Chapter 1.1: Electronic Structure of Atoms Flashcards
What is the spreading of electron density over a large volume of space?
delocalization
Define valence electrons
electrons in the valence (outermost) shell of an atom
Define ionization potential
the energy needed to remove the most loosely held electron from an atom or molecule
What is the outermost occupied electron shell of an atom?
valence shell
Define orthogonal
having no net overlap
What is the symbol of an element surrounded by a number of dots equal to the number of electrons in the valence shell of the atom?
Lewis Dot Structure
What is the ability to do work?
energy
What does Hund’s Rule state?
• Hund’s Rule states that when orbitals of equal energy are available but there are not enough electrons to fill all of them completely, one electron is put in each before a second electron is added to any
What states that when orbitals of equal energy are available but there are not enough electrons to fill all of them completely, one electron is put in each before a second electron is added to any?
Hund’s Rule
Define quantization
having specific values for energy and momentum
Define shells
a region of space around a nucleus that can be occupied by electrons, corresponding to a principle quantum number
Define energy
the ability to do work
What does the Pauli Exlusion Principle state?
• The Pauli Exclusion Principle states that no more than two electrons may be present in an orbital. If two electrons are present, their spins must be paired
What does an atom consist of?
• An atom contains a small, dense nucleus made of neutrons and positively charged protons
o Nucleus surrounded by negatively charged electrons
Define delocalization
the spreading of electron density over a large volume of space
What is the energy that can be released if given an opportunity?
potential energy
Define Ground-State Electron Configuration
the lowest energy electron configuration of an atom or molecule
Define excited state
a state of a system at higher energy than the ground state
What are electrons in the valence (outermost) shell of an atom?
valence electrons
Define ground state
the lowest energy state of a system
What is Golden Rule #1?
o Golden Rule #1: In most stable molecules, the atoms have filled valence shells
What is having no net overlap?
orthogonal
What does the Aufbau Principle state?
• The Aufbau Principle states that orbitals fill in order of increasing energy, from lowest to highest
What is the energy needed to remove the most loosely held electron from an atom or molecule?
ionization potential
Define Lewis Dot Structure
the symbol of an element surrounded by a number of dots equal to the number of electrons in the valence shell of the atom
What states that no more than two electrons may be present in an orbital. If two electrons are present, their spins must be paired?
The Pauli Exclusion Principle
What is a region of space that can hold two electrons?
orbital
What is the lowest energy state of a system?
ground state
What is having specific values for energy and momentum?
quantization
What is a region of space around a nucleus that can be occupied by electrons, corresponding to a principle quantum number?
shells
Define potential energy
the energy that can be released if given an opportunity
What is a state of a system at higher energy than the ground state?
excited state
How many electrons can each shell hold?
2n^2, where n is the number of the shell
What is the most important question in Organic Chemistry?
Where are the Electrons?
What are the 3 rules the determine the ground-state electron configuration?
- The Aufbau Principle
- The Pauli Exclusion Principle
- Hund’s Rule
What states that orbitals fill in order of increasing energy, from lowest to highest?
The Aufbau Principle
What is the lowest energy electron configuration of an atom or molecule?
ground-state electron configuration
What is the relationship between shell number of electron energy?
Higher shell number = more electron energy
What are the 3 effects of quantized electron energy?
• 3 effects: electrostatic attraction that draws the electrons toward the nucleus; electrostatic repulsion between the electrons; wavelike nature of an electron that prefers to be delocalized, thereby spreading the electron density away from the nuclei
Define valence shell
the outermost occupied electron shell of an atom
Define orbital
a region of space that can hold two electrons
