A. Methane
B. Hydrogyn
C. Oxygen
D. Carbin dioxide
Biogas comprises primarily methane (CH4) and carbon dioxide (CO2) and may have small amounts of hydrogen sulphide (H2S), moisture and siloxanes.
Which element is used as moderator in nuclear reactor?
A. Light water
B. Dense water
C. Fresh water
D. Heavy water
A. lactic acid
B. citric acid
C. acetic acid
D. carbonic acid
A. Manganese
B. Magnesium
C. Gypsum
D. Bauxite
E. None of these
A. NaAlO2
B. H2O
C. Al2O3
D. CaSiO3
Water is a chemical substance with the chemical formula H2O. Its molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth’s hydrosphere, and the fluids of most living organisms. It is vital for all known forms of life, even though it provides no calories or organic nutrients.
A. Silicon
B. Aluminium
C. Calcium
D. Sodium
A. Digestion
B. Respiration
C. Reproduction
D. Excretion