Answer:
Therefore it will take 7.66 hours for 80% of the lead decay.
Explanation:
The differential equation for decay is


Integrating both sides
ln A= kt+c₁

[
]
The initial condition is A(0)= A₀,


.........(1)
Given that the
has half life of 3.3 hours.
For half life
putting this in equation (1)

[taking ln both sides,
]

⇒k= - 0.21
Now A₀= 1 gram, 80%=0.8
and A= (1-0.8)A₀ = (0.2×1) gram = 0.2 gram
Now putting the value of k,A and A₀in the equation (1)




⇒ t≈7.66
Therefore it will take 7.66 hours for 80% of the lead decay.
I believe it is b electric energy etc...
Answer:
- <u>Tellurium (Te) and iodine (I) are two elements </u><em><u>next to each other that have decreasing atomic masses.</u></em>
Explanation:
The <em>atomic mass</em> of tellurium (Te) is 127.60 g/mol and the atomic mass of iodine (I) is 126.904 g/mol; so, in spite of iodine being to the right of tellurium in the periodic table (because the atomic number of iodine is bigger than the atomic number of tellurium), the atomic mass of iodine is less than the atomic mass of tellurium.
The elements are arranged in increasing order of atomic number in the periodic table.
The atomic number is equal to the number of protons and the mass number is the sum of the protons and neutrons.
The mass number, except for the mass defect, represents the atomic mass of a particular isotope. But the atomic mass of an element is the weighted average of the atomic masses of the different natural isotopes of the element.
Normally, as the atomic number increases, you find that the atomic mass increases, so most of the elements in the periodic table, which as said are arranged in icreasing atomic number order, match with increasing atomic masses. But the relative isotope abundaces of the elements can change that.
It is the case that the most common isotopes of tellurium have atomic masses 128 amu and 130 amu, whilst most common isotopes of iodine have an atomic mass 127 amu. As result, tellurium has an average atomic mass of 127.60 g/mol whilst iodine has an average atomic mass of 126.904 g/mol.
The pressure in a sealed container means the volume of container is fixed
so we cannot change the volume of container hence gas
The other factors which can affect the pressure are
a) moles of gas : if we increase the moles of gas the pressure of gas will increase
b) Temperature: if we increase the pressure of gas the pressure of gas will increase due to increase in kinetic energy
So the following cannot increase pressure
a) decrease in moles of gas
b) decrease in temperature of gas