Paper 3 · June 2009 · Atomic Structure and Bonding
What is the composition of the free radical of chlorine, ?
A17 protons, 18 neutrons, 16 electrons
B17 protons, 18 neutrons, 17 electrons
C18 protons, 17 neutrons, 17 electrons
D18 protons, 17 neutrons, 18 electrons
Explanation
The marking scheme gives answer B. has 17 protons and 18 neutrons. As a free radical it has one unpaired electron but the same number of electrons as protons (17), so it is neutral with 17 electrons.
ZIMSEC Chemistry Paper 3, June 2009, Q1