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>
Explanation:
On the whole, the metals burn in oxygen to form a simple metal oxide. Beryllium is reluctant to burn unless it is in the form of dust or powder. Beryllium has a very strong (but very thin) layer of beryllium oxide on its surface, and this prevents any new oxygen getting at the underlying beryllium to react with it
The highest point is the crest
