Answer:
An atom containing 11 electrons
Explanation:
Metal atoms form ions by a loss of electrons whereas non-metal atoms form ions by the gain of electrons.
The group 1 elements or alkali metals form lose their one valence shell electrons when forming ions; Group 2 metals lose two while Group 3 lose three. On the other hand, non-metal atoms found in Group 5, 6, and 7 forms ions by gaining one, two and three electrons respectively.
Using the electronic configuration of atoms, their groups in the Periodic Table can be determined.
An atom containing 6 electrons has the configuration 2,4 and thus belongs to Group 4.
An atom with 2 electrons belongs to Group 2
An atom with 11 electrons has the configuration 2,8,1 and thus belongs to Group 1
An atom with 10 electrons has the configuration 2,8 and thus belongs to Group 8
An atom with 8 electrons has the configuration 2,6 and thus belongs to Group 6.
From the above, it can be seen that an atom containing 11 electrons belongs to Group 1 and will lose an electron to form an ion.