4) Some seawater is evaporated. The sea salt obtained is found to be 86% sodium chond. How much sodium chloride
could be obtained from 200 g of this salt?
5 ) 5.0 g sample of dry ice (solid carbon dioxide) turned into
2400 cm³ of carbon dioxide gas at rtp. What was the
percentage purity of the dry ice? (Mr of co², =44)​

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.