Question

If a is a radioactive element which emits an - particle and produces 104rf 259. Write the atomic number and mass number of the element a

Answer 1

the reaction equation is 2X + 3O ----> X2O3 2 moles X produce 1 mole X2O3 let the molecular mass of X = M, so 1 g X = 1/M moles X, which produce 1/(2M) moles X2O3 ---> 1.1596 g X2O3 = 1/(2M) moles the molecular mass of X2O3 is (2M+ 3*16) = (2M+48) so 1.1596 g are 1.1596/(2M+48) moles together it follows, that 1/(2M) moles = 1.1596/(2M + 48) moles 2M+48 = 1.1596*2M 48 = 0.3192M M = 150.376 g