We know, Period = 1/frequency = 1/20 sec.
So, your final answer is 0.05 sec
Hope this helps!
Answer:
In odd nuclei, the left out proton or neutron will contribute to the spin of the nucleus.
Explanation:
The meaning of odd nuclei is atomic mass is odd.
A=odd number.
A=Z+n
Here, Z is proton either it will odd or n will odd which is neutron.
Now according to the shell model the left out proton or neutron will contribute to the spin and parity.
For example,
Take the case of isotope of nitrogen-15.
Here Z is 7, and n is 8 will not contribute in spin.
Now, for Z=7.

Here,

and, L=1.
Fort parity,

Put the value of L.
Parity will be -1.
Now, spin will be
.
The said development of the cell where the three cell layers help out do it is called as Gastrulation. The three layers - called as ectoderm, endoderm, and mesoderm - tend to form as this happens. This is a process that's present in all living things except sponges.