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.
Which of the following metals has the strongest metallic bond?
13Al
19K
12Mg
11Na
Correct answer is A
Aluminium has the highest magnitude of charge of +3, hence it will form a stronger metallic bond.
The oxidation number of nitrogen in Pb(NO3)2 is
+2
+3
+4
+5
Correct answer is D
Pb(NO3)2 = +2+2N+(−2×6)=0
= 2N=10
⇒ N=+5
The reason for the decrease in the atomic size of elements across a period is that
nuclear charge increases while the outermost electrons are drawn closer to the nucleus
nuclear charge decreases while the outermost electrons are drawn closer to the nucleus
valence electrons increase across the period while the valence shell remains constant
nuclear charge decreases while the distance of the valence shell from the nucleus is increasing
Correct answer is A
This is caused by the increase in the number of protons and electrons across a period.
The property of elements which increases down a group of the periodic table is
electronegativity
electron affinity
onic radius
ionization energy
Correct answer is C
The ionic radius decreases across a period but increases along a group.