1. By: Amna Al-Hammadi Science 8B

3. METALS DISCOVERY DATE  Rubidium  Potassium  Sodium  Barium  Calcium  Magnesium  Aluminum  Manganese  Zinc  Cobalt  Iron  Tin  Copper  Silver  Gold  1860  1807  1808  1825  1774  1746  1737  2000 BC  3000 BC  3500 BC  5000 BC 1

4.  Symbol: K  Atomic Mass: 39.0983  Atomic Number: 19 Potassium is a reactive metal it was discovered in 1807 (See in Chart) Potassium reacts rapidly with oxides to form oxides of itself also oxide in water forms hydroxide and hydrogen.

5.  Symbol: Ca  Atomic Mass: 40.078  Atomic Number: 20  Calcium is a metal that reacts with air to form Calcium Oxide and it was discovered in 1808. (See in Chart)

6.  Gold: Au  Atomic Mass: 196.97  Atomic Number: 79  Gold is a metal that is very unreactive even if it is left in water or oxygen for a long time. It was discovered in 5000 BC (See in Chart).

7.  So Yes there is a connection and a relationship of the reactivity and discovery date because as you saw the discovery date showed that most of the metals are discovered the same but just a year different for Potassium and Calcium except for Gold. Also for the reactivity Potassium and Calcium are also close and again except for Gold.