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.
78 protons and 55 elections
55 protons and 78 neutrons
55 neutrons 78 electrons
78 protons and 55 neutrons
Correct answer is B
No explanation has been provided for this answer.
XY
YX
X2Y3
Y2X3
Correct answer is D
\(\frac{\text{Element X}}{1s^22s^21p^4}\)
Valency of X is 2
\(\frac{\text{Element Y}}{1s^22s^22p^63s^23P^1}\)
valency of Y is 3
There is an exchange of valency when a compound is being formed. Hence, we have Y\(_2\)X\(_3\)
electropositivity decreases from Li to Na to K
electronegativity decreases from Li to Na to K
the number of the electron shells increases from Li to Na to K
the elements are in the same period
Correct answer is C
No explanation has been provided for this answer.
737 mm Hg
763 mm Hg
777 mm Hg
783 mm Hg
Correct answer is A
No explanation has been provided for this answer.
25.0cm3
12.5 cm3
10.0 cm3
5.0cm3
Correct answer is B
No explanation has been provided for this answer.