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.
0.097 mm
0.194 mm
0.388 mm
2.388 mm
Correct answer is A
No explanation has been provided for this answer.
The shapes of CO2, H2O and CH 4 respectively are
bent, linear and tetrahedral
bent, tetrahedral and linear
linear, bent and tetrahedral
tetrahedral, linear and bent
Correct answer is C
No explanation has been provided for this answer.
The knowledge of half-life can be used to
create an element
detect an element
split an element
irradiate an element
Correct answer is B
No explanation has been provided for this answer.
Which of the following types of bonding does not involve the formation of new substance?
Metallic
covalent
Co-ordinate
Electrovalent
Correct answer is A
No explanation has been provided for this answer.
The electron configuration of \(_{22}X^{2+}\) ion is
1s2 2s22p6 3s2 3p6 4s2 3d2
1s2 2s22p6 3s2 3p6 4s2 3d1
1s2 2s22p6 3s2 3p6
1s2 2s22p6 3s2 3p6 3d2
Correct answer is D
\(_{22}X^{2+}\) has 22 electrons but has been ionized to 2+ by giving off 2 electrons. Hence, the ion \(_{22}X^{2+}\) has 20 electrons.
The electronic configuration = 1s\(^2\) 2s\(^2\) 2p\(^6\) 3s\(^2\) 3p\(^6\) 3d\(^2\)
the general trend for the first-row transition metals is that they lose electrons from their 4s orbitals first before 3d when forming ions. but this is not true for chromium and copper due to stability related to half-filled or completely-filled 3d orbitals