The most common

element in the

universe is hydrogen followed by helium. Stars are made primarily of these two elements. Heavier elements are formed through fusion. The heaviest elements (elements with a

mass greater than that of iron) are formed during the super nova explosion of massive stars.

Notice that the

y-axis of the

graph is a logarithmic function. Logarithms are used to make enormous numbers, like 1 x 10

^{23}, into more manageable numbers, like 23 and 1 x 10

^{24} into 24. The important thing to remember about logarithms is that each increase in number is a 10-fold increase. On a log scale, the number 24 is TEN times bigger than the number 23.

For example, the Richter scale, well known for measuring the severity of earthquakes, is a logarithmic scale. An

earthquake that measures an 8 on the Richter

scale is 10 times more devastating than a quake that measures 7 on the Richter scale. Keep that in mind as you answer the following questions.