Question 3 Which element has (a) two shells, both of which are completely filled with electrons ? (b) the electronic configuration 2, 8, 2 ? (c) a total of three shells, with four electrons in its valence shell ? (d) a total of two shells with three electrons in its valence shell. v (e) twice as many electrons in its second shell as in its first shell ?

What type of questions asked from the lesson of magnetic effect of electric current 

Wavelength of green light is

A) 400-450 nm

B) 500-550 nm

C) 660-720 nm

D) 720-800 nm

What is the difference between anaerobic & aerobic respiration? Name some organism that uses the aerobic mode of respiration?

What are the main components of our environment? Explain each of them briefly.

What are examples of hydrotropism plants?