Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.
The idea of planetary electron was that of
Rutherford
Thompson
Bohr
Dalton
Correct answer is A
No explanation has been provided for this answer.
The order in which a mixture of sand, ammonium chloride and sodium chloride can be separated is
dissolution → dryness → filtration → evaporation
filtration → sublimation → evaporation → dryness
sublimation → dissolution → filtration → evaporation
dissolution → filtration → sublimation → evaporation
Correct answer is C
No explanation has been provided for this answer.
A decrease in atomic size and an increase in nuclear charge across a period lead to
an increase in the tendency to lose electron
an increase in chemical reactivity
a decrease in electropositivity
a decrease in covalency in bond formation
Correct answer is B
No explanation has been provided for this answer.
The element with the electron configuration 1s22s22p3 is
calcium
chlorine
oxygen
nitrogen
Correct answer is D
No explanation has been provided for this answer.
What is the molar mass of a substance, if 0.4 mole of the substance has a mass of 25.0g?
62.5 g
40.0 g
6.3 g
2.5 g
Correct answer is A
0.4 → 25
1 mole → ? = 1/0.4 * 25/1 = 250/1 = 62.5 g