Answer: 0.20 M
Explanation:
According to the dilution law,

where,
= molarity of stock solution = 1.40 M
= volume of stock solution = 72.0 ml
= molarity of diluted solution = m
= volume of diluted solution = 248 ml


Now 124 mL portion of this prepared solution is diluted by adding 133 mL of water.
According to the dilution law,

where,
= molarity of stock solution = 0.41 M
= volume of stock solution = 124 ml
= molarity of diluted solution = m
= volume of diluted solution = (124 +133) ml = 257 ml


Thus the final concentration of the solution is 0.20 M.
The cost of one antacid is 2.325 cents per tablet.
<u>Explanation:</u>
As per the question based on the student analysis we know that,
Total antacid tablets in a bottle = 120
Purchase Price of a bottle = $ 2.79
Cost of 1 antacid tablet
As we know $1 = 100 cent
The cost of 1 antacid tablet =
× 100 cents = 2.325 cents/tablet
.
Thus we came to know that it costs 2.325 cents/tablet
.
The two most abundant elements in Earths core are Iron and Nickel.
Hope this helps!
Two months later 13.8 milligrams of the barium-131 still be radioactive.
<h3>How is the decay rate of a radioactive substance expressed ? </h3>
It is expressed as:

where,
A = Amount remaining
A₀ = Initial Amount
t = time
T = Half life
Here
A₀ = 0.50g
t = 2 months = 60 days
T = 11.6 days
Now put the values in above expression we get



= 0.50 × 0.0277
= 0.0138 g
= 13.8 mg [1 mg = 1000 g]
Thus from the above conclusion we can say that Two months later 13.8 milligrams of the barium-131 still be radioactive.
Learn more about the Radioactive here: brainly.com/question/2320811
#SPJ1
Disclaimer: The question was given incomplete on the portal. Here is the complete question.
Question: Suppose that 0.50 grams of ban that 0.50 grams of barium-131 are administered orally to a patient. Approximately many milligrams of the barium would still be radioactive two months later? The half-life of barium-131 is 11.6 days.
11. Atomic number
12. in the nucleus with neutrons