The chemical activity of metals generally increases as you move down a group in the periodic table. Based on this trend, the order of the given metals according to increasing chemical activity is as follows:
- Magnesium (Mg): Magnesium is the least reactive among the given metals. It reacts slowly with water and requires heat to react with acids.
- Calcium (Ca): Calcium is more reactive than magnesium. It reacts with water at room temperature, though not as vigorously as the alkali metals.
- Sodium (Na): Sodium is more reactive than calcium. It reacts vigorously with water, producing hydrogen gas and heat.
- Potassium (K): Potassium is more reactive than sodium. It reacts explosively with water, producing hydrogen gas and a significant amount of heat.
- Cesium (Cs): Cesium is the most reactive among the given metals. It reacts violently with water, often causing an explosion due to the rapid release of hydrogen gas and heat.
In summary, the order of increasing chemical activity is: Magnesium < Calcium < Sodium < Potassium < Cesium.