Answer:
The new pressure is 44.4 kPa.
Explanation:
We have,
Initial volume, 
Initial pressure, 
It is required to find the new pressure when the volume is increased to 50 ml. The relationship between pressure and volume is known as Boyle's law.

is final pressure

So, new pressure is 44.4 kPa.
Answer: The result is presented in proportion which gives a clearer understanding and accurate result.
Explanation: Percentage change in mass is the proportion of the initial mass of a substance changed after sometime. The results is presented as a percentage making it more accurate and can help to give future reference to weight calculations.
Change is Mass is the mass of a substance left after sometime mostly given in grams. It is not as accurate as percentage change in mass. It is generally better to show results in percentage change in mass as it gives a better understanding of what mass of a substance was lost after a given period or after application of energy like Heat or increased temperature.
50 grams or 50,000 mili grams is the mass of solute in 1000 grams of a solution having a concentration of 5 parts per million.
Explanation:
Total mass of solution = 1000 grams or 1000 ml since 1 gram = 1 ml
concentration is 5 parts per million ( 5 mg in 1000 ml solution or 0.005 gram in 1000 ml)
the formula used for parts per million:
parts per million = 
putting the values in the equation:
parts per million = 
0.005 x 1000 = mass of solute
50 grams= mass of solute
converting this into mg
50,000 mg. is the total mass of solute in 5ppm of 1000 ml solution.
Answer:
percentage by mass of each element in a compound.
Explanation:
False, Molecules are made of atoms and atoms are made of quarks.