Chemistry Practice Tests – Atomic Structure and Chemical Combination

The line observed in the simple hydrogen spectrum are due to emission of ______ (JAMB 1998)

A. electrons from the atom
B. energy by proton transition
C. energy by electron transition
D. neutrons from the atom.

The electrons of two atoms Y and Z are arranged in shells as shown above. The bond formed between the atoms of Y and Z is _____ (JAMB 1991)

The stability of ionic solids ¡s generally due to the _____

A. negative electron affinity of most atoms
B. crystal lattice forces
C. electron pair sharing
D. positive ionization potentials.

Oxygen is a mixture of two ¡isotopes and with relative abundances of 90% and 10% respectively. The relative atomic mass of oxygen is _____ (JAMB 1997)

A. 16.0
B. 16.2
C. 17.0
D. 18.0

An element, E, has the electronic configuration 1s² 2s² 2p⁶ 3s² 3p³. The reaction of E with a halogen X can give _____ (JAMB 1993)

A. EX₃ and EX₅
B. EX₃ only
C. EX₅ only
D. EX₂ and EX₃