Explanation:
the inner core is solid. the outer core is liquid
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
Answer:
the ion present in the original solution is Ca2+
Explanation:
Precipitation reactions occur when cations and anions in aqueous solution combine to form an insoluble ionic solid called a precipitate.
<u>Step1</u> : If we add Nacl to the solution, there is no precipitate formed
⇒The only possible ion that can form a precipate with Cl- is Ag+; since there is no precipitate formed, Ag+ is not present
<u>Step2</u> : If we add Na2SO4 to the solution, a white precipitate is formed
The possible ions to bind at SO42- are Ca2+ and Fe2+
But the white precipitate formed, points in the direction of Ca2+
⇒This means calcium is present
<u>Step3</u> : If we add Na2CO3 to the filtered solution, there is a precipate formed
Ca2+ will bind also with CO32- and form a precipitate
So the ion present in the original solution is Ca2+
Answer:
F<S<Na<Ga<Sr
Explanation:
Atomic radius increased from the right of the periodic table to left, and from the top to the down
