Positron emission = emission of a positron and a neutrino when a
proton is convert into a neutron. The total number of particles in the
nucleus doesn't change, -1 proton +1 neutron
It's a spontaneous reaction for some nucleus.
eg:
Positron = e+
Neutrino=ve
O-15 --> N-15 + e+ +ve
Electron
capture= A nucleus absorb an electron while a proton is convert in a
neutron and emit a neutrino. The total number of particles in the
nucleus doesn't change, -1 proton +1 neutron
eg:
Al-26 +e- --> Mg-26 + ve
Electron
capture and positron emission are two mechanisms to explain the decay
of some unstable isotopes. Electron capture is usually observed when the
energy difference between the initial and final state is low. Mainly
because of the larger amount of kinetic energy need for the expulsion
two particles with the positron emission mechanism.
Answer:
Calcium cyanamide
Explanation:
I think it has to be calcium cyanide, because of the cyanamide ion (CN).
<span>Tf is the freezing point of the solution(the solvent plus solute).
T*f is the freezing point of the pure solvent(without solute)
i is the van't Hoff factor.It is approximately the number of particles in solution that are made for each particle of the solute that is placed into solution.Therefore, for nonelectrolytes, i = 1.
Kf is the freezing point depression constant.For water, Kf = 1.86 Degree C/m, or 1.86 Degree C.kg/mol.
Tf is -1.58 Degree C</span>