I dont know how many eletrons would an atom from the following elements lose or gain. I need help?
to understand the gaining or losing of an electron an atom can have, first we have to relate it in their group number. Let me show you a similar example for this one.
group 1 = lose 1 electron
group 2= lose 2 electrons
group 15 = gains 3 electrons
group 16 = gains 2 electrons
group 17 = gains 1 electron
group 18 = neither gains or lose electrons
Look to what group does each of the atoms belong and you will know how many electrons a particular atom can gain or lose.
Ca in group 2 therefore it will lose 2 electrons
I is in group 17 therefore it will gain an electron.
for your question, let us try Oxygen.
Oxygen is in group 16 and according to our data it will gain 2 electrons.
If an atom already gained an electron, you will leave the the lose as blank
oxygen 0 2
hope this helps :)