GenChem1 (AtomStructure) Flashcards
Electrons exist outside the nucleus in characteristic regions of space called
orbitals
All atoms of an element cannot be broken down further by ________ means
chemical
What is the mass of 1 proton?
1 amu
Z represents what aspect of an element?
Atomic number
What is the atomic number of an element?
The # of protons
All atoms of a given element have the same
Atomic number
What is the mass of one neutron?
Slightly more than 1amu (more than a proton)
What is the mass number of an atom?
The # of protons + neutrons
A represents what aspect of an element?
Mass number
The electrons furthest from the nucleus are known as
Valence Electrons
The farther electrons are from the nucleus, the STRONG/WEAKER the attractive force of the positively charged nucleus is?
Weaker
Generally speaking, what determines the reactivity of an atom?
Valence electrons
Determine the number of protons. neutrons, and electrons in a Nickel-58 atom and a Nickel 60 2+ cation?
The atomic number of Nickel is 58
Nickel 58 –> 28 protons, 28 electrons, 30 neutrons
Nickel 60 2+ –> 28 protons, 26 electrons, 32 neutrons
The atomic mass of an atom is the relative mass of that atom compared to the mass of a…
What is the standard assigned mass of it?
Carbon-12 atom
12.000amu
One amu is one twelfth the mass of the carbon 12 atom, approximately
1.66*10^-24 (g)
Atomic weight is the….
weight of an atom in grams per mole
One mole is equal to how many particles?
6.022*10^23 particles
6.022*10^23 carbon atoms weighs
12.0g
What is an isotope
Atoms with the same number of protons but different numbers of neutrons
Are the chemical properties of isotopes similar to the non-isotope form? Why?
Yes. They have the same number of protons and electrons.
The energy value of a quantum (E) is equal to…
hf
h =
6.62610^-34 Js
Bohr’s model, based upon Rutherford’s findings, assumed that in the hydrogen atom there was a central proton around which an electron traveled in what type of motion?
Circular Orbit
What is the equation for angular momentum in Bohr’s theory?
nh/2π
Bohr equated the allowed values of angular momentum to the energy of the electron and got what equation?
E= - R(H)/n^2
Energy of the electron changes in discrete amounts with respect to the quantum number!
R(H) =
2.18*10^-18 J/electron
A smaller radius means higher or lower energy state of an electron?
What is the lowest energy state of an electron called (n=1)
Lower
Ground State
The electromagnetic energy of emitted photons from an atom returning to the ground state from an excited state is…
E=hc/λ
Each element can have its electrons excited to distinct energy levels, so each atom possesses a unique
Atomic Emission Spectrum
Wavelength of light emitted from a star can be used to determine what elements it comprises by resolving the star’s component
Wavelengths
The group of hydrogen emission lines corresponding to transitions from n>2 to n=2 is known as the
Balmer Series
The group of hydrogen emission lines corresponding to transitions between upper levels n>1 to n=1 is known as the
(higher energy transitions that occur in the UV region)
Lyman Series
The energy associated with a change in the euantum number from an initial value to a final value is equal to the energy of Planck’s emitted photon. What is the equation that represents this?
E=hc/λ = -R(H)(1/ni^2 - 1/nf^2)
In addition to an emission spectrum, this is formed when an electron is excited to a higher energy level and is characteristic of each element.
Absorption Spectrum
Are the wavelengths of the absorption and emission spectrum the same?
Yes.
Bohr’s model offered a reasonable explanation for the structure of the hydrogen atom but does not explain structures of atoms containing more than 1 electron. Why?
Bohr’s model does not take repulsion between multiple electrons surrounding one nucleus into account
State the Heisenberg uncertainty principle
It is impossible to determine with perfect accuracy both the momentum and position of an electron simultaneously.
If one is measured,the other will change, and vice versa
Bohr’s model also incorrectly assumed that electrons move in circular orbits. What is correct?
Electrons move in orbitals
This states that no two electrons in a given atom can possess the same set of four quantum numbers.
Pauli Exclusion Principle
The position and energy of an electron is described by quantum numbers, also called its
Energy state
The principal quantum number is letter…
The angular momentum quantum number is letter…
The magnetic quantum number is letter…
The spin quantum number is letter…
n
l
ml
ms
The maximum number of electrons in an energy level n is…
2n^2
The energy difference between the third and fourth shells is more or less than that between the second and third shells?
Less
For any given n, the value of l can be any integer in the range of..
l refers to the ____ that occur within each principal energy level
0 to n-1
subshells/sublevels
The maximum number of electrons that can exist in a subshell/sublevel
4l+2
Greater l means greater energy,. However, energies of subshells from different principal energy levels may overlap. For example, 4s will have a higher/lower energy than the 3d subshell
lower.
The average distance of 4s from the nucleus is smaller than 3d
l=0,1,2,3
s,p,d,f subshells
This quantum number designates the particular orbital within a subshell where an electron is highly likely to be found at a given point in time. This orbital can contain no more than 2 electrons
magnetic quantum number (ml)
The possible values of ml are…
-l to +l
The three dumbell shaped orbitals that are oriented around the nucleus are referred to as..
px,py,pz
This quantum number that is the particle’s intrinsic angular momentum.
spin quantum number (ms)
Electrons in the same orbital must have ____ spins
Electrons in different orbitals with the same ms values are said to have ____ spins
Opposite
Parallel
When writing the electron configuration of an atom, it is necessary to remember the order in which subshells are filled. Subshells are filled from lowest/highest energy to lowest/highest energy
Subshells are filled from lowest energy to highest energy
Hand’s Rule states that within a given subshell, orbitals are filled such that there are a maximum number of half-filled orbitals with OPPOSITE/PARALLEL spins?
Hand’s Rule states that within a given subshell, orbitals are filled such that there are a maximum number of half-filled orbitals with PARALLEL spins
According to the book, subshells may be listed in the order in which they fill or with subshells of the same principle quantum number grouped together. Either is correct.
Mmkay.
A material with unpaired electrons that is weakly attracted to magnetic fields because of realignment is called
A material with paired electrons that is not attracted to magnetic fields is called
Paramagnetic
Diamagnetic
If all molecules in a given problem have the appropriate number of protons and neutrons, what else determines their radioactivity?
If they have odd numbers of protons and neutrons
