Density = mass/volume = 800/200 =4 g/cm^3
After 25 days, it remains radon 5.9x10^5 atoms.
Half-life is the time required for a quantity (in this example number of radioactive radon) to reduce to half its initial value.
N(Ra) = 5.7×10^7; initial number of radon atoms
t1/2(Ra) = 3.8 days; the half-life of the radon is 3.8 days
n = 25 days / 3.8 days
n = 6.58; number of half-lifes of radon
N1(Ra) = N(Ra) x (1/2)^n
N1(Ra) = 5.7×10^7 x (1/2)^6.58
N1(Ra) = 5.9x10^5; number of radon atoms after 25 days
The half-life is independent of initial concentration (size of the sample).
More about half-life: brainly.com/question/1160651
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The answer that h are looking for is c
Answer:
30.8 grams of nitric acid are produced
Explanation:
Let's state the reaction:
3 NO₂ + H₂O → 2 HNO₃ + NO
If water is the excess reagent, then the limiting is the gas.
We convert the mass to moles:
45 g . 1 mol/ 46 g = 0.978 moles
Ratio is 3:2. 3 moles of gas can produce 2 moles of acid
Then, 0.978 moles may produce (0.978 . 2) /3 = 0.652 moles of acid
This is the 100% yield, but in this case, the percent yield is 75%
0.652 moles . 0.75 = 0.489 moles
Let's convert the moles to mass → 0.489 mol . 63g / 1mol = 30.8 g
Answer:
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Explanation:
Which statement correctly describes how the parts of a flowering plant contribute to its survival? A. Roots prepare the plant for seed production, while the stem releases pollen for fertilization. B. Sepals prepare the plant for pollination, while the leaves collect oxygen for photosynthesis. C. Petals are involved in the reproductive cycle, while stamens protect the plant from predators. D. Ovaries are involved in fertilization and seed production, while anthers and
