Question

An element is placed in 2nd Group and 3rd Period of the Periodic Table, burns in presence of oxygen to form a basic oxide.

1. Identify the element
2. Write the electronic configuration
3. Write the balanced equation when it burns in the presence of air
4. Write a balanced equation when this oxide is dissolved in water
5. Draw the electron dot structure for the formation of this oxide

Answer 1

1. The element is magnesium (Mg).
2. Electronic configuration of the element is 2, 8, 2.
3. When magnesium burns in the air it forms magnesium oxide.
   \[\ce{2Mg(s) + O_2(g) -> 2MgO(s)}\]
4. When magnesium oxide is dissolved in water it forms magnesium hydroxide.
   \[\ce{MgO(s) + H2O(l) -> Mg(OH)2(aq)}\]
5.