The half life equation is -->P(t) = Pi (0.5) ^ (t/c)
c is equal to the element to reach its half-life (5 seconds)t is equal to the duration of time the element is expose to (20 seconds)Pi is the initial amount (340)0.5 is the base of this exponential function to represent half-life.P(t) is the expression for the function of time
P(20) = 340 (0.5)^20/5P(20) = 340 (0.5) ^4P(20)= 21.25 grams
Fraction = P(t)/Pi = P(20)/Pi =21.25/340 =1/16
Therefore, when given 20 seconds, 340 grams of Fluorine-21 will degrade to 21.25 grams OR 1/16 of its original mass.
Hope this method helps! (This is my answer btw, I think you may have accidentally posted twice?)
Oceans :unusable
Rivers :usable
Glaciers :usable
Freshwater: usable
Lakes :usable
Groundwater :usable
Molarity= mol/ liters
since the molarity is given, we can assume that we have 1.0 Liters of solution
15.6 M= mol/ 1 liters---> this means that we have 15.6 moles of HNO3
we need to convert these moles to grams using the molar mass of HNO3
molar mass HNO3= 1.01 + 14.0 + (3 X 16.0)= 63.01 g/mol
15.6 mol HNO3 (63.01 g/ mol)= 983 grams HNO3
now we have to determine the grams of solution using the assumption of 1 liters of solution and the density
1 liters= 1000 mL
1000 mL (1.41 g/ ml)= 1410 grams solution
mass percent= mass of solute/ mass of solution x 100
mass percent= 63.01/ 1410 x 100= 4.47 %
Answer:
Noble gases are considered as Inert because they are unreactive.
Explanation:
Seven noble elments are known to us , they are: helium, neon, argon, krypton, xenon, radon, and oganesson. Noble gases have 8 electrons in their outermost shell and hence their valence shell is complete, they donot need further electrons to complete their octet so they are unreactive. Also they posses following properties.
Bleach would increase the pH because Bleach is a basic substance with a pH of about 12
Soda would lower the pH because the pH of sodas is somewhere around 2.5 (this is for coke, other sodas are a bit different)
