The rate of gas diffusion is ---Select--- proportional to temperature because a higher temperature means a/an increase in the kinetic energy of molecules. The rate of gas diffusion is ---Select--- proportional to the molecular weight of the gas because gas particles with higher masses require ---Select--- energy to move compared to gas particles with lower masses.

The rate of gas diffusion is directly proportional to temperature

Explanation:

The rate of gas diffusion is

a) directly proportional to square root of temperature

b)  inversely proportional to the square root of density

c) directly proportional to pressure

d) inversely proportional time and square root of molecular mass

Thus, option A is correct

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.