Gold cannot be dissolved by any acid. However, it can be dissolved by aqua regia (kingly water) which is a mixture of: A. Mineral water and iodine B. nitric and hydrochloric acids C. water and sulphur D. alcohol and alum

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?