To solve this, we can use two equations.
t1/2 = ln 2 / λ = 0.693 / λ
where, t1/2 is half-life and λ is the decay constant.
t1/2 = 10 min = 0.693 / λ
Hence, λ = 0.693 / 10 min - (1)
Nt = Nο e∧(-λt)
Nt = amount of atoms at t =t time
Nο= initial amount of atoms
t = time taken
by rearranging the equation,
Nt/Nο = e∧(-λt) - (2)
From (1) and (2),
Nt/Nο = e∧(-(0.693 / 10 min) x 20 min)
Nt/Nο = 0.2500
Percentage of remaining nuclei = (nuclei at t time / initial nuclei) x 100%
= (Nt/Nο ) x 100%
= 0.2500 x 100%
= 25.00%
Hence, Percentage of remaining nuclei is 25.00%
<span>Mass of CO2 = 225.632g</span>
Answer:

Explanation:
Hello,
In this case, the enthalpy of combustion is understood as the energy released when one mole of fuel, in this case octene, is burned in the presence of oxygen and is computed with the enthalpies of formation of the fuel, carbon dioxide and water as shown below (oxygen is circumvented as it is a pure element):

Thus, since we already know the enthalpy of combustion of the fuel, for carbon and water we have -393.5 and -241.8 kJ/mol respectively, thereby, the enthalpy of combustion turns out:

Best regards.
Answer:
Aristotle believes that all material substances are matter and form.
Explanation:
If you remember from the four causes, the matter is one cause and form is another cause. Substance theory says that substances are the ultimate things in the universe
The puppies have different colored noses because of reccesive and dominant genotypes.
Genotypes are represented by letters, capital being dominant and lowercase being recessive.
For example, lets say t = pink nose and T = black nose.
If the parents have black noses, then they will pass on T genotypes.
But, they also have hidden pink nose genotypes.
These hidden genotypes are passed on to the puppies, one of the puppies gets more black nose genotypes.
If a puppy gets tt, they will have a pink nose.
If they get TT, they will have a black nose
If they get Tt, they will also have a black nose.
Because the black nose is dominant, its more likley for the puppies to end up with a black nose.