Answer:
V₁ = 96.2 mL
Explanation:
Given data:
Initial volume of NH₄OH required = ?
Initial molarity = 15.6 M
Final molarity = 3.00 M
Final volume = 500.0 mL
Solution:
Formula:
M₁V₁ = M₂V₂
M₁ = Initial molarity
V₁ = Initial volume of NH₄OH
M₂ =Final molarity
V₂ = Final volume
Now we will put the values.
15.6 M ×V₁ = 3.00 M×500.0 mL
15.6 M ×V₁ = 1500 M.mL
V₁ = 1500 M.mL /15.6 M
V₁ = 96.2 mL
7 protons. As well as in nitrogen-14. The difference between nitrogen-14 and nitrogen-15 is in a number of neutrons. In nitrogen-14 - 7 neutrons, in nitrogen-15 - 8 neutrons.
The radon-222 sample has a half-life of 3.8 days, and we are asked how many times would the mass divide in half after 23 days. First we calculate the amount of times division occurs by taking the number of days and dividing that by the number of days for one half-life to occur: 23/3.8 = 6.05.
We have 198.6 grams of sample, and we are going to divide it in half 6 times to determine how much of it remains after 23 days:
198.6/2 = 99.3 grams
99.3/2 = 49.65 grams
49.65/2 = 24.83 grams
24.83/2 = 12.41 grams
12.41/2 = 6.21 grams
6.21/2 = 3.1 grams
Therefore, we are left with 3.1 grams of radon-222 after 23 days if one half-life equals to 3.8 days.
You did not provide possible answers, but one possible might be that the current atomic theory is so sound and plausible that there should not be anything that could change it in the near future.
The answer should be B. hope this helped ;)
