The tables gives the isotopes of an unknown element. The only value missing from the table is the atomic mass of isotope X-72. Using what you know about isotopes, do you think the atomic mass will be greater than, less than, or equal to the atomic mass of X-70 and why? A) Less than; X-72 has two less protons than X-70, which will give X-70 a lesser mass. B) Greater than; X-72 has two more neutrons than X-70, which will give X-72 a larger atomic mass. C) Equal to; X-70 and X-72 are isotopes of the same element so there masses are equal because they have the same number of protons. D) The the table does not provide enough information to determine if the atomic mass of isotope X-72 is greater than, less than, or equal to the atomic mass of isotope X-70. 2) If you know that the atomic mass for element X is 71.1, calculate the missing atomic mass in the table for isotope X-72. A) 67.7 B) 70.2 C) 71.1 D) 71.8