You have 1.81 x 1024 atoms of iron (Fe). How many moles of iron do you have? 3.01 moles of Fe

0.30 moles of Fe

30 moles of Fe

10.9 moles of Fe

the answer is 75.0%.

i dont know the answe

c) should be the answer.

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.