What is periodicity? What is the cause of periodicity?

What is heat period?

Define periodicity.

What is Tyndall effect ? What is the cause of it ?

What is laying period?

What is incubation period? What is the span of incubation period in case of AIDS?

What is the basis of modern periodic table?

Fig. 14.23 depicts four x t plots for linear motion of a particle. Which of the plots represent periodic motion? What is the period of motion (in case of periodic motion)

What is refractory period?

What are the effects of use of fertilizers and pesticides for long period on soil fertility ? What are the causes of soil erosion ?