A hot air balloon of 257m^3 is made from 8.50kg of materials. The outside atmosphere is 1.00 atm, and 18C and pure N2 atmosphere. CH4 + 2 O2 --> CO2 + 2H2O dHrxn = -890 kJ
All heat from CH4 burning goes into all the air originally in the balloon before heating
SN2 = 0.55 J/gC

What mass in grams of CH4 needed to be burned to achieve neutral buoyancy?

they both have a y in them

i think it's c. if you look search electronic symbol on google and then click on wiki it shows you a

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.