Unit 2 Review. For a specific element the number of ______________ is the same but the number of ________ and ___________ may vary. Multiple forms of.

Unit 2 Review

For a specific element the number of ______________ is the same but the number of ________ and ___________ may vary.

Multiple forms of the same element with varying numbers of neutrons are called ________________.

The same element with extra or not enough electrons are called ________.

Mass number = _______________ + _______________ What are the two ways to write an isotope of carbon with

7 neutrons?

1. _______________ 2. _______________

Protons

Neutrons Electrons

Isotopes

# of Neutrons # of Protons

Ions

Carbon-13136C

Name the element which has:a. 1 proton _____________

b. 4 n0, 3 p+, 3 e-________

c. 30 n0, 26 e-, 26 p+_____________

d. 18 e-, 22 n0, 18 p+_____________

Hydrogen

Iron

Lithium

Argon

Barry (the Puma)Mickey Minnie

What are valence electrons? ____________________________________

How many valence electrons in the following atoms:

a. Al ________ b. P __________

c. Mg _________

The electrons in an atom’s outer most orbitals

3 5

2

R.I.P. Tina (the llama)

How do the electron configurations for the following elements end?

a. K _________ b. N __________

c. Kr _________

How are mass number and atomic mass different?

4s1 2p3

4p6

Mass number is the mass of the protons and neutrons combined. Atomic mass is the average mass of the element’s isotopes.

Put the following people in order and then tell what they contributed to the understanding of the atom:- Rutherford, Dalton, Aristotle, Thomson, Bohr, Democritus, Chadwick

Democritus: came up with the first idea of an atom

Aristotle: disagreed with DemocritusDalton: published his atomic theory (5 principles) in early 1800’s

* almost all still true today.Thomson: used Cathode Ray Tube Experiment to discover the first

subatomic particle, the electron.Rutherford: used the Gold Foil Experiment to prove the existence

of a small, dense, positive nucleus.Bohr: said electrons are in energy levels

Chadwick: discovered the neutron (hard to find b/c neutral & in center.)Quantum Mechanics – current model of the atom.

Explain the gold-foil experiment and the cathode-ray tube experiment. Remember Gold Foil Essay..

Review notes

Bob (the Manatee)

Why are atoms neutral?_____________________________

What is the charge of the nucleus of a Carbon atom?_____________________________

Particle Charge Mass Location

Electron

Proton

Neutron

Approximately 0Negative Space surrounding nucleus

Positive 1

Neutral 1

Inside nucleus

Inside nucleus

Equal numbers of negative electrons and positive protons

positive

Complete the table:Include the mass number and atomic number in names or symbols as discussed in class.

Element Symbol #p #n #e Mass # AtomicNumber

4 9

21 23

Aluminum-28

2 1

Al

Be

1313

Beryllium-9 5 4

23Vanadium-44 44 23

28

Hydrogen-2

1513

111H

V

4

Complete the table:

Element Electron Configuration

Orbital Notation

Electron Dot

Beryllium

Sn (No Orbital Notation)

S

1s2 2s2

Write the noble gas configuration for krypton. Also, draw the electron dot diagram.

What shapes are s and p orbitals?

S- Sphere P- Dumbells

Explain, in your own words ground state for electrons.

Explain, in your own words excited state for electrons.

Ground state electrons in the lowest possible energy level are normal.

Excited state electrons take on energy and jump energy levels.

George (the Geko)

Why did the chemicals used in the “somewhere in the rainbow” lab give off colors when heated?

The electrons absorbed the heat from the burner, causing them to jump up to the excited state. In order to return back to “ground state” the electrons must give off the extra energy – in the form of light.

Paris Hilton The Hulkvs.

Consider the electrons found in Sulfur. How many total orbitals are found in sulfur? _______ Of all these orbitals, how many are found on the 2nd energy level? _________ Of the orbitals found on the second energy level, how many different orbital shapes are there? _________ How many electrons could fit into the entire 2p sublevel? ______ How many electrons could fit into one 2p orbital? ___________

9

4

26

2

Titanium has 5 naturally occurring isotopes. Calculate the average atomic mass.

Sodium has two isotopes. Sodium-22 and Sodium-23. Which is more abundant? ________________

Mass (amu) % Abundance

45.955 8.00

46.952 7.30

47.948 73.80

48.948 5.50

49.945 5.40

Sodium-23