Which pair of elements has the most similar properties? A) N and P
B) K and He
C) I and CA
D) Li and B

So, the elements with similar properties to sodium (Na) are all of those elements in the same Group.

Explanation:

The ones "most" similar would be the ones closest in mass as well. Those would be Lithium (Li) and Potassium (K).

2b2t

explanation:

2b2t

answer is: nuclear fusion produces elements that are heavier than helium.

nuclei combine to form a heavier nucleus, releasing energy.  

for example, fusion of hydrogen atoms at the sun.  

this fusion nuclear reaction is in the inner core of the sun and hydrogen (atomic number 1) is conveted into helium (atomic number 2).  

the inner core is the central region of the sun and all solar energy is produced in the core by nuclear fusion.