How many grams are in 2.75 moles of Calcium

Which of the following did jj thompson discover about atoms? a)an atom has an internal structure. b) atoms are tiny indivisible particles. c)electrons orbit the nucleus of an atom. d) the nucleus of an atom contains protons and neutrons.

Define dew point. i am writing this part to be able to ask the question

The excretory system, need answers for all: )