Using your knowledge of symbols, determine which compound listed must contain both copper and oxygen. 1. malachite, Cu 2CO 3(OH) 2
2. calcite, CaCO 3
3. glucose, C 6H 12O 6
4. chalcopyrite, CuFeS 2

Malachite

Explanation:

Malachite is the only listed compound that must contain copper and oxygen.

Copper and oxygen are both elements found on the periodic table. They have the following symbols;

         Copper  = Cu

         Oxygen  = O

From the given choices, only option 1 has the symbol Cu and O.

So only malachite contains both copper and oxygen.

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.