<u>a) Answer: </u>
<em>Number of molecules in 1 mole</em>
<u>Explanation:</u>
a) Whether we take any of the substance among all three of the given substances they will have the same number of molecules in 1 mole of the substance is considered and the value for this will be 
<u>b) Answer: </u>
<em>In the given question </em><em>mass of the substance</em><em> which is </em><em>greatest</em><em> is asked for </em><em>one mole</em><em> and we also know that </em><em>mass of one mole is given by molar mass. </em>
<u>Explanation:</u>
b) It is known that 
is the molar mass for oxygen which is greater than that of hydrogen while fluorine has a molar mass of 
which on comparison shows that, it is the highest amongst all three.
Usually the controlled experiment is the one that is not tested so they look at the experimental experiment to find the differences. Sorry if this doesn't answer your question.
Hey there!
A half-life means after a certain amount of time, half of that substance will be gone/changed after that time.
How many half-lives are in 16 days?
Multiply 16 by 24 (to get the total hours) and divide that by 2.5.
That is 153.6 half-lives.
35(0.5)^(153.6) represents the equation for this.
Simplify this and get 8.88 x 10^(-45).
There will be 2.02 x 10^(-45)g of germanium-66 sample remaining after 16 days.
Hope this helps!
