Mordern phy - 2 Flashcards
- charge on atom -
- no. of electron -
- amu -
- 1amu =
- mp =
- me =
- mn =
- charge on atom - 0
- no. of electron = no. of proton
- amu - atomic mass unit
- 1amu = c12 mass/ 12
= 1.67 * 10^ -27 kg - mp = 1.672 * 10^ -27 kg
- me = 9.1 * 10 -31
- mn = 1.674 * 10^ -27 kg
Z =
A =
nucleons =
no of neutron =
Z = atomic no. or no. of protons
A = mass no or no of protns + no of neutrons
nucleons = no of protns + no of neutrons
no of neutron = A -Z
wht is nucleus
- ZXA
- centre part of atom, have +ve charge
- proton and neutron in nucleues electron in orbit revolve
radius of nucleus
R = R0 A^ 1/3
R0?
constant
- 1.2 fermi
- fermi = 10^ -15
order of radius
10^ -10
volumes of nucleus
V directl prop A
V = 4/3 pie R0^3 A
mass of nucleus
mass of proton - mp
no . of proton - Z
mass of nuetron - mn
n. of neutron - A-Z
mpz + mn[A-Z] = Amp
density of nucleus
density = mn/vol.
= Amp/ 4/3 pie RO ^3 A
= 2.4*10^17 kg/m cube
types of nuclei?
isotope - same protons Z
isobar - same mass no. A
isotones - same neutons A-Z
which nuclie is unstable
heavy and light
why neutrons are unstable in nucleus?
due to mass of neutrons
nuclear force properties and grpah
- it is independent of charge
- it is spin dependnt
- distance dependent
- very short range force
- graph
mass defect
1. mass of mucleus =
2.mass of atom =
mass defect
1. mass of mucleus = Zmp + (A-Z)mn - Mx
Mx = mass of nucleus
2.mass of atom = Zmp + (A-Z)mn + Zme - Matom
Matom = mass of atom
binding energy
Eb = delta mc ^2
energy required to split nucleus into nucleons
binding energy per nucleons
Eb/ A
- it predicts info about stability of nucleus
- maximum for 26 fe 56
- graph 1st incerease then decrease
- greater the binding energy per nucleons more stable is the nuclie
- medium size nuclei is stablt then higher or medium size nuclei
types of nuclear reaction q
nuclear fission
nuclear fusion
nuclear fission
- splitting of heavy nucleus [ A> 230 ]
- some mass disappears and converts into enrgy
- equation A + n ————> B +C +Q
- U 235 + no’ ————> Ba + Kr + 200 Mev
- U 235 + no’ ————> Xe + Sr + 200 Mev
mass defect = mass of r - mass of p
mass defect = 0.1 %
energy in form of KE and heat = 97%
energy in form of r radiation = 3%
nuclear reactor
- for controlled chain reactin
- nuclear fuel - U 235 , Pu 239
- moderator - to slow down speed of neutron D2O
- cooling pad - Cd and B rod to absorb neutron
- coolant - cold water at high pressure to absorb heat
nuclear fusion
- when 2 or more than 2 nuclei fuse to form a heavier nuclei
- A+ B ————> C + Q
- mass of a + mass of b > mass of c
- mass defect delta m = mass of p - mass of r
- Q = Eb of product - Eb of reactant
realtion bw nuclear fission and fusion
energy release in fission is greater than fusion
- energy released per nucleons is greater in fusion
condition for fusion
- high temp
- high pressure
alpha decay
- A-4
- Z- 2
- ALPHA realese
- Q release
beta minus decay
- A - 0
- Z +1
- beta -1 realease
- wave no. release
- Q release
beta plus decay
- A - 0
- Z -1
- beta +1 realease
- wave no. release
- Q release
gamma decay
1. no. of alpha partciel [Nalpha]
2. no. of beta particle
gama rays
onlyyyyy
1. [Nalpha] = Ai - Af / 4
2. zf - { zi - 2 [Nalpha] }
