Patrick S. answered • 08/09/13
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The answer would be: B. 1.2 x 10 ^ 2. Had your teacher not asked that you express your answer in scientific notation, 120 would have also been acceptable. When working with values which are expressed in scientific notation, one must take into account significant digits. B and C have both the same value, as well as the same number of sig figs. (with answer c., 120 has 2 sig figs. The "0" in "120" is what is called a trailing zero.) Measurements always have some degree of uncertainty. The only figures without some degree of uncertainty would be those that are the result of counting (i.e., instruments are not used), and thus they have an infinite number of sig figs.
