Unit one Flashcards
What is the difference between a law and theory
a law describes an observation while a theory explains an observation
what questions do law and theories answer
laws answer what happened while theories answer why or how
what is the law of conservation
mass is neither created or destroyed
what is the law of definite proportions and what is another name for it
a substance is always made of the same proportions of elements; law of constant composition
what is the law of multiple proportions
elements combine in small, whole number ratios
what is Dalton’s atomic theory
matter is made of small, indivisible particles; atoms of a particular elements are identical; atoms of differnet elements are different; atoms combine in small, whole number ratios; atoms are neither created or destroyed
What is the mass defect effect
energy is lost due to the effort it takes to smoosh protons into nucleus thus the atomic weight of an atom is less than expected
what is the atomic number and how is it found
number of protons in an element; found on the periodic table
what is the mass number and how is it found
protons plus neutrons, found by calculation
what is an isoptope
atoms of the same element with different number of neutrons
what are ions
atoms that are not neutral due to different number of protons and electrons
what is the atomic mass
weighted average based on natural abundance of isotopes
what is the molecular formula
exact number of atoms in molecules
what is the empirical formula
ratio of atoms in a molecule
what is the symbol for wavelength and what does it mean
λ meaning the distance between any given point and the same point in the next wave
what is amplitude
the intensity of the waves
what is the symbol for frequency and what does it mean
v; how often there are waves per second
energy is _____ to v
proportional
energy is _____ to λ
inversely proportional
λ and v are _____
inversely proportional
how does energy leave an object
as light (in wavelengths)
how does matter differ from gasses in terms of light
matter can exist at all stages of the visible spectrum but gasses can only exist at certain stages
what is work function and its symbol
the E of a photon necessary to remove electrons from metal; Φ
what happens when an electron drop an energy level
a photon is emitted by the atom
what is the uncertaintly principle
it is impossible to simultaenously know the exact position and momnetum of a microscopic particle
what is an atomic orbital
where electrons are likely to be found for each quantum state
What is the principle quantum number, what does it describe, and what can it be
n; describes shells and the distance of electrons from the nucleus; anywhere from 1 to infinity
what is the angular momentum quantum number symbol, what is its significance, what can it be, and what is its relationship with n
l; describes an orbital’s shape; and can be 0-3 or spdf; will always be less than n
what are nodes
areas where electrons will never be found
how do you find tha number of nodes in a subshell
n-1
how do you find the number of angular or planar nodes in a subshell
l
how do you find the number of radial or speherical nodes in a subshell
n-l-1
what is the magnetic quantum number, what does it describe, and what can it be
m sub l; describes the number of orbitals in each subshell; can be 1,3,5 or 7
what is the pauli exclusion principle
no 2 electrons in one atom may have any identical set of quantum numbers (electrons have to be different to be in the same subshell
What is the aufbau principle
electrons in a ground state atom occupy the lowest energy orbitals available to them
what is shielding
Happens when there are multiple electrons in an atom where they will be attracted to the nucleus but repeled from each other causing them to have much lower charge than expected and be held onto less resulting in them having higher energy
What is the trend for shielding
Increases as you go right and down
How does shielding affect orbitals
It causes lower orbitals to be more stable than higher ones
what is the first l block anomaly
it is more stable for d orbitals to be half or fully filled so electrons will be taken away from s orbitals to fulfill this
what does it mean for fluorine to be isoelectronic to helium
that when fluorine gains an electron it has the same electron configuration as helium
what is the second l block anomaly
when losing electrons, d block elements will lose s electrons before losing d ones
What is the effective molecular charge (Z effective) trend
as n and Z increases, Z effective increases
what is Z effective
the net positive charge that an electron feels
What do periodic trends depend on and how do they increase
Z and n; n increases down the periodic table while Z increases across the period table
what is the atomic radius trend
as n increases, radius increases and as Z increases, radius decreases
What is the ion radius trend
As Z effective increases, ion radius decreases (cations get smaller as they get more positive while anions get larger as they get more negative)
What is ionization energy
The E required to completly remove an electron from an atom
what is the Ionization energy trend
as n increases, IE decreases and as Z increases, IE increases
How are ionization energy and atomic radius related
as atomic radius decreases ionization energy increases
What is electron affinity
E releases when an electron is added to an atom
What is the electron affinity trend
As Z increases, EA increases and as n increases, EA decreases
