When a candle is lit and allowed to burn for 15 minutes, some wax drips and collects at the base of the candle, and the candle becomes shorter. Why did the candle become shorter? What happened to the missing section of the candle?

The missing section of the candle burns away and evaporates while some drips and collects at the base.

Explanation:

This is because a chemical reaction is occurring due to the heat, causing the molecule in the candles wax to move around faster and faster therefore causing melting.

the right answer is c i just did the question.

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.