How do the stated properties vary as Group II is descended from magnesium to barium?
- Adecomposition temperature of the carbonate decreases; first ionisation energy decreases
- Bdecomposition temperature of the carbonate decreases; first ionisation energy increases
- Cdecomposition temperature of the carbonate increases; first ionisation energy decreases
- Ddecomposition temperature of the carbonate increases; first ionisation energy increases