1s2 2s2 2p6 3s2 3p6 Atoms of an element, X, have the electronic configuration shown above. The compound most likely formed with magnesium, Mg, is (a) MgX (b) Mg2X (c) MgX2 (d) MgX3 (e) Mg3X2

The branch of science which deals with chemicals and bonds is called chemistry.

The correct option is D.

The representation of electrons in their shell is called electronic configuration. To find the element we have to count the electrons in it.

The total number of electrons is 2+2+6+2+6 = 18 which is argon a noble gas element.

The valency of the magnesium is 3, Hence the compound they will make is.

Hence the correct option is D that is MgX3.

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The question is incorrect, the correct question is:

1s2 2s2 2p6 3s2 3p3

Atoms of an element, X, have the electronic configuration shown above. The compound most likely formed

with magnesium, Mg, is

a. MgX

b. Mg2X

c. MgX2

d. Mg2X3

e. Mg3X2

e. Mg3X2

Explanation:

Let us reexamine  the electronic configuration of atom X; 1s2 2s2 2p6 3s2 3p3 .

This implies that it is a member of group 15 whose outer electronic configuration is ns2 np3. Members of group 15 have a valency of 3.

Therefore, during exchange of valence, the subscript of X becomes 2 (valency of magnesium) and the subscript of Mg becomes 3(valency of X).

Hence the formula is Mg3X2 as shown in the answer.

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.