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 element with electron configuration 1s\(^2\) 2s\(^2\) 2p\(^6\) 3s\(^2\) 3p\(^1\) belongs to
s-block period 3, group 1
p-block, period 3, group 2
s-block, period 3, group 3
p-block, period 3, group 3
Correct answer is D
1s\(^2\) 2s\(^2\) 2p\(^6\) 3s\(^2\) 3p\(^1\) = 2, 8, 3.
The element is in period 3 and group 3.
Which of the following arrangements represents the correct order of electronic energy level?
1s 2p 2s 3p 3s 3d 4s
1s 2s 2p 3s 3p 3d 4s
1s 2s 2p 3s 3p 4s 3d
1s 2s 3s 2p 3p 4s 3d
Correct answer is C
The correct order of electronic energy level is OPTION C according to the Aufbau principle.
Which of the following statements is correct?
Atomic size decreases down the group
Atomic size increases across the period
Anions are smaller than the parent atom
Cations are smaller than the parent atom
Correct answer is D
A cation is a positively charged ion. This means electron is given out by a cation, hence the cation is smaller than the parent atom.
An atom of an element X gains two electrons. The symbol of the ion formed is
X +
X 2+
X 2-
X -
Correct answer is C
X gained two electrons. X = 2-.
The ion formed is X\(^{2-}\).
The formula of the compound formed between a trivalent metal, M and a divalent non-metal, Y is
M2Y3
M3Y2
MY
M3Y
Correct answer is A
M is a trivalent metal i.e M = 3+ ; Y is a divalent non-metal i.e Y = 2-
A reaction between M and Y will yield M\(_2\)Y\(_3\).