I think it would be penicillin as it saved many lives in its time and ours.
Answer:
A) It shows how electrons are distributed in the Shells of an Iron atom.
Explanation: Took the test on Edge
d...................................................
Answer:
D no. is the answer of your question
A isotope is atoms of the same element with different amount of neutrons to change the mass. They can become more stable by sharing or giving away electrons to have a stable electron shell
