Chem 1B Questions and Answers Already Passed Rated 100%
What are periodic properties? - Answers-properties whose values can be predicted based on the
element's position on the periodic table
What is the basis for the transmission of nerve signals? - Answersmovement of ions across cell
membranes
In what directions are Na+ and K+ ions pumped across membranes through ion channels? - AnswersNa+
moves OUT
K+ moves IN
How do we represent orbitals? - Answers-represented as a square and the electrons in that orbital as
arrows.
-the direction of the arrow represents the spin of the electron
What is electron configuration? - Answers-describes how the electrons are distributed in the various
atomic orbitals.
What is the Pauli exclusion principle? - Answers-No two electrons in an atom can have the same four
quantum numbers
What does each electron in a multielectron atom experience? - Answers-both the attraction to the
nucleus and and the repulsion by other electrons in the atom.
What is the effective nuclear charge? - Answers-total amount of attraction that an electron feels for the
nucleus
What happens when the electrons are closer to the nucleus? - Answers-the more attraction it
experiences
The better an outer electron is at penetrating through the electron cloud of inner electrons... - Answers-
the more attraction it will have for the nucleus
What is the Aufbau Principle? - Answers-states that electrons are added to the lowest energy orbitals
first before moving to higher energy orbitals
What is Hund's rule? - Answers-The most stable arrangement of electrons is the one in which the
number of electrons with the same spin is maximized
-put one electron in each before pairing.
What are the general rules for writing electron configurations? - Answers1. electrons will reside in the
available orbitals of the lowest possible energy
2. each orbital can accommodate a maximum of two electrons.
, 3. electrons will not pair in degenerate orbitals if an empty orbital is available
4. orbitals will fill in the order indicated in the figure.
How can electron configurations of all elements except hydrogen and helium be represented? -
Answers-noble gas core
What are the valence electrons? - Answers-the outermost electrons of an atom
What are core electrons? - Answers-electrons in lower energy shells.
What are the the main group elements? (representative elements) - Answers-elements in Groups 1A
through 7A
What group are the noble gases? - Answers-Group 8A
-have completely filled p sub shells.
What group are the transition metals? - Answers-groups 3-12
What make up the f-block transition elements? - Answers-lanthanides and actinides
What is the effective nuclear charge (Z-eff) -lecture 2? - Answers-The actual magnitude of positive
charge that is "experienced" by an electron in the atom.
How does the value of the effective nuclear charge increase? - Answers-increases steadily from left to
right
What is the atomic radius? - Answers-distance between the nucleus of an atom an its valence shell
How does the atomic radius increase? - Answers-increases from top to bottom down a group.
-increasing n, so outermost shell lies farther from the nucleus.
How does the atomic radius decrease? - Answers-left to right across a period
-increasing Z-eff which draws the valence shell closer to the nucleus
What is the ionization energy (IE)? - Answers-minimum energy required to remove an electron from an
atom in the gas phase.
-results in an ion, a chemical species with a net charge.
Na(g)-->Na+ (g) + e-
What happens to the ionization energy as the Z-eff increases? - Answers-ionization energy increases
What are periodic properties? - Answers-properties whose values can be predicted based on the
element's position on the periodic table
What is the basis for the transmission of nerve signals? - Answersmovement of ions across cell
membranes
In what directions are Na+ and K+ ions pumped across membranes through ion channels? - AnswersNa+
moves OUT
K+ moves IN
How do we represent orbitals? - Answers-represented as a square and the electrons in that orbital as
arrows.
-the direction of the arrow represents the spin of the electron
What is electron configuration? - Answers-describes how the electrons are distributed in the various
atomic orbitals.
What is the Pauli exclusion principle? - Answers-No two electrons in an atom can have the same four
quantum numbers
What does each electron in a multielectron atom experience? - Answers-both the attraction to the
nucleus and and the repulsion by other electrons in the atom.
What is the effective nuclear charge? - Answers-total amount of attraction that an electron feels for the
nucleus
What happens when the electrons are closer to the nucleus? - Answers-the more attraction it
experiences
The better an outer electron is at penetrating through the electron cloud of inner electrons... - Answers-
the more attraction it will have for the nucleus
What is the Aufbau Principle? - Answers-states that electrons are added to the lowest energy orbitals
first before moving to higher energy orbitals
What is Hund's rule? - Answers-The most stable arrangement of electrons is the one in which the
number of electrons with the same spin is maximized
-put one electron in each before pairing.
What are the general rules for writing electron configurations? - Answers1. electrons will reside in the
available orbitals of the lowest possible energy
2. each orbital can accommodate a maximum of two electrons.
, 3. electrons will not pair in degenerate orbitals if an empty orbital is available
4. orbitals will fill in the order indicated in the figure.
How can electron configurations of all elements except hydrogen and helium be represented? -
Answers-noble gas core
What are the valence electrons? - Answers-the outermost electrons of an atom
What are core electrons? - Answers-electrons in lower energy shells.
What are the the main group elements? (representative elements) - Answers-elements in Groups 1A
through 7A
What group are the noble gases? - Answers-Group 8A
-have completely filled p sub shells.
What group are the transition metals? - Answers-groups 3-12
What make up the f-block transition elements? - Answers-lanthanides and actinides
What is the effective nuclear charge (Z-eff) -lecture 2? - Answers-The actual magnitude of positive
charge that is "experienced" by an electron in the atom.
How does the value of the effective nuclear charge increase? - Answers-increases steadily from left to
right
What is the atomic radius? - Answers-distance between the nucleus of an atom an its valence shell
How does the atomic radius increase? - Answers-increases from top to bottom down a group.
-increasing n, so outermost shell lies farther from the nucleus.
How does the atomic radius decrease? - Answers-left to right across a period
-increasing Z-eff which draws the valence shell closer to the nucleus
What is the ionization energy (IE)? - Answers-minimum energy required to remove an electron from an
atom in the gas phase.
-results in an ion, a chemical species with a net charge.
Na(g)-->Na+ (g) + e-
What happens to the ionization energy as the Z-eff increases? - Answers-ionization energy increases
