If a gas occupies a volume of 0.25 l at -2.3 degrees celsius, by what amount would the volume increase if the gas were heated to 82 degrees at constant pressure

This in accordance with Boyle's law which states that the product of the initial pressure and volume is equal to the product of the final pressure and volume.

P1V1 = P2V2

Now compare this to Charles ' law which states that the product of the initial volume and the final temperature is equal to the product of the final volume and initial temperature.

V1T2= V2T1

Remember that all temperatures must be calculated in kelvin

If the initial temperature of 273 K is doubled to 546 K,
then a initial volume of 1.0 liter is also doubled, with a final volume of 2.0 liters.

first one is the correct answer

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.