Answer: 17 years
Explanation:
Expression for rate law for first order kinetics for radioactive substance is given by:

where,
k = rate constant
t = age of sample
a = let initial amount of the reactant
a - x = amount left after decay process
a) for completion of half life:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.


b) for 8900 g of the mass of the sample to reach 7700 grams


Thus it will take 17 years
Answer:
Drug calculation
If we have 45g of clobetasol = 0.05%w/w
Then what mass in g of clobetasol is in 0.03%w/w = 45 x 0.03/0.05 =27g
It means that 27g of clobetasol must be added to change the drug strength to 0.03% w/w
Answer:
Explanation:I would need more info to understand this question but explaining molecules is pretty easy tho
D is the correct answer
every other option contains an element
Answer:
The molarity of this sugar solution in water is 2.18 M
Explanation:
Step 1: Data given
Mass of sugar (C12H22O11) = 186.55 grams
Molar mass of C12H22O11 = 342.3 g/mol
Volume of water = 250.0 mL = 0.250 L
Step 2: Calculate moles sugar
Moles sugar = mass sugar / molar mass sugar
Moles sugar = 186.55 grams / 342.3 g/mol
Moles sugar = 0.545 moles
Step 3: Calculate molarity of the sugar solution
Molarity = moles sugar / volume of water
Molarity = 0.545 moles / 0.250 L
Molarity = 2.18 MThe molarity of this sugar solution in water is 2.18 M