Question

In Lesson 20, a magnesium strip was used to ignite the thermite reaction. When magnesium is placed in a flame from a small blow torch, it burns quite brightly forming magnesium oxide, a salt that contains one magnesium for every oxygen. In the following questions you will be asked to provide some details of the chemical processes involved in a reaction between magnesium and oxygen. How many more electrons does unbound oxygen need to fill its 2nd shell?

Answer 1

2 electrons will be needed by unbound oxygen in order to fill its 2nd shell.

Step-by-step explanation:

The chemical reaction between magnesium and oxygen gives magnesium oxide as a product.The reaction is chemically represented as:

`2Mg(s)+O_2(g)\rightarrow 2MgO(s)`

Magnesium is a metal of group-2 with 2 valence electrons.It has atomic number of 12.

`[Mg]=1s^22s^22p^63s^2`

In order to attain noble gas configuration it will loose two electrons.

`[Mg]^(2+)=1s^22s^22p^6`

`Mg\rightarrow Mg^(2+)+2e^-`...[1]

Oxygen is a non metal of group-16 with 6 valence electrons..It has atomic number of 8.

`[O]=1s^22s^22p^4`

In order to attain noble gas configuration it will gain two electrons.

`[O]^(2-)=1s^22s^22p^6`

`O+2e^-\rightarrow O^(2-)`..[2]

2 electrons will be needed by unbound oxygen in order to fill its 2nd shell.