# Homework 14

- Page ID
- 28871

## Q 3.59

__Question:__ When each value of *n *is given, what are the possible values for *l*?

- 2
- 4
- 6
- 8

__Strategy:__

- The relationship between the quantum number (
*n*) and the angular momentum quantum number (*l*).- The principle quantum number is an integer that determines the overall size and energy of an orbital. The possible values for
*n*are 1, 2, 3, … and so on. - The angular momentum quantum number is an integer that determines the shape of the orbital. Every value of
*n*has a certain*l*value. In other words, for a given value of*n*,*l*can be any integer up to*n*-1.

- The principle quantum number is an integer that determines the overall size and energy of an orbital. The possible values for

__Example: __

If *n*=3, what are the possible values of *l*?

Since *l = n*-1, and n=3. Substitute 3 with *n *(*l=*3-1), which *l *equals to 2 maximum values or 0, 1, 2.

__Solution:__

*n*= 2

*l*= *n*-1

* l*= 0, 1

*n*= 4

* l*= *n*-1

*l*= 0, 1, 2, 3

*n*= 6

*l*= *n*-1

*l*= 0, 1, 2, 3, 4, 5

*n*= 8

*l*= *n*-1

* l*= 0, 1, 2, 3, 4, 5, 6, 7

## Q 6.53

__Question: __The formula CH_{4} is a tetrahedral geometry. How many electron groups are on the central atom?

__Strategy:__

- Valence Shell Electron Pair Repulsion (VSEPR) theory is based on the idea that electrons groups--- defined as lone pairs, single bonds, multiple bond, and single bonds--- repel one another.
- The repulsion between the electron groups determines the geometry of the molecule.
- The molecules that have one central atom molecular geometry depend on:
- The number of electron groups around the central atom.
- However many of those electron groups are bonding groups and how many are lone pairs.

__Solution:__

The formula CH_{4} is a tetrahedral geometry with four bonded pairs with no lone pairs, so there are four electron groups.