Problem page solid magnesium carbonate decomposes into carbon dioxide gas and solid magnesium oxide . write a balanced chemical equation for this reaction.

                  MgCO₃   →    MgO  +  CO₂

                    Chemical Formula of Magnesium Carbonate  =  MgCO₃

                    Chemical Formula of Magnesium Oxide  =  MgO

                    Chemical Formula of Carbon Dioxide  =  CO₂

Step 1: Write the unbalance (if present) chemical equation:

                                             MgCO₃    →    MgO  +  CO₂

Step 2: Calculate and balance number of atoms on each side:

Magnesium Atoms:

                              As there is one Mg on left hand side and one Mg atom on right hand side. Therefore, Mg atoms are balanced.

Carbon Atoms:

                       There is one C atom on right hand side of the equation and one C atom on left hand side of the equation. Hence, C atoms are balanced too.

Oxygen Atoms:

                        Oxygen atoms are also balances i.e. three atoms on both sides each.

                   Hence, 1 mole of MgCO₃ on decomposition produces 1 mole of CO₂ and 1 mole of MgO.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.