Using the periodic table, the pair of non metals that has the most similar properties would be :
Oxygen and Selenium
at the periodic table, these both located on the same period
hope this helps
Answer:
ExplaAt high temperatures MgCO3 decomposes to magnesium oxide and carbon dioxide. This process is important in the production of magnesium oxide. This process is called calcining: MgCO3 → MgO + CO2 (ΔH = +118 kJ/mol)
nation:
Proton neutron and electron
I would say penicillin, as it saved many lives in it's time and ours. Hope this helps!