LNG and CNG are made frm natural gases .
What is the advantage of LNG over CNG ?

What is CNG?

In Appollo space programme the fuel cells are used not only for electric power but also for prepare H_2 O for drinking. What do-you understand by a fuel cell? What are the advantages of fuel cells over ordinary cells?

A newly married couple wantstemporary birth control measures for six months. What is the advantages and disadvantages of natural methods?

LEDS that can emit red, yellow, orange, etc. commercially available.What are its advantages over ordinary bulbs?

How many Galvanic cells can be made by using the metals Ag, Cu, Zn and Mg. When Galvanic cells are made using the metals given, what will be the nature of reactions in each cell? (Reactivity: Mg gt Zn gt Cu gt Ag).