Chapter 1: Flashcards
(33 cards)
Ground state:
The state of an atom at its lowest energy, where all electrons are in the lowest possible orbitals.
Excited state:
An atom in a state where at least one electron has moved to a subshell of higher than normal energy.
Define effective nuclear charge - Zeff:
The net positive force experience by an electron, determined by the number of protons and the shielding effect by electrons in lower orbitals.
An electron in a 1s orbital would have the highest effective nuclear energy in which of the following elements?
a. H
b. Na
c. Cl
d. O
Cl - Because the Zeff depends on number of protons and shielding by electrons in lower orbitals. Since it is in 1s - the lowest possible oribital - the only thing to consider is protons. Cl has the greatest number of protons - with 17.
What fraction of 125I decays in 180 day, if it’s half life is 60 days?
In 180 days, 3 half lives will occur. So the total amount that will decay is:
1-(1/2)^3 = 7/8
B-decay:
The number of protons decreases by 1.
Gamma decay:
The emission of a high energy photon - does not create a new element.
If Sulfer goes through B-decay twice, and then gamma decay one, what atom will result?
Silicon.
Alpha decay:
An atom loses two protons and two neutrons.
If arsenic goes through 1 alpha decay and 1 beta decay, what atom will result?
Zn.
Maximum number of electrons in a S subshell:
2
Maximum number of electrons in a P orbital:
6
Maximum number of electrons in a D orbital:
10
Maximum number of electrons in a F orbital:
14
What is the ratio of the maximum number of electrons in an F orbital compared to a D orbital:
14/10
Which of the following is the correct electron configuration for Zn2+:
a. 1s^2, 2s^2, 2p^6, 3s^2, 3P^6, 4s^0, 3d^10
b. 1s^2, 2s^2, 2p^6, 3s^2, 3P^6, 4s^2, 3d^8
c. 1s^2, 2s^2, 2P^6, 3s^2, 3P^6, 4s^2, 3d^10.
a.
Which of the following quantum number sets is possible:
a. n = 2; l = 2; ml = 1; ms = +1/2
b. n = 2; l = 1; ml = -1; ms = +1/2.
c. n = 2; l = 0; ml = -1; ms = - 1/2
d. n = 2; l = 0; ml = 1; ms = -1/2.
b -
1. Azimuthal quantum number (l) cannot be higher than n.
2. ml can only be an integer number between -l and l -
What is the maximum number of electrons allowed in a single atomic energy level in terms of the principal quantum number (n)?
a. 2n
b. 2n + 2
c. 2n^2.
d. 2n^2 + 2
2n^2
Which of the following equations describes the maximum number of electrons that can fill a subshell:
a. 2l + 2
b. 4l + 2
c. 2l^2
d. 2l^2 + 2
4l + 2
Which of the following atoms only has paired electrons in its ground state:
a. sodium.
b. iron.
c. cobalt.
d. helium.
Helium.
What is the proper electron configuration of Ti(2+)?
- 1s^2, 2s^2, 2p^6, 2d^10.
- 1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2.
- 1s^2, 2s^2, 2p^6, 3s^2. 3p^6, 3d^2.
- 1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2, 3d^2.
3 - 1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 3d^2.
This is because neutral Ti has 22 protons and electrons, so Ti2+ must have 20 electrons. Even though on neutral Ti, 4s^2 would come first, when removing electrons, they would remove from the 4 level before the 3 level.
Researchers are interested in discovering new elements to be used as a source of nuclear energy through an alpha decay process. They begin by analyzing Silicon. What is this elements electron configuration.
- 1s^2, 2s^2, 2p^6, 3s^2, 3p^2.
- 1s^2, 1p^6, 1d^6.
- 1s^2, 2s^2, 2p^6, 3s^2, 3p^6.
- 1s^2, 2s^2, 2p^4, 3s^2, 3p^4.
- 1s^2, 2s^2, 2p^6, 3s^2, 3p^2.
Silicon has 14 protons, so neutral silicon would have 14 electrons. #1 is the onyl one that is formatted properly.
How does the angular momentum (azithumal) quantum number (l) relate to the prinicple quantum number (n)?
l = n -1 ALWAYS
An angular momentum (azithumal) quantum number of 0 corresponds to what type of oribital?
A spherical S oribital
