Chapter 2, Problem 2.55AP

(a)

Interpretation Introduction

Interpretation:

The elements from cerium to lutetium is metal or non-metal has to be given.

Concept introduction:

Metal:

A metal is a material that, when freshly prepared, polished, or fractured, has a shiny appearance. Metal has the capacity to conducts the electricity and heat. Metals are malleable or ductile.

Non-metal:

Non-metal is an element that mostly absences metallic character.

Transition metal element:

Transition metal elements are 10 smaller groups which is located in middle of the periodic table.

(b)

Interpretation Introduction

Interpretation:

The class of the element from cerium to lutetuim should be identified.

Concept introduction:

Metal:

A metal is a material that, when freshly prepared, polished, or fractured, has a shiny appearance. Metal has the capacity to conducts the electricity and heat. Metals are malleable or ductile.

Non-metal:

Non-metal is an element that mostly absences metallic character.

Transition metal element:

Transition metal elements are 10 smaller groups which is located in middle of the periodic table.

(c)

Interpretation Introduction

Interpretation:

The name of the sub shell that is filled should be identified.

Concept introduction:

Electronic configuration:

The electron configuration is the distribution of electrons of an atom or molecule in atomic or molecular orbitals.

1. (1) Electrons occupy in the lowest energy orbitals. The increasing order of orbital energy is $\text{s, p, d and f}$. The lowest energy orbital is $\text{1s}$. The order of energy of the orbital for the for the first three period is given below,

   $\text{1s, 2s, 2p, 3s,}\text{and 3p}$.

2. (2) The orbital which is closer to the nucleus has lower energy, therefore the 2s is lower in energy than 3s. Accordingly $2s$ is lower in energy than $\text{2p and 4s}$ is lower in energy than $\text{3d}$.
3. (3) In general, the orbitals can hold maximum of two electrons, the two electrons must have opposite spin.

The subshell ordering by aufbau principle is given below, $\text{1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p, 8s, }\mathrm{...}$

Each shell contains only a fixed number of electrons. The first shell contains two electrons, the second shell contains eight (2 + 6) electrons, the third shell contains 18 (2 + 6 + 10), fourth shell contains (2 + 6 + 10 + 14 ) and so on.

Transition metal element:

Transition metal elements are 10 smaller groups which is located in middle of the periodic table.