Atomic Structure Flashcards
Protons have a mass of approximately one ______ ______ _______.
Atomic mass unit (amu)
The atomic number (Z) of an element is equal to the number of ______ found in an atom of that element.
Protons
True or false: Together, the protons and neutrons of the nucleus make up almost the entire mass of an atom.
True. The mass of a single electron is negligible.
What is the mass number (A) of an atom?
The sum of the protons and neutrons in an atom’s nucleus.
What are isotopes?
Atoms of the same element that have the same number of protons but different numbers of neutrons.
Do electrons closer to the nucleus have more or less energy compared to electrons farther away from the nucleus?
Less energy
Generally speaking, which electrons of an atom are involved in chemical bonding?
Valence electrons
A positively charged atom is called a _____; a negatively charged atom is called a(n) ______.
Cation; anion
True or false: The atomic mass of an atom (in amu) is essentially the same as its mass number.
True
The weighted average of different isotopes is referred to as atomic ______. It is the number reported on the periodic table.
Weight
What is the numerical value of Avogadro’s number?
6.02 x 10^23
The _____ state of an atom is the state of lowest energy, in which all electrons are in the lowest possible orbitals.
Ground
An atom is said to be in the ______ state when at least one electron has moved to a subshell of higher than normal energy.
Excited
The group of hydrogen emission lines corresponding to transitions from energy levels n = greater than or equal to 2 to n= 1 is known as the ______ series.
Lyman
The group of hydrogen emission lines corresponding to transitions from energy levels n = greater than or equal to 3 to n= 2 is known as the ______ series.
Balmer
The group of hydrogen emission lines corresponding to transitions from energy levels n = greater than or equal to 4 to n= 3 is known as the ______ series.
Paschen
Describe the Heisenberg uncertainty principle.
This principle states that it is impossible to simultaneously determine both the location and the momentum (energy) of an electron with perfect accuracy.
According to the ______ ______ principle, no two electrons in a given atom can possess the same set of four quantum numbers.
Pauli exclusion
What are the 4 quantum numbers that can be used to completely describe an electron?
- n
- l
- m sub l
- m sub s
The first quantum number, the letter n, is commonly known as the _______ quantum number.
Principal quantum number. It can theoretically take on any positive integer value.
The maximum number of electrons within a shell can be determined by what equation?
2n^2
The second quantum number is called the _______ (angular momentum) quantum number and is designated by the letter l.
Azimuthal. It refers to the shape and number of subshells within a given principal energy level.
The value of n limits the value of l in the following way: for any given value of n, the range of possible values for l is 0 to ______?
(n - 1)
What formula determines the maximum number of electrons within a subshell?
4l + 2
The third quantum number is the ________ quantum number. It specifies the particular orbital within a subshell where an electron is most likely to be found at a given moment in time.
Magnetic (m sub l)
The possible values of m sub l are the integers between ____ and ____, including 0.
-l; +l
True or false: Whenever two electrons are in the same orbital, they must have the same spins.
False. Two electrons in the same orbital must have opposite spins. In this case, they are often referred to as being paired.
Electrons in different orbitals with the same m sub s values are said to have _______ spins.
Parallel
The l = 0 subshell is called ____.
s
The l = 1 subshell is called ____.
p
The l = 2 subshell is called ____.
d
The l = 3 subshell is called ____.
f
Describe the shapes of the orbitals in the s and p subshells.
The orbitals in the s subshell are spherical, while the three orbitals in the p subshell are each dumbbell-shaped and align along the x-, y-, and z-axes.
The fourth quantum number is called the _____ quantum number and is denoted by m sub s.
Spin
What are the two spin designations for an electron?
+1/2 and -1/2
Electrons fill from lower- to higher-energy subshells, according the ______ principle (also called the building-up principle).
Aufbau
Electron configurations can be abbreviated by placing the ______ ______ that precedes the element of interest in brackets.
Noble gas
Describe the process for determining the electron configuration of a cation.
- Start with the configuration of the neutral atom.
- Remove electrons from the subshells with the highest value for n first.
- If multiple subshells are tied for the highest n value, then electrons are removed from the subshell with the highest l value among these.
Orbitals fill according to what rule?
Orbitals fill according to Hund’s Rule. This states that, within a given subshell, orbitals are filled such that there are a maximum number of half-filled orbitals with parallel spins.
In terms of electron configuration, what types of orbitals have lower energies (higher stability) than other states?
Half-filled orbitals and fully-filled orbitals are more stable.
Materials consisting of atoms that have only paired electrons will be slightly repelled by a magnetic field and are said to be _______.
Diamagnetic
The valence electrons in Groups IA and IIA (Groups 1 and 2) are located where?
For these groups, the highest s subshell electrons are valence electrons.
What are the valence electrons for Groups IIIA through VIIIA (Groups 13 through 18)?
The highest s and p subshell electrons are the valance electrons for these groups.
In what subshells do we find the valence electrons for transition elements?
Their valence electrons are those in the highest s and d subshells, even though they have different principal quantum numbers.
Where are the valence electrons for elements in the lanthanide and actinide series?
Their valence electrons are those in the highest s and f subshells, even though they have different principal quantum numbers.
In the _____ model of the atom, a dense, positively charged nucleus is surrounded by electrons revolving around the nucleus in orbits with distinct energy levels.
Bohr
The ______ ______ model posits that electrons do not travel in defined orbits but rather are localized in orbitals.
Quantum mechanical
Which type of materials have unpaired electrons that align with magnetic fields, attracting the material to a magnet?
Paramagnetic
