Na is cation so it loses electron to be positive and become stable losing one valence shells one electron so it's oxidation number is +1 ie A is correct
Answer:
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Answer:
the atomic number is 5
the atomic mass is 11
Explanation:
The atomic number is the amount of protons inside the nucleus, and this number also equals the amount of electrons. Since it shows you the nucleus and the electrons, all you need to do is count the protons (positive charge inside the nucleus) or count all the electrons (negative charge outside the nucleus, in the rings) and you should have your atomic number.
As for mass, all you need to do is count all the protons and neutrons inside the nucleus and add them up. Protons = 5, Neutrons = 6. (you add them since the equation for atomic mass is Atomic Mass = Protons + neutrons. This works every time)
5+6= 11, so your atomic mass is 11
I hope this helps :)