Answer: a) 
b) 
Explanation:
a) If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
Mass of C = 15.8g
Mass of S= 84.2 g
Step 1 : convert given masses into moles.
Moles of C =
Moles of S=
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For C = 
For S =
The ratio of C : S = 1:2
Hence the empirical formula is 
b) Mass of C= 40 g
Mass of H= 6.7 g
Mass of O = 53.3 g
Step 1 : convert given masses into moles.
Moles of C =
Moles of H =
Moles of O =
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For C = 
For H = 
For O =
The ratio of C : H: O= 1 :2: 1
Hence the empirical formula is 
It is the mitochondria. Mitochondria are the power house of the cell and provide the cell with energy. Both plant and animal cells have mitochondria.
Answer:
The answer is
<h2>1.0 g/cm³</h2>
Explanation:
The density of a substance can be found by using the formula

From the question
mass = 10 g
volume = 10 cm³
It's density is

We have the final answer as
<h3>1.0 g/cm³</h3>
Hope this helps you