Answer:
(a) 
(b)


(c) 
Explanation:
Hello,
(a) In this case, with the given formula we easily compute the mass of gold contained in the sovereign as shown below:

(b) Now, by knowing the density of gold and copper, 19.32 and 8.94 g/cm³ respectively, we compute each volume, by also knowing that the rest of the coin contains copper:


(c) Finally, the volume is computed by dividing the total mass over the total volume containing both gold and copper:

Best regards.
Procedures that are likely a chemical change are:
- Bubbles were produced when iron was placed in acid.
- Two liquids were combined, and a solid appeared
- A white substance turned blue when water was added.
Protons in science is positive