Hello!
The half-life is the time of half-disintegration, it is the time in which half of the atoms of an isotope disintegrate.
We have the following data:
mo (initial mass) = 20 g
m (final mass after time T) = 5 g
x (number of periods elapsed) = ?
P (Half-life) = ? (in minutes)
T (Elapsed time for sample reduction) = 8 minutes
Let's find the number of periods elapsed (x), let us see:






Now, let's find the half-life (P) of the radioactive sample, let's see:





I Hope this helps, greetings ... DexteR! =)
<span>Water soaks into it easily and during freeze-thaw cycles would be more likely to break apart because of the water freezing and thawing inside the rock. The water freezes and expands inside the rock, causing the surface to break off in flakes from the pressure of the expanding ice inside.</span>
The water and heathfshiccu
Answer:
The answer is 0.023 moles of phosphorus
Explanation:
The 15-15-15 fertilizer is a fertilizer of great versatility, made with nitrogen, phosphorus and potassium, which makes it one of the fertilizers most used for fertilizer in the sowing plant, thus covering the crop requirements from planting. .
This fertilizer consists of 14.25% phosphorus pentoxide (P2O5). Therefore, we have to remove 14.25% at 10 grams of 15-15-15 fertilizer to calculate the moles of phosphorus. As follows:
Grams of P2O5 = 10 g x 0.1425 = 1.425 g
We calculate the molecular weight of phosphorus. We use the periodic table:
Phosphorus molecular weight = 2 x 30.97 = 61.94 g/mol
Now we calculate the moles of phosphorus in the fertilizer:
Phosphorus moles = 1,425 g/61.94 g/mol = 0.023 moles
Dilution refers to decreasing the ratio of total solution to the reference solution by the addition of other liquids. By adding water to tomato soup, the balance of “tomato soup” molecules decreases from 100% tomato soup, to eventually 1:1 TS and Water (50%), and so on. Chemically, you can observe this as decreasing the concentration of tomato soup in this solution.