Exam 2 Review

Quantum Numbers

100

What does n describe?

N is the principle quantum number, and it describes the different energy levels of an atom.

200

Describe all the values of l and mₗ that exist for n=3

l = 0 mₗ = 0

l = 1 mₗ = -1, 0, 1

l = 2 mₗ = -2, -1, 0, 1, 2

300

Give each l value's corresponding orbital 

l = 0

l = 1

l = 2

l = 3

l = 0 = s

l = 1 = p

l = 2 = d

l = 3 = f

400

How many electrons can fit in each type of orbital (s, p, d, f)?

s orbitals can fit 2 electrons

p orbitals can fit 6 electrons

d orbitals can fit 10 electrons

f orbitals can fit 14 electrons

500

Calculate the change in energy when a Hydrogen atom makes the transition from n = 2 to n = 4. Is this atom absorbing or emitting energy? Explain your answer. 

5.45 x 10^-19 J

This atom is absorbing energy because it is going from a lower energy level, n = 2, to a higher energy level, n = 4.

Electron Configuration

100

Write the condensed electron configuration of Ca

[Ar]4s¹

200

Write the full electron configuration of Sc 

1s²2s²2p⁶3s²3p⁶4s²3d¹

300

Write the condensed electron configuration of Kr. How many valence electrons does it have? What would Kr's charge be? 

[Ar]3d¹⁰4s²4p⁶

^{Kr has 8 valence electrons because it is a noble gas. You can also tell by looking at how many electrons are in its highest energy levels (4s and 4p).}

^{Kr's expected charge would be 0, so it would be neutral. Kr is a noble gas with 8 valence electrons, so it is already stable.} 

400

What is the condensed electron configuration for Ni²⁺? Draw its orbital diagram. 

 [Ar]3d⁸

500

What is the condensed electron configuration of Ac? What are its valence electrons? 

[Rn]6d¹7s²

3 valence electrons

Energy of Light

100

What is the frequency of electromagnetic radiation with a wavelength of 500 nm?

6.00 x 10¹⁴  mHz

200

What is the wavelength of an electromagnetic wave with a frequency of 456 MHz?

0.658 m

300

What is the energy of a photon with a frequency of 4.21 GHz?

2.67 x 10^-24 J

400

Calculate the energy of a laser pulse with a wavelength of 456 nm.

4.36 x 10^{-19 J}

500

A laser pulse with the wavelength 352 nm contains 3.65 mJ of energy. How many photons are in the laser pulse?

6.46 x 10¹⁵ photons

Periodic Trends

100

Which element has a bigger radius? F or Br?

Br

200

Which ion has the bigger radius? Mg or Mg²⁺?

Mg

300

Which element has the highest first ionization energy? Zn, F, or K?

F

400

Write Cl, Cu, and C in order of increasing electron affinity.

Cu, C, Cl

500

Rank these elements in order of increasing metallic character and increasing nonmetallic character:

Co, Zn, Zr

metallic character: Zn, Co, Zr

nonmetallic character: Zr, Co, Zn

Wild Card

100

Draw an atom with 4 energy levels according to Bohr's model of an atom.

[Draw image on the board]

200

What form does light exist in?

It exists as both a wave and a particle. 

300

What are valence electrons? What are core electrons?

Valence electrons are electrons that exist in an atom's outer shell (higher energy shells). They are gained or lost in reactions.

Core electrons are electrons that exist in an atom's inner shells (lower energy shells). They are not involved in bonding. 

400

What are the different types of electromagnetic radiation?

radio, microwave, infrared, visible, ultraviolet, X-ray, and gamma ray

500

Explain the Pauli Exclusion Principle, Aufbau Principle, and Hund's rule.

Hint: All three of these principles relate to filling in orbital diagrams

Pauli Exclusion Principle: no 2 electrons can have the same 4 quantum numbers (2 electrons must be either up or down)

Aufbau Principle: Electrons fill up the lowest energy level before progressing to the highest energy level.

Hund's rule: every orbital in a sublevel (of equal energy) is filled in singly with one electron before being doubly filled with another electron. Each single electron will have a positive spin number, and each double electron will have a negative spin number.