Which one of the following is not an alkali metal:
A. Francium
B. Cesium
C. Rubidium
Is bronze an alloy, what is it made up of?
A. An alloy of copper and tin
B. An alloy of copper and Lead
C. An alloy of aluminium and tin
D. An alloy of copper and sulphur (more…)
The horizontal rows of the periodic table are called ______?
A. Groups
B. Periods
C. Sets
D. Matrices
How many valence electrons are in chlorine(cl) atom?
A. Chlorine has 1 valence electrons
B. Chlorine has 2 valence electrons
C. Chlorine has 7 valence electrons
D. Chlorine has 6 valence electrons (more…)
Intrinsic Semi-conductor is also called as__________?
A. Impure-Conductor
B. Pure-Conductor
C. Simple Conductor
D. None of these
Phosphorous contains which of the following?
A. Organisms
B. Soil and water
C. Air
D. All of above
Where ozone layer lies from the earth surface?
A. 10 to 20 km
B. 20 to 30 km
C. 30 to 40 km
D. 40 to 50 km
In physics, Sir Max Planck got noble prize in 1918 for his work on?
A. electron
B. energy quanta
C. photon
D. positron (more…)