Question

Which of these processes indicates that smelting copper is a chemical change

a)it involves melting copper to form liquid metal
b)it involves heating charcoal to high tempuratures
c)it involves drawing copper into long wires
d)it involves breaking molecular bonds between copper compounds

Answer 1

Answer is d. The material can be phsycal changes into a differnt shape or state (gas, liquid, solid) and its will still be essentially copper. A chemical change is changing what other elements or compound is bonded to the copper atoms

Answer 2

The correct answer is D:

it involves breaking molecular bonds between copper compounds .

The explanation :

-when we melt a copper it is a physical change because the substance is still copper and have the same shape.

- but for example Burning a copper it is a chemical change. Fire activates a chemical reaction between copper and oxygen.

-The oxygen in the air reacts with the copper and the chemical bonds are broken.

- the chemical change is changing the other compound bonded to the copper atoms.

So, the correct answer is D