Which of the following characteristics can be written only in space A? A) formed between atoms of similar electronegativities.
B) formed between two metal atoms mostly found on the left of the periodic table.
C) formed between two nonmetal atoms mostly found on the right of the periodic table.
D) formed between an atom that tends to lose electrons in an atom that tends to gain electrons.

dynamic equilibrium is the answer.

50.23 i believe is correct but don't quote me on that.

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.