Which element contains the greatest number of moles?
8 g of Helium
48 g of Carbon
78 g of Potassium
130g of Zinc
216g of Sliver
Correct answer is B
No explanation has been provided for this answer.
The use of sulphur to vulcanize rubber is mad to make it
blacker
cheaper
more elastic
tougher
softer
Correct answer is D
No explanation has been provided for this answer.
The atomic number of iron is 56. The number of unpaired electrons in the Fe3+ ion is
1
2
3
4
5
Correct answer is E
-There are 4 unpaired electrons in Fe
-However; 5 unpaired electrons are present in Fe3+
Animal charcoal differs from wood charcoal in that it
has a dark colour
has a high carbon content
is a good absorbent
is crystalline.
is rich in phosphate content
Correct answer is E
Animal charcoal or bone black is the carbonaceous residue obtained by the dry distillation of bones. It contains only about 10% carbon, the remaining being calcium and magnesium phosphates (80%) and other inorganic material originally present in the bones.
Which statement BEST describes the process of oxidation?
addition of hydrogen
loss of oxygen
decrease in oxidation number
loss of electrons
gain of elections.
Correct answer is D
No explanation has been provided for this answer.