14) The most stable conformation of 3-bromo-2-methylpentane, viewed through the C-2—C-3 bond (i. e., C-2 in the front, C-3 in the back):
H
H
Br
H
CH3
H.
Br
Br
CH
CH2CH3
CH3
CH3
H3C
CH3
I
CH3
Br
CH2CH3
II
H
CH(CH3)2
III
CH3
H
Br
A
H
CH3
H
H
IV
CH3
CH2CH3
V
a) I
b) II
c) III
d) IV
e) V
15 TL

nacl or sodium chloride is an ionic compound. this is because an ionic compound pertains to a compound that consists of positively and negatively charged ions. in this case, na (sodium) has a tendency to lose one electron when it reacts with with other atoms, so the resulting sodium ion contains 11 protons and 10 electrons, thus making it positively charged (na+), when chlorine reacts, it usually gains one electron to form an ion called chloride, thus making it negatively charged ( since the ions are oppositely charged, they attract.

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.