Answer:
12
Explanation:
the 4 by the element symbol O multiplied by the 3 on the outside of the parentheses
scandium is a transition metal and shows a valency of 3.
Answer:
A closed system is a physical system that does not allow transfer of matter in or out of the system, though, in different contexts, such as physics, chemistry or engineering, the transfer of energy is or is not allowed.
Explanation:
