What is gold used for? Why is cobalt chloride paper so useful? How much does a gold bullion bar weigh? Find out the answers to these and other fascinating questions in 'Gold and the Elements of Groups 8 to 12'. These elements are also called transition metals. Some occur naturally, and others are manufactured. In addition to gold, silver, and copper, other elements in these groups include ruthenium, osmium, rhodium, iridium, and palladium.