There are six quarks and six antiquarks. electrical charge exist in nature as integer multiples of electrical charge. Q=n*e no charge in nature exist in less than e. Quarks never exist in nature as single particles. they always make combination to other form other particles.

there are six leptons and six anti leptons. difference between quarks and leptons is, quarks cannnot be found in nature as in single particles but leptons can.

baryones- for example we combine a proton and a neutron.this composition is called uud.

mesones- 2 quak combinationbut one should be a antiquark.

forces which cannot be explained in terms of other forces are called fundamental forces.

splitting of a heavy nucleus to form a lighter nuclei. Fission products are more stable. Nuclear fission is the energy releasing process. uncontrol nuclear fission is used in nuclear bombs.

joining together of lighter nuclei to form a heavy nucleus. Nuclear fission is a energy releasing process.

atom consists of electrons,neutrons and protons. atomic structure(proton number)=Z mass number(nucleon number=(A ) (total of protons and neutrons) isotopes are elements which have same atomic number but different mass number. radioactivity is random, spontaneous emission of alpha,beta,gamma from unstable nuclei to gain stability. random=each nucleus in sample has same probability of emitting radiations at a given moment. spontaneous=rate of emission affected by environment surrounding conditions.

mass deflected for the reaction=(total mass of reactants)-(total mass of products)

when nucleus is formed from nucleons, energy is released in order to gain stability. Energy released comes from conversion of certain mass into energy so there's a difference between mass of nucleus and total mass of nucleon. This difference of the two masses is called mass detected. Δm=(Σmp+Σmn)mnucleus this is the energy released when a nucleus ids formed by joining a neutron and a proton. This is also the energy needed to split them apart too.

unified atomic mass(u)-unit of measuring mass of atoms and molecules.1/12 of mass of one c atom no. of grams =mass no. of any elements called 1mol. 1mol=6.02*10*23

electron unit(ev) work done in moving electron under p.d 1ev=p.d*charge =1v*1.6*10-19 ev is a unit of measuring energy.

electro magnetic radiation.speed is of light of speed.energy=0.1Mev.ionization power=least.range=any distance.penetration power=can be stopped by thick sheet of lead.since gamma is electro-magnetic radiation ,no change to proton number or mass number.

is identical to electron(negative beta) and positron(positive beta).speed is 98% of light of speed.energy=1Mev.ionization power=less.range=50m.penetration power=can be stopped by few millimeters of aluminum. beta minus decay-A Z X--------->A+0) (Z+0) Y+B- +V- (can be anti neutrino)+energy proton no. decreases by 1 but no change to mass no.cause a neutron converts to proton.down quark turns to a up quarks. is governed by weak nuclear forces. beta plus decay-A Z X--------->A (Z-1) Y+B+ +v- (can be electron neutrino)+energy proton no. decreases by 1 but no change to mass no.cause a proton converts to neutron.up quark turns to a down quarks. is governed by weak nuclear forces.

is identical to helium nucleus.4 2 He.speed is 5% of light of speed.energy=10Mev.ionization power=most.range=5cm.penetration power=can be stopped by paper A Z X → (A-4) (z-2) Y+ 4 2 alpha+Energy for any nucleus transformation to occur following conservation laws must be followed. 1)linear momentum must be conserved. 2)proton number/charge must be conserved. 3)mass number must be conserved. 4)mass and energy must be conserved. in alpha decay, always mass number is decreased by 4 and proton number is decreased by 2. alpha scattering experiment- beam of alpha is allowed to strike to a thin sheet of gold.path followed by alpha after striking with the gold foil is detected by a observing through a microscope. Most alpha particle passed through the sheet because most of the volume of an atom is empty space. Very rarely some alpha particles deflected by large angles(>90 degrees) because alpha has magnitude atomically charged and highly deviates. About one in 8000 is scattered back because positively charged highly dense region if confined to a very tiny volume.