What is the atomic mass of an atom that has 3 protons and 4 neutrons

Which substance has non polar covalent bonds

Use the periodic table to complete this equation that represents nuclear fission processesun - ba c 3 n

Quickly what are the following of organisms that existed over a wide area but only for a limited time period called a. soft fossils b. mold fossils c. index fossils d. trace fossils