An answer befitting your question…
Hi mom, I’m having troubles with my teachers. They are cruel to me and I cannot concentrate. I think if we changed schools it would be much better. Thank you mom.
Sodium<span> has one naturally occurring </span>isotope<span>. The </span>nucleus<span> of this isotope contains 11 </span>protons<span> and 12 </span>neutrons<span> and is not radioactive. There are 18 other known isotopes of sodium. All are radioactive. Sodium-22, sodium's most stable radioactive isotope, has a </span>half-life<span> of 2.6 year</span>
Answer:
Nitrogen
Explanation:
Nitrogen has 5 Valence Electrons.
And its atomic mass is also less than Bismuth.
There are other elements in the 5th row but this one has the lowest atomic mass compared to the others.