A solution <span>has a uniform composition and is only able to be separated by chemical means.</span>
Answer:
A 12.630 bar of chocolate contains 8315 milligrams of sugar
Explanation:
From the basics of conversion, we can find that:
1 gram is equal to 1000 mg
Using cross multiplication, we can find how many milligrams are present in 8.315 grams as follows:
1 gram .............> 1000 mg
8.315 grams ....> ?? mg
amount in milligrams = (8.315*1000) / 1 = 8315 milligrams
Hope this helps :)
Half-life of a radioactive substance is the time required to reduce the amount of substance to half of its initial amount.
In present case, half-life is material is given as 1000 years and initial amount of material is given as 400 kg
Answer 1) Since, half-life of radio-active substance is 1000 years, therefore after 1st half life, amount of the material will be left to half the initial amount. Hence, amount of substance left after 1000 years = 400/2 = 200 kg.
Answer 2) For 2000 years, radioactive material has crossed 2 times the half life. Therefore , amount of the material will be left to 1/4 the initial amount. Hence, amount of substance left after 2000 years = 400/4 = 100 kg.
Answer 3) For 4000 years, radioactive material has crossed 4 times the half life. Therefore , amount of the material will be left to 1/16 the initial amount. Hence, amount of substance left after 4000 years = 400/16 = 25 kg.
22.4L
of any gas contains 1 mol of that gas.
50.75g/10L*22.4L/1 mol= 113.68g/mol- this is the mole weight of your gas
1 mol/113.68g*129.3g=1.137403 mol
Set up a ratio
1.137403mol/x L=1 mol/22.4 L
X=25.477827L, or with sig figs, x=25.5L
The primary reason for this was that Mendeleev
didn't know that atomic numbers actually existed. Atomic numbers
were only discovered a period after Mendeleev's time. The use of X-rays made it
possible to find the atomic number, and those had not been discovered yet. <span>
<span>The periodic table was then arranged in 1913 by Henry Moseley
in an arrangement according to atomic number.</span></span>
