A 1.53 mol sample of helium gas was placed in a balloon. Adding 7.00 mol of helium gas to the balloon increased its volume to 12.5 L. Assume that temperature and pressure remained constant. What was the initial volume of the balloon in liters?

chemists can use the electron cloud model to assign electrons to different atomic orbitals. atomic orbitals also explain the patterns in the periodic table

explanation:

explanation: no but i do not usually comment

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.