect and penetrative ability

Answer 1

-alpha particle contains 2 protons and two neutrons
-highest ionising effect
-lowest penetrative ability, being absorbed by a piece of paper

Question 2

beta particle nature, ionising effect and penetrative ability

Answer 2

-beta particle IS a fast moving electron ejected from nucleus
-medium ionising effect
-medium penetrative ability, stopped by a few millimeters thick aluminum sheet

Question 3

Gamma ray nature, ionising effect and penetrative ability

Answer 3

-gamma ray is an EM wave of excess energy from the nucleus
-lowest ionising effect
-highest penetrative ability, absorbed by few cm thick lead or very thick concrete

Question 4

what measures radioactivity

Answer 4

Geiger-Muller counter(GM counter)
SI unit : Becquerel(Bq)

Question 5

What is half life

Answer 5

time taken got half the nuclei of nuclide in a sample to decay

Question 6

What is the nature of radioactivity.

Answer 6

Radioactivity is random and spontaneous (happens at random instantly)