If 0.523 mol of argon occupies a volume of 723 ml at a particular temperature and pressure, what volume would 0.735 mol of argon occupy under the same conditions?

The gas 0.735/0.523=1.405moles.

so 1.405 times of gas is present than what was at the start. 0.523moles of argon took up 0.723L(723mL) so 1.405 times as much gas would take 1.405 times as much space. so the volume would be ,

1.405*0.723=1.015L

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.