Here we have to discuss the understanding of world through radiocarbon or uranium.
The radiocarbon or uranium helps us to determine the age of the world.
All uranium or radiocarbon elements after ejecting the radioactive rays convert to non-radioactive element lead (²⁰⁸Pb). If we assume that during the generation of world there were not any amount of lead was present i.e. only uranium or radiocarbon was present. Then by analysis of any uranium or radiocarbon at the present date one can determine the age of the world as follows:
In present moment we know that the ratio of uranium (U) and lead (Pb) in any uranium ore is 10:3 (gram atom ratio)
So,
= 
Therefore, from the equation: ln
= λt (where λ = rate of dissociation of uranium, t = time); we can write:
t = λ⁻¹ ln
= λ⁻¹ln
.
On plugging the dissociation rate of uranium we can obtain the age of the world, which is nearly 1.5×10⁹ years.
Thus the use of radioactive element to understand the world is explained.
Answer:
D
Explanation:
its a very old study and philosophy of how to change basic substances such as metals into other substances
I dont get it someone please help
Answer: The theoretical yield of aspirin is 4.14 g
Explanation:
To calculate the moles :
mass of acetic anhydride =
According to stoichiometry :
1 mole of salycylic acid require 1 mole of acetic anhydride
Thus 0.023 moles of salycylic acid require=
of acetic anhydride
Thus salycylic acid is the limiting reagent as it limits the formation of product and acetic anhydride is the excess reagent.
As 1 mole of salycylic give = 1 mole of aspirin
Thus 0.023 moles of salycylic acid give =
of aspirin
Mass of aspirin =
Thus theoretical yield of aspirin is 4.14 g
The answer to your question is B.