Which one of the following is a pure substance?

Which of these is the result of scientific research and not engineering? a. a new shoe design that features air cushioning for more comfort and protection b. the creation of glass with uv protection. c. a conclusion about diet commonalities among diabetics. d. the development of a smaller, more compact missile.

What does standard deviation reveal about data? a. the average of all the data points b. which of the data points is most reliable c. how spread out the data points are d. the percent error included in the data

One or more substances changing into one or more substances is an example of a