Answer:
I am not so sure but I think it is A.
Explanation:
If i got it wrong sorry.... :(
The notation is actually written in this way (shown in the attached picture). The X is the symbol of the element. So, for potassium, the symbol is K. The A represents the mass number of the isotope. In this case, that would be equal to 39. The Z represents the atomic number of potassium, which is 19. Therefore, the symbol for the isotope is:
³⁹₁₉K
Answer:
A compound is "a substance formed when two or more chemical elements are chemically bonded together." There are two main types of chemical bonds: covalent and ionic.
Explanation:
Hope this helps!