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 transition metals is not attracted to external magnetic field?
Cu
Fe
Ti
Zn
Correct answer is A
The period 4 transition metals are scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), and zinc (Zn).
Diamagnetism results from the lack of unpaired electrons. Diamagnetic substances are substances that are repelled by magnetic fields.
The examples of diamagnetic materials are copper, gold, antimony, silver, lead and hydrogen.
The electron configuration of 26Fe3+ is?
[Ar]4s23d6
[AR]4s23d3
[AR]4s13d4
[AR]4s03d5
Correct answer is D
The neutral Iron atom has the electric configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d6.to write the electronic config. of Fe3+ we have to subtract 3 electrons from the outermost shell which is 4s and 3d orbitals. Thus we obtain the electronic configuration for Fe3+ as:
1s2 2s2 2p6 3s2 3p6 4s0 3d5
OR
[AR] 4s0 3d5.
Which of the following processes is used in food preservation in an industry?
Carbon dating
Ieeadiation of gamma rays
Nuclear fission
Nuclear fusion
Correct answer is B
No explanation has been provided for this answer.
Which of the following arrangements is in decreasing order of atomic radius?
Li>Be>C>
Li>B>Be>C
Li>Be>B>C
C>B>Be>Li
Correct answer is C
No explanation has been provided for this answer.
The two elements 11X and 19Y are in the same group because they have the same
valence electrons
ionization energy
number of shell
atomic size
Correct answer is A
No explanation has been provided for this answer.