An atom or ion has 7 protons, 7 neutrons, and 6 electrons. Is it positive, negative, or neutral? Why? What element is it?
Can someone please help!

Which formula can be used to calculate the molar mass of hydrogen peroxide

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following equation:

In the following table, all the columns for the element calcium are filled out correctly. element electron structure of atom electron structure of ion net ionic charge calcium 1s22s22p63s23p64s2 1s32s22p63s23p64s1 +1 true false