Answer:
= 72900 years
Explanation:
- The half-life is the time taken by a radioactive material to decay by half the original amount.
- The half-life of plutonium-239 is 24300 years which means it takes 24300 years to decay by half the original amount.
To calculate the time taken for a mass of 8 kg to decay to 1 kg we use;
New mass = Original mass x (1/2) ^n, where n is the number of half-lives
Therefore;
1 kg = 8 kg × (1/2)^n
1/8 = (1/2)^n
solving for n;
n =3
Therefore;
Time = 3 × 24300 years
= 72900 years
It will, therefore, take 72900 years for 8 kg of plutonium-239 to decay to 1 kg.
Answer : The temperature in kelvins is, 
Explanation : Given,
= 178.5 KJ/mole = 178500 J/mole
= 161.0 J/mole.K
Gibbs–Helmholtz equation is :
As per question the reaction is spontaneous that means the value of 
is negative or we can say that the value of is less than zero.
The above expression will be:
Now put all the given values in this expression, we get :
Therefore, the temperature in kelvins is,
They are made of different color of waxes
Answer:
The answer is 5. Compound
