If 50 mL of pure acetone is mixed with 450 mL of water, what is the percent by volume of acetone?

10%

Explanation:

The percent by volume of acetone is given by the following formula:

% v/v = Volume of acetone / Total Volume * 100%

Now we calculate the total volume of the solution:

Total Volume = Volume of Acetone + Volume of Water

Total Volume = 50 mL + 450 mL = 500 mL

Then we calculate the percent by volume:

% v/v = 50 mL / 500 mL * 100 % = 10%

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.