The periodic sign of magnesium is ------> mg
isotopes are the same element, but have different numbers of neutrons (but still have the same number of electrons and protons), hence have a different mass number.
The final mass after decay can be obtained by using under given relation:
half life period of As-81 = 33 seconds
mf = mi x (1/2^n)
= 100 x ( 1/2^(43.2/33))
= 40.4 %
Hi there!
Angular momentum is equivalent to:

L = angular momentum (kgm²/s)
I = moment of inertia (kgm²)
ω = angular velocity (rad/sec)
Plug in the given values for moment of inertia and angular speed:
