Great amounts of atomic energy are released when
a _______reaction occurs.
Great amounts of atomic energy
are released when a chemical reaction occurs. The process can be an exothermic reaction
or endothermic reaction depending on the substances involved in the reaction.
The molarity of a solution in which 55. 49 g of calcium chloride is dissolved in enough water to make 500. ml of solution is 1M.
<h3>What is molarity? </h3>
It is defined as number of moles of solute divided by volume of solution.
Given,
Mass of CaCl2 =55.49g
Molar mass of CaCl2 =40+35+35=110g
Mole= given mass/ molar mass
= 55.49/110=0.50mol.
Now, putting all values we get the molarity
Molarity =0.5×1000/500=1M
Thus, the molarity of given solution is 1M.
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Answer:
a) a0 was 46.2 grams
b) It will take 259 years
c) The fossil is 1845 years old
Explanation:
<em>An unknown radioactive substance has a half-life of 3.20hours . If 46.2g of the substance is currently present, what mass A0 was present 8.00 hours ago?</em>
A = A0 * (1/2)^(t/h)
⇒ with A = the final amount = 46.2 grams
⇒ A0 = the original amount
⇒ t = time = 8 hours
⇒ h = half-life time = 3.2 hours
46.2 = Ao*(1/2)^(8/3.2)
Ao = 261.35 grams
<em>Americium-241 is used in some smoke detectors. It is an alpha emitter with a half-life of 432 years. How long will it take in years for 34.0% of an Am-241 sample to decay?</em>
t = (ln(0.66))-0.693) * 432 = 259 years
It will take 259 years
<em>A fossil was analyzed and determined to have a carbon-14 level that is 80% that of living organisms. The half-life of C-14 is 5730 years. How old is the fossil?</em>
<em />
t = (ln(0.80))-0.693) * 5730 = 1845
The fossil is 1845 years old
There are a total of four quantum numbers that govern the
electrons. These are the principal quantum number (n), the angular quantum
number (l), the magnetic quantum number (ml) and lastly the spin quantum number
(ms). Each electron has a unit set of the four quantum numbers.
Since the first 3 quantum numbers is already specified, so
the remaining to be filled is the ms quantum number which can only have values
of +1/2 and -1/2. So we have 2 electrons.
Answer:
<span>2 electrons</span>
dont know what the web looks like but mushrooms are decomposers