Chemistry sections 5.1 and 5.2 test
orbitals? 2s sublevel
1
how do you find the amount of electrons
2n^2
when electrons occupy orbitals of equal energy, one electron enters each orbital until all the orbitals contain one electron with parallel spins.
Hund's rule
After the discovery of the electron by ________, the atomic model was revised to include them.
JJ Thomson
The first modern atomic theory, proposed by _________, portrayed the atoms as a solid, indivisible mass.
John Dalton
AT, ST, or NT: As many as four electrons can occupy the same orbital.
NT
AT, ST, or NT: The configuration 3d^4 4s^2 is more stable than the configuration 3d^5 4s^1
NT
AT, ST, or NT: The number of sublevels in an energy level is equal to the square of the principal quantum number of that energy level.
NT
the _______ describes the sequence in which orbitals are filled.
aufbau principle
what are the three rules for writing the electron configurations of elements
aufbau principle, pauli exclusion principle, and hunds rule
Why do actual electron configurations for some elements differ from those assigned using the aufbau principle?
because half-filled sublevels are not as stable as filed ones, but they are more stable than other configurations
Why does one electron in a potassium atom go into the fourth energy level instead of squeezing into the third energy level along with the eight already there?
because the outer shell can only have 8 electrons
Correct electron configurations can be obtained by using the Aufbau diagram for the elements up to and including vanadium. __________and copper are exceptions to the Aufbau principle.
chromium
In the Bohr model, the electrons move in _______ paths.
circular
historical summary of the atomic theory
dalton says atoms are tiny, indestructible particles. thomson discovers electron. rutherford finds that atom has small, dense, positively charged nucleus. Bohr's model- electron moves in circular orbit at fixed distances from nucleus. Shrodinger develops mathematical equations to describe motion of electrons in atoms which led to quantum mechanical model. Chadwick confirms electrons and atomic nuclei contains neutrons and positively charged protons.
What does the quantum mechanical model determine about the electrons in an atom?
determines the allowed energies an electron can have and how likely it is to find the electron in various locations in the nucleus
the most stable arrangement of electrons around the nucleus of an atom
electron configuration
The ways in which electrons are arranged around the nuclei of atoms are called __________.
electron configurations
The chemical properties of atoms, ions, and molecules are related to the arrangement of the __________ within them.
electrons
How can electrons in an atom move from one energy level to another?
electrons make quantum leaps by gaining or losing precise amounts of energy
What is a region in space around the nucleus of an atom where an electron is likely to be moving?
energy level
The various orbitals within a sublevel of a principle energy level are always of _______ energy
equal
What is the Pauli Exclusion Principle?
max of 2 electrons in an orbital
how do you find orbitals
n^2
1s^2 2s^2 2p^6
neon
Rutherford pictured the atom as a dense _____ surrounded by electrons
nucleus
Hund's rule states that the electron pair up only after each orbital in a sub level is occupied by _______.
one electron
To occupy the same orbital, two electrons must have ______ spins.
opposite
The ______ principle states that a maximum of only ______ electrons can occupy each orbital.
pauli exclusion; 2
J.J Thomson's model is referred to as the ________ model.
plum-pudding model
This model estimates the ________ of finding an electron within a certain volume of space surrounding the nucleus.
probability
what is the amount of energy required to move an electron from its present energy level to the next higher one
quantum
The _____ model is the modern description of the electrons in atoms.
quantum mechanical
what is the modern description of the behavior of electrons in atoms
quantum mechanical model
How do two sublevels of the same principal energy level differ from each other?
sublevels have different shapes
When using the shorthand method for showing the electron configuration of an atom, ________ are used to indicate the number of _____occupying each sub level.
superscripts; electrons
the energies of electrons are said to be quantized. Explain what this means.
takes a certain amount of energy
electrons enter orbitals of lowest energy first
Aufbau principle
orbitals? 4p sublevel
3
orbitals? 3d sublevel
5
orbitals? 4f sublevel
7
AT, ST, or NT: Electrons must have a certain minimum amount of energy called a quantum in order to move from one energy level to the next higher energy level.
AT
AT, ST, or NT: The Pauli exclusion principle states that an atomic orbital may describe at most two electrons.
AT
AT, ST, or NT: The higher the energy level occupied by an electron the more energetic it is.
AT
AT, ST, or NT: The maximum number of electrons that can occupy the fourth principal energy level of an atom is 32.
AT
AT, ST, or NT: The principal quantum number equals the number of sublevels within that principal energy level.
AT
An atomic orbital may describe at most two electrons
Pauli exclusion principle
AT, ST, or NT: The election probability clouds for atomic orbitals are spherical shape.
ST
AT, ST, or NT: The orbitals of a principal energy level are lower in energy than the orbitals in the next higher principal energy level.
ST
What is Hund's rule?
all orbitals must receive 1 electron before any receive the second one
What was the basic proposal in the Bohr model of the atom?
an electron is found only in specific circular paths, or orbitals, around the nucleus
what are the regions around the nucleus within which the electrons have the highest probability of being found
atomic orbitals