Answer:
A solution is made by dissolving 4.87 g of potassium nitrate in water to a final volume of 86.4 mL solution. The weight/weight % or percent by mass of the solute is :
<u>2.67%</u>
Explanation:
Note : Look at the density of potassium nitrate in water if given in the question.
<u><em>You are calculating </em></u><u><em>weight /Volume</em></u><u><em> not weight/weight % or percent by mass of the solute</em></u>
Here the <u>weight/weight % or percent by mass</u> of the solute is asked : So first convert the<u> VOLUME OF SOLUTION into MASS</u>
Density of potassium nitrate in water KNO3 = 2.11 g/mL

Density = 2.11 g/mL
Volume of solution = 86.4 mL



Mass of Solute = 4.87 g
Mass of Solution = 183.2 g
w/w% of the solute =


w/w%=2.67%
The half-life of any substance is the amount of time taken for half of the original quantity of the substance present to decay. The half-life of a radioactive substance is characteristic to itself, and it may be millions of years long or it may be just a few seconds.
In order to determine the half-life of a substance, we simply use:
t(1/2) = ln(2) / λ
Where λ is the decay constant for that specific isotope.
Answer:
Light changes speed in a glass of water.
Explanation: