Lesson 1: Atomic Strcuture

Question 1

Spectroscopy and the Atom

Answer 1

its the study of energy that is absorbed or emitted by matter.

• each element in the periodic table emits its own characteristic spectrum of light

Question 2

Ernest Rutherford used the element polonium in his gold foil experiment. What property of the element polonium makes it extremely dangerous to work with?

Answer 2

Ernest Rutherford used the element polonium because it is radioactive and it emits large alpha particles

Question 3

Rank the following forms of electromagnetic radiation in order of increasing energy: visible light, gamma rays, radio waves, infrared waves?

Answer 3

least to most:

radio waves, infrared waves, visible light, gamma rays

Question 4

Explain why atomic emission spectra are sometimes called fingerprints of the elements

Answer 4

Each element has a unique atomic emission spectrum similar to the way that each person has a unique fingerprint.

Question 5

Orbitals

Answer 5

• there are 4 diff orbitals, which are s,p,d,f
• there is only one type of s orbital and each s orbital can only accommodate 2 electrons
• x, y, z
• there are 3 diff orbitals that can hold up to 2 electrons meaning that a complete set of p orbitals can hold up to 6 electrons
• there are five d orbitals and 7 f orbitals

Question 6

What does the quantum mechanical model suggest?

Answer 6

that atoms consist of a nucleus surrounded by a combination or blend of orbitals containing electrons.

Question 7

Energy level diagrams

Answer 7

• shows the relative energies of the orbitals in an atom under normal conditions,.

Question 8

Energy level diagrams 
s - 1 (number of orbitals)
p - 3
d - 5
 f - 7

Answer 8

• the first energy level (n=1) which has the lowest energy of all contains only 1 orbital so it can hold up to 2 electrons. (1s)
• the first energy level is the closest to the nucleus
• 1 orbital = 2 electrons
• the second energy level (n=2) contains two types of orbitals s and p
• to find out how many orbitals there is use this formula n*2
• n=2 2*2 = 4
• n=4 has four orbitals

Question 9

What is the Pauli Exclusion Principle (OPPOSITE SPIN)

Answer 9

up and down arrow

• if there is only one elctron in the orbital then there is only 1 spin
• 2 electrons equals two spins
• The electron repulsion is minimized if the two electrons spin in opposite directions
• A second electron will be excluded from entry if it does not have the opposite spin

Question 10

Aufbau Principle (Lowest Fill First)

Answer 10

• when orbitals are filled with electrons the lowest energy are filled first
• look at the diagonal rule for orbital order

Question 11

What is Hunds Rule (ALIGN SPINS)

Answer 11

• when electrons are placed within a sub-level in which the orbitals have identical energy (p,d, or f) electron repulsion is minimized if each orbital receives one electron before pairing occurs.
• it creates fewer repulsions
• spreading it out

Question 12

How do the terms orbit and orbital differ?

Answer 12

The term orbit is used to describe the path of the electron in the Bohr model of the atom. In the model, the electron orbits the nucleus, much like a planet orbits the sun. The term orbital is used in the quantum mechanical model of the atom. It represents the probability region around the nucleus of the atom in which the likelihood of finding the electron is high.

Question 13

What is Neils bohr model of an atom?

Answer 13

depicts the atom as a small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus