Calculate the atomic mass of element x, atomic number 117 if: its abundance in nature as 320 rt (319.9897amu) is 81.9% and 321 rt (320.6897amu) is 18.1%

since electrons are negative the answer is neagtaive

може ли да зареждате повече информация, моля

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.