Theory and Electrical Conductivity Metals: 1 band of free electrons = conduction bond Non-Metals : the conduction band is occupied. E...
Theory and Electrical Conductivity
Metals: 1 band of free electrons = conduction bond
Non-Metals: the conduction band is occupied.
For an electron:
De-Broglie wavelength aka matter-wave = plank’s constant / momentum of an electron
I.e ^ = h/p
Electrons also show dual characteristics: ^ = h/mv
Dual characteristics of an electron:
1. Electrons interacts with matter as a particle
2. Electrons travels through space as wavelength
Parent Nucleus: Nucleus before the decay
Daughter Nucleus: Nucleus after the decay of an alpha particle
Mass and Energy:
Separate nucleons have more mass than the nucleus itself.
What happens is when we break the cohesively existing neutrons and protons, we give energy to them in order to separate them, ultimately increasing the mass.
#We charge them with nuclear potential energy.
Energy has mass
E = mc^2
E = Energy
m = mass
c = speed of light
Total mass before reaction: M1
Total mass after reaction: M2
The energy released + M2 = M1
The energy released = M1 = M2
Info: 1u is defined as 1/12th of the mass of a neutral atom of carbon-12
Mass excess: A little bit extra mass which is more than the total nucleon number.
Mass excess: = mass (in u) – nucleon number
#Note – sign shows energy is released
Minimum energy needed to pull a nucleus apart into separate nucleons.
We can find binding energy by:
1. Finding the mass defect (total mass of individual (protons and neutron aka nucleus) – mass of nucleon (together))
2. Multiply mass defect by c^2
3. Divide total energy by the number of nucleons (p +n)
Nuclear decay is spontaneous because:
1. Decay of the particular nucleus is not affected by the presence of other nuclei.
2. Temperature, Pressure etc does not affect the chemical reaction.
Nuclear decay is random because:
1. Impossible to predict when decaying will take place.
2. Each nucleus has same probability of being decayed at a time.
Probability that an individual nucleus will decay per unit time interval.