3
5
7
10
Correct answer is C
No explanation has been provided for this answer.
Calcium hydroxide is added in the treatment of town water supply to
kill bacteria in the water
facilitate coagulation of organic particles
facilitate sedimentation
improve the taste of the water
Correct answer is B
No explanation has been provided for this answer.
extraction of aluminium from bauxite
production of margarine
smelting of copper
production of chlorine from brine
Correct answer is C
No explanation has been provided for this answer.
How many valence electrons are contained in the element represented 3115P?
3
5
15
31
Correct answer is B
No explanation has been provided for this answer.
P
Q
R
S
Correct answer is B
No explanation has been provided for this answer.