Paper 3 · atomic structure
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
