Question

metals (reactivity trends)

1. arrange these metals in order of most reactive to least reactive: sodium (na), calcium (ca), potassium (k), aluminium (al).

• why did you put them in this order?

Explanation:

Step1: Recall metal reactivity

In the activity series, metals higher up are more reactive. Potassium (K) is very reactive as it has a single outer - shell electron and a large atomic radius, making it easy to lose an electron. Sodium (Na) is also quite reactive for similar reasons but less so than K. Calcium (Ca) has two outer - shell electrons and is less reactive than K and Na. Aluminium (Al) is less reactive than the previous three as it has a more stable electron configuration in its outer shell and a stronger nuclear pull on its electrons.

Step2: Order the metals

Based on the above - mentioned reactivity principles, the order from most reactive to least reactive is Potassium (K), Sodium (Na), Calcium (Ca), Aluminium (Al).

Answer:

Potassium (K), Sodium (Na), Calcium (Ca), Aluminium (Al)