A sample of Ar(g) is contained in a cylinder with a moveable piston at an initial
temperature of T. The volume of the
sample is decreased from 4.5 L to 1.5 L
while the pressure is held constant, as
shown in the diagram below.

Option (B) is correct.

Explanation:

Initial temperature of the gas is T.

The volume of the  sample is decreased from 4.5 L to 1.5 L  while the pressure is held constant.

At constant pressure, the relation between volume and temperature is given by :

Here, V₁ = 4.5 L, V₂ = 1.5 L, T₁ = T₁, T₂ = ?

So,

So, the final temperature of the gas is . Hence, the correct option is (B).

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.