U1C1 Flashcards
What was john daltons atomic theory
All matter is made up of tiny particles called
atoms. An atom cannot be created, destroyed
or divided into smaller particles
The atoms of one element cannot be converted
into the atoms of any other element
All the atoms of one element have the same
properties, such as mass and size. These
properties are different from the properties of
the atoms of any other element
Atoms of different elements combine in specific
proportions to form compounds
What did JJ Thomson contribute to atomic theory
Thomson studied the
passage of an electric
current through a gas.
As the current passed through the gas,
it gave off rays of negatively charged
particles.
Describe the thomson model
Positively charged matter with electrons throughout it
What did eugen goldstein contribute to atomic theory
Discovered the proton using cathode rays colliding with neutral gas
what did hantaro nagakoa contribute to the atomic theory
The saturnian system (positively charged matter, surrounded by electrons)
What did Ernst Rutherford contribute to atomic theory? using what experiemnt?
He discovered the nucleus using the gold foil experiment
What did james chadwick contribute to atomic theory
He discovered neutrons by hitting Be with alpha particles. The beam wasnt affected by magnets.
What did Niels Bohr contribute to atomic theory
Electrons exist in circular orbits (planetary orbits) with
electrostatic force from the nucleus holding them in
place
Electrons can exist in only a series of allowed orbits
(energy levels). Therefore the energy of electrons are
quantized
While an electron is in one orbit it does not radiate
energy
Electrons can “jump” between energy levels by
absorbing and emitting photons (packets of energy)
carrying an amount of energy that equals the
difference in the energy levels of electrons
According to the Bohr model, what are the two ways an atom can be excited?
- Atom can collide with a
highly energetic particle (e.g.
electron) in an electric current
passing through a gas - Atom can absorb a photon
that has an amount of energy
equal to the difference
between the energy of the
orbit it occupies and the
energy of a higher orbit
What are line spectra
A line spectra is a series of coloured lines with dark space in between (or vice versa)
How are line spectra formed (emission)
A gas discharge tube containing an element goes through two small slits and into a prism. This will split the light and display which colours are emitted by the gas.
Charge, symbol, location and relative mass of each subatomic particle
neutron - 0 - n0 - nucleus - 1
proton - +1 - p+ - nucleus - 1
electron - -1 - e- - orbit - 1/2000
How to write standard atomic notation
Large element symbol, to the left of it make the top number the mass# and the bottom the atomic#
What happens to wavelength when energy increases
wavelength gets shorter
What are the colours of light from least to most energy
reds
oranges
yellows
greens
blues
violets
How does electron movement in an atom effect colour of light
The longer distance the electron moves, the more energy is produced. A far movement would create violet light, a short one would create red light.
What is required for an atom to be stable
full valence shell (stable octet)
What is isoelectronic
two atoms or ions that have the same electronic structure and same number of valence electrons.
What is an isotope
A variation in mass of an atom of an element due to a difference in neutron count
what is isotopic abundance
the % or decimal amount of quantity an isotope has compared to other isotopes
what is average atomic mass (AAM)
Average atomic mass is the average mass of an atom based off how abundant its isotopes are
Formula for Average atomic mass (AAM)
AAM = %ab1 x mass1 + %ab2 x mass2…
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what is a radioisotope
radioactive isotope
How is radiation produced, what is radiation?
Radiation is produced from decaying atoms. radiation is the emission or transmission of energy in the form of waves or particles.
what are the 3 types of radiation, their symbols, and penetrating power
alpha particles - fancy curved a - wont penetrate skin
beta particles - funny long stick B - will penetrate skin and some tissues
gamma rays - LONG Y - will deeply penetrate tissue
what is a group, period and family
group - vertical column
period - horizontal row
family - ways to divide certain elements in the periodic table (alkali metals, halogens, etc.)
properties of metals
malleable, ductile, good conductors, lustrous, solids at room temp (except mercury), typically tough
properties of non metals
non malleable, not ductile, poor conductors, not lustrous, brittle or soft, can be any state at room temp,
properties of metalloids
lustrous, brittle, mid conductors, some are malleable, some are ductile
what did johann dobereiner contribute to the periodic table
law of triads - groups of three elements with similar properties. Put three elements in order of atomic weight
what did john a. newlands contribute to the periodic table
Arranged all known elements in order of atomic mass. Observed every 8th element had similar properties (law of octaves). began to use families.
what did dimitri medeleev controbute to the periodic table
Organized elements by atomic masses that were arranged “periodically” with elements of similar properties under each other
what is effective nuclear charge, what is its short form, how does it affect periodic trends
Effective nuclear charge is how much pull the protons in the nucleus have on the electrons (net force), shortened to Zeff. Zeff increases from left to right on the table, making the atomic radius smaller.
what are the trends in atomic radius
from left to right atomic radius decreases, from up to down it increases
what happens to atomic radius to a metal and non metal when an ion is formed
A metal’s radius decreases, a non metals radius increases
what are the trends in ionization energy
Ionization energy increases from left to right, decreases top to bottom
what is the chemical equation for ionization energy, use sodium as an example
Na (g) + energy -> Na+ + e-
what is atomic radius
Atomic radius is generally stated as being the total distance from an atom’s nucleus to the outermost orbital of electron.
what is ionization energy
Ionization energy, in chemistry and physics, the amount of energy required to remove an electron from an isolated atom or molecule.
what is electron affinity
The energy change that occurs when an electron is addedto a neutral, gaseous atom to form an anion
what are the trends in electron affinity
increases left to right, decreases top to bottom (same as ionization)
what is the chemical equation for electron affinity, use flourine as an example
F(g) + e- -> F-(g) ∆energy
what is electronegativity
The ability of an atom to attract the shared electrons towards itself in a bond
what is the trend in electronegativity
increases left to right, decreases top to bottom (same as ionization)
