Which one of the following figures represents the age of the earth ?

• 4.6 million years
• 13.7 billion years
• 4.6 billion years
• 13.7 trillion years

What is the basic difference in the arguments related to the origin of the earth given by :

(a) Kant and Laplace

(b) Chamberlain and Moulton?

• Eons
• Period
• Era
• Epoch

• Solar winds
• Differentiation
• Degassing
• Photosynthesis