A crystallographer measures the horizontal spacing between molecules in a crystal. The spacing is 16.2 nm. What is the total width of a crystal in millimeters 10^5 molecules across? 10 molecules across? Write your answer as a decimal.

answer; the numbers of valence electrons in the acetic acid molecule (ch3co2h) is 24;

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.

im doing test rn im going with 2 but ill give answer if itss wrong,   : )