Quiz :)
I put like 50 points into this.

Explanation:

1. Same number of valence electrons.

2. Same number of electron shells.

7. Chlorine

8. Not sure.

Carbon: 2s2 2p2

Silicion: 3s² 3p²

Bromine: 3d¹⁰ 4s² 4p⁵

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.