Draw the Lewis dot structure for Mg and S. Is it an ionic or covalent bond?

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shedrick333 eNotes educator | Certified Educator

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This is an ionic bond.  Magnesium, found in group 2, has 2 valence electrons and needs to release them to become stable.  Sulfur, found in group 16, has 6 valence electrons and takes two from magnesium to become stable.

I like to say, "Eight is Great," to help students remember that atoms need eight electrons in the valance (outer energy level) to be stable.

It could be shown as [Mg 2+]  [S 2-].  The Mg would have no dots, and the S would have 8 around it, two on each side, top, and bottom.  The dots would be drawn inside the brackets  around the symbols.  The 2+ and 2- should be smaller and towards the top.

Mg becomes more positive and the S becomes more negative because electrons are negatively charged.


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mssigman eNotes educator | Certified Educator

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The Lewis dot structure for Magnesium is an Mg with 2 dots which stand for its two valence electrons.

The Lewis dot structure for Sulfur is an S with 6 dots which stand for its six valence electrons.

These two elements when bonded together form an ionic bond as the Magnesium loses its two valence electrons to the Sulfur atom.  Both atoms then have complete outer electron shells.  The Magnesium atom has a +2 charge and the Sulfur atom has a -2 charge.  This is what causes the attraction that bonds these two atoms.

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maria-vivanco | Student

I did my best in drawing this. 

But in general, since Mg and S is a ionic bond(because Mg is metal and S is nonmetal). Mg loses its  two  valence electrons and S gains two for them to have a octet configuration. 

Excuse my drawing i did my best

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Jyotsana | Student

Mg Ionic Covalent- 2ve

S   Molecular Covalent -6ve

go4knowledge2 | Student

In this case, Mg will lose 2electrons.

And S will gain the two electrons.

Mg(+2)+S(-2) = MgS

And the bond formed between Mg and S will be ionic.

Electron dot structures are:






ella301 | Student


0 Mg 0 x S x



Mg will donate 2 electrons to sulphur to attain stability or octet structure so it will become Mg(+2)

S will accept 2 electrons from Mg to attain stability or octet structure so it will become S(-2)

Mg(+2) + S(-2) = MgS.

forms ionic bond

shivankshekhar | Student

atomic number of mg is 12. therefore it's conf. is 2,8,2.Hence it has 2 e- in it's outermost orbit.S has Z=16, hence it's electronic conf. is 2,8,6. Hence it has 6 e- in it's outermost orbit.

..                                                                                     Mg:      : S :

Mg will give 2 e- and becomes stable &  S accepts 2e- to become stable.Thus,                                                                                                    ..                                                                                   Mg       : :S:



shaznl1 | Student

It s definitely an ionic bond. MgS(magnesium sulfide) is a very useful compound in chemistry. Mg has 2 valance electrons in its outermost level, and sulfur has 6 valance electrons. Mg's stable ion is the Mg2+ ion, which is a positive ion. Sulfur's stable ion is S2- ion, which is a negative ion. By the fundamental law of physics and chemistry, positive and negative attract each other, creating bonds. The bond created by positive and negative ion attracted to each other is an ionic bond.

Besides, ionic bond is ALWAYS a metal + a nonmetal. covalent bonds are always 2 nonmetals. In this case, sulfur is a nonmetal, and Mg is a metal. Therefore, they form an ionic bond.

shik6991 | Student

it will be an ionic bond


donleonardo | Student

The Lewis dot structure for MgS (Magnesium sulfide) is difficult to draw in this format.

Iprefer to use a small circle for the metals and a dot for the nonmetal.  This way you can 'see'(distinguish) each atoms electrons

Start by writing the symbol Mg and place a small circle at each the upper right and lower right sides(2 and 4 o'clock).  Then to the right of Mg (give yourself a little space) write the symbol S. Starting at 2 o'clock place a dot,  then place one at 4, 8, and 10 o'clock, respectively).  You have now accounted for 4 of sulfurs 6 valence electrons.  Now place a dot next to the ones at 2 and 4 o'clock.

o----.     :

Mg        S

o----.     :

The dashed line represents the bonding electron pairs.

Now for the QUESTION - is this an ionic bond.

First check the electronegativity(the desire to give up or take electrons) for each element.  Magnesium (Mg) has an electronegativity of 1.29 and sulfur's is 2.46.  Take the difference in electronegativity (2.46-1.29) 1.17.  This then will tell you the type bond (covalent - sharing) (polar-covalent - uneven sharing) or (ionic -little to no sharing of electrons).  It is generally accepted that if the difference in elecrtonegativities is GREATER than 1.7 the bond is ionic (>50% ionic).  Between 0.7 and 1.7 polar covalent (eg. water H2O ~1.1) and less than 0.7 covalent (eg. Nickel(II)sulfide NiS ~0.6,   H2 difference = 0 PURE covalent bond)

Thus NO compound is purely ionic.

Difference in electornegativity


covalent---------polar covalent----------------  ionic------  XXX

Hope this helped clear up covalent vs ionic bonds a little.


shizza123 | Student

Here's something new I found for you...

Mg2+    -Mg plus no dots (since it has lost its two valence electrons)

S2-       -S plus 8 dots (since it has six valence electrons, plus two more it got from Mg)

IONIC BOND because a metal is donating electrons to a non metal.

shizza123 | Student

write Mg and beside it, write S.

draw one dot at the top for one valence electron. draw one dot on the right side for two valence... and so forth...

then donate one electron from one atom to the other (using arrows), depending on which one needs it most.

remember, when you make dots, go in clockwise direction :)

abhinay | Student

its an ionic bond


vidushi01 | Student


0 Mg 0 x S x



Mg will donate 2 electrons to sulphur to attain stability or octet structure so it will become Mg(+2)

S will accept 2 electrons from Mg to attain stability or octet structure so it will become S(-2)

Mg(+2)   +   S(-2)  = MgS.

forms ionic bond

irza | Student

It is an ionic bond because magnesium is a metal and sulfur is a non-metal.

revolution | Student

It is more probably an ionic bond, which each two losing or gaining two electrons to get a stable electronic configuration.

hbridges95 | Student

Probably ionic.But im not sure


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