Shells. 57 Download free eBooks at bookboon.com Fundamentals of Chemistry Electron Configuration Bonding Redox equations 6.5.4 Some other example H * H* *6* *H * H H H:C:H H H H:C:H H H H:C:H H H H-i-H methane 6.5.5 Exercise - A naturally occurring sample of tap water contains 0.1 5mg of Fe 3+ per dm 3 .