Which one does NOT belong?

Exercise and reference answers

Questions

1. Items

   1. Potassium
   2. Gold
   3. Sodium
   4. Calcium

   Reason

   Gold sits at the bottom of the reactivity series. The other three are among the most reactive metals.

   Odd item

   Gold

2. Items

   1. Aluminium oxide
   2. Zinc oxide
   3. Sodium oxide
   4. Amphoteric behaviour

   Reason

   Sodium oxide is purely basic. Aluminium oxide and zinc oxide are the amphoteric ones.

   Odd item

   Sodium oxide

3. Items

   1. Galvanising
   2. Chrome plating
   3. Anodising
   4. Roasting

   Reason

   Roasting is a step in extracting a metal. The other three are ways of preventing corrosion.

   Odd item

   Roasting

Instructions

Tap the item that does not belong with the rest.

Explanation