What is it called when an element has 2 little numbers on top of each other on the left of the element?

If a plot weight (in g) vs. volume (in ml) for a metal gave the equation y= 13.41x and r^2=0.9981 what is the density of the metal?

All of the following are homogeneous mixtures except a) sugar dissolved in water. b) orange juice. c) coffee with cream. d) household vinegar. e) apple juice

Show how to convert the temperature 84.7° c to kelvin. include all steps and label the final answer