according to e=mc2, some of the mass changes into energy during any chemical reaction,but, energy has no mass. so, how mass changes into an object(energy) which has no mass.i need answer ,relativity has made me mad.my name is aryan singh.class 9e(going to 10).st xaviers delhi{CIVIL LINES}

it is a relation between energy and mass and mass get converted into energy when the particle travels at the speed of light which is ‘c’ in the given equation.energy and mass are two different aspects and it doesn’t mean that energy should have and all. if energy (radiation is taken ingeneral for energy in this case) contain mass then weight would be increased on sitting in a bright room. A practical example for this relation (e=mc2) is nuclear reaction in nuclear reaction when fast moving electron strikes the nucleus of uranium then in nucleus a proton gets converted into neutron and positron, and this fast moving positron collides with a fat moving electron and get converted into gamma radiation a form of energy see how mass(electron and positron) get converted into energy(gamma radiation). You will study a little about it in class 10 physics chapter name sources of energy

sorry a fast moving neutron strikes the nucleus, and fast moving electron strikes fast moving positron and gamma radiation also converts into positron and electron. it occurs when gamma radiation strikes a heavy metal