Will mark brainliest!!

Atoms form ions by gaining and losing electrons. They do this to become stable. Stability in an atom means that it obtains a full valence shell of electrons, usually 8, just like a noble gas! Match each element to the ion that it forms. Use your periodic table for this one!

Magnesium, an alkaline earth metal
Aluminum, a metal in group 13
Phosphorous, a nonmetal in group 15
Lithium, an alkali metal
Fluorine, a halogen

Options: +1, -3, +2, -1, +3

magnesium= +2

aluminum= +3

phosphorous= -3

lithium= +1

fluorine= -1

Explanation:

As fluorine having seven valance electrons in its outer most shell with atomic number nine. And for completing its outer most shell it needs one more electron that is why it form ion of -1 value.

Now  Aluminum has three electrons in its outer most shell with atomic number 13. So it need to lose these three electrons in order to be in stable state that is why it have ion in +3 state.

Same rule apply for other elements too.

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.