Half-life refers to the time taken for half of the atoms in a radioactive substance to decay. Therefore in 1 half-life the 80 mg of substance will reduce to 40 mg. In another half-life it will reduce from 40 mg to 20 mg, then in a third half-life from 20 mg to 10 mg. Therefore the half-life is equal to the total time taken to decay from 80 mg to 10 mg divided by 3:
t(1/2) = 36 hours / 3 = 12 hours.
Answer:
0.75 moles
Explanation:
S2 + 2O2 = 2SO2
From the reaction above,
We see that number of moles attached to S2 is 1 and number of moles attached to SO2 is 2.
Since we want to find how many moles of S2 are needed to produce 1.50 moles of SO2 gas
The answer is gotten by proportion;
Number of moles = 1/2 × 1.5 = 0.75 moles
<span>A mineral that has CLEAVAGE can be split fairly easily along the planes with a weak atomic attraction. Technically a mineral may have a luster but it isn't the cause of it's split. Additionally, hardened minerals is the opposite of what is being discussed and I cannot truly remember what "streak" meant in regards to minerals.</span>
<em>V= 110mL = 110cm³ = 0,11dm³</em>
<em>C = 1,244 mol/L = 1,244 mol/dm³</em>
C = n/V
n = 1,244×0,11
<u>n = 0,13684 moles</u>
<em>mCa(OH)₂ = 74 g/mol</em>
1 mole Ca(OH)₂ ------------ 74g
0,13684 ---------------------- X
X = 74×0,13684
<u>X = 10,12616g</u>
:)
