Mercury thermometers work because mercury when it is warmed

Which of these properties, used alone, would be least useful in identifying most minerals? a. color b. luster c. streak d. density

Which characteristic of water it form droplets? a. low specific heat b. nonpolar structure c. high surface tension d. ability to dissolve substances

How many moles of lead are in 1.50 x 10^12 atoms of lead? could you explain the answer as well and not just give it to me i am refreshing for finals and i need to know how to do it