Show:
Electron Configurations
Average Atomic Mass
Isotopes
Inside the Atom
Project Runway--All the Models
100
What does Aufbau's principle tell us?
Electrons will fill the lowest energy levels first (start from the bottom)
100
What is the average atomic mass of Thorium (Th)
232.0377
100
What is an isotope?
An isotope is an element with the same number of protons as another element but different number of neutrons
100
In the element Si-30, what does the 30 represent in terms of protons, neutrons, and electrons?
30 is the number of protons + the number of neutrons.
100
Explain how Rutherford discovered the nucleus of an atom
Rutherford shot alpha particles, which are positive particles, at a piece of gold film (foil). Most of the particles just passed through without much deflection, but a small few bounced straight back at him. There must have been a concentration of positive charge in the center of the atom since like charges repel.
200
Write the electron configuration for Oxygen (O)
1s2 2s2 2p4
200
Where do you find the average atomic mass on the periodic table?
Beneath the symbol/name for the element
200
Are Ni-59 and Ni-60 isotopes?
Yes
200
What is the atomic number of an atom or element?
The number of protons that element contains.
200
What instrument did Thomson use to discover the electron?
A cathode ray tube
300
What is the purpose of writing electron configurations?
To show in which orbital and at which level the electrons reside in the Schrodinger model of the atom.
300
Explain how to calculate the average atomic mass of an element given different isotopes of the element, the atomic masses of the isotopes, and the percent abundances of the isotopes.
Convert the percent abundances to decimals. Multiply the decimals by the respective atomic masses. Add the products of the multiplication
300
Show 3 different ways you can represent the isotope of carbon that has mass number 14.
Carbon-14, C-14, 14 C, 14 6 C (see what's written on the board)
300
Name the 3 subatomic particles and the charge of each one.
Protons--positive Neutrons--neutral (no charge) Electrons--negative
300
Draw and name 3 of the 5 models of the atom
Any three of Dalton (Atomic Theory), Thomson (Plum Pudding), Rutherford (Nuclear Theory), Bohr (Solar System), Schrødinger
400
Which element has the electron configuration 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p3
Antimony (Sb)
400
Is it possible for an isotope of Gold (Au) to have a mass number of 75? Explain why or why not.
No. The mass number is found by adding the number of protons and the number of neutrons. But Gold (Au) must have at least 79 protons.
400
Draw the Bohr models for P-31 and P-32
Both should have 15 protons and electrons. P-31 should have 16 neutrons. P-32 should have 17 neutrons
400
5 protons, 12 electrons, and 9 neutrons get together at a party. What is their overall charge?
5 - 12 + 0 = -7
400
Explain the difference between Bohr's model of the atom and Schrodinger's model
Bohr--electrons orbit the nucleus in defined circles like a solar system Schrodinger--electrons have high probabilities of being found in various shaped orbitals at any given time
500
Write the electron configuration for Titanium (Ti). Hint: The 3d orbital is at a lower energy level than the 4p orbital, but a higher level than the 4s orbital
1s2 2s2 2p6 3s2 3p6 4s2 3d2
500
Suppose 3 naturally occurring isotopes of an element have atomic masses of 133.904490, 129.906277, and 131.905042. Which of the following could be the average atomic mass of the element? A) 129.8045 B) 132.4178 C) 133.9121
B) Because this is the only number in between the lowest and highest of the atomic masses
500
There are 7 naturally occurring isotopes of Gadolinium (Gd). The percent abundances of 6 of them are 0.200%, 2.18%, 14.8%, 20.47%, 15.65% and 24.84% What is the percent abundance of the 7th?
21.86% = 100% - (0.200+2.18+14.8+20.47+15.65+24.84)%
500
8. Which statement best describes the nucleus of an aluminum atom? (1) It has a charge of -13 and is surrounded by a total of 10 electrons. (2) It has a charge of -13 and is surrounded by a total of 13 electrons. (3) It has a charge of +13 and is surrounded by a total of 10 electrons. (4) It has a charge of +13 and is surrounded by a total of 13 electrons.
(4) It has a charge of +13 and is surrounded by a total of 13 electrons.
500
Explain how each of the five models added to our understanding of the atom. You should do this chronologically.
Dalton--the atom is the smallest, indivisible unit of matter Thomson--atom's contain smaller particles called electrons Rutherford--an atom is mostly empty space with a dense center (nucleus) of net positive charge Bohr--electrons are arranged in shells like orbits in a solar system Rutherford--electrons are arranged in orbitals of probability around the nucleus