Most students learn to use percents in middle school, but many people still have trouble interpreting information involving percents even as adults. Let's make some notes from these examples. The mechanics of changing a percent to a decimal number involves moving the decimal point two places to the left. Before looking at how percents come up in science, we need to be able to answer questions like those below. Click on the question to look at how to find the answer.
Percents come up several times in chemistry.
Remember that the key is to change a percent to a number before calculating with it and, if the answer is to be stated as a percent, convert the number to a percent before giving the answer. Notice that the percents add up to 100. Our experiment actually produces 871.2 g. Check your work. Check your work.