How is the mass number calculated for an element? a. the difference between the mass and the protons b. the sum of protons and neutrons c. there is no calculation. d. the product of neutrons and protons

The arrival of in the early days of europa’s existence could have formed its ocean. it is likely that the water experienced similar to earth. it is also possible that this water is retained beneath europa’s surface and in its atmosphere due to europa’s . 1.) a. precipitation b. water vapor c. icy debris 2.) a. gravitational compression b. biochemical cycling c. radiogenic heating 3.) a, gravity b. magnetic field c. heat energy for plato