History of Atom- Chemistry TEST
Short hand electron for (Cd)
(Kr)5s²4d¹⁰
Quantum number at ground state
1
Dalton's Atomic Theory (John Dalton)
1) elements are composed of atoms. 2) atoms of same element are identical, but differ from other elements. 3) elements can mix together 4) atoms only change when mixed with other elements
an electrically neutral atom of arsenic has
33 protons, 33 electrons
Gold Foil Experiment (Ernest Rutherford)
Conducted by Ernest Rutherford in which alpha particles that were shot at gold foil were deflected when they hit the positive center of gold atoms. The nucleus was discovered as a result of this experiment.
element that is an exception to the aufbau principle
Copper (Cu)
CMYK (also made by reflection) (pigments)
Cyan, Magenta, Yellow, Black
James Chadwick
Discovered the neutron. unchanged particle
Wavelength
Distance between the crests
what can be concluded from the research of Louis De Broglie
Electrons behave as waves
Where does light come from?
Electrons falling from high energy orbits to low energy orbits.
Democritus
Greek philosopher that said all matter is made of tiny particles called "atomos" or atoms
Atoms have no electric charge because they have
Have an equal number of electrons and protons
Amplitude
Height of a wave
Werner Heisenberg
Heisenberg uncertainty principle
related how alchemy morphed into chemistry
In the beginning the early alchemists thought they could make common items into gold thus increasing their wealth. From the lab we learned that you can make items look like gold but only physically. Common people could be duped into believing those items were real gold
Plum Pudding Model (JJ Thomson)
J.J Thomsons model of an atom, in which he thought electrons were randomly distributed within a positively charged cloud
The electron was discovered in 1897. Who discovered it?
JJ Thomson
In 1808, who was the Quaker teacher that challenged Aristotelian theory with his own Atomic Theory?
John Dalton
who didn't wash their hands when prepping food, causing many to get sick and die
Mary "Typhoid Mary" mallon
Who stipulated that electrons orbit the nucleus at fixed energies and distances?
Niels Bohr
light can travel through a vacuum, but a wave can't. So light must be a ____
Particle
what color does lithium emit
Red
Erwin Schrodinger (1926)
Schrodinger Wave Equation. developed an equation that treated electrons in atoms as waves
Marie Curie
She said that radioactivity had nothing to do with how atoms are arranged into molecules. shared elements that emitted radiation
why is the mass number larger than the atomic number
The atomic mass is not equal to the atomic mass number because of isotopes.
compare the size and density of an atom with its nucleus
The nucleus is the tiny central core of the atom and is made up of protons and neutrons (more dense). The atom is larger and less dense (mostly empty space/ electrons).
Louis De Broglie
Theory of Electron Waves. properties of waves offered an explanation to an atoms restricted motion
How is light emitted from electrons?
When excited, an electron moves to a higher energy level or orbital. When the electron falls back to its ground level the light is emitted.
the mass of a neutron is
about the same as that of a proton
which part of daltons atomic theory no longer agree with the current picture of the atom
all elements are indivisible because atoms can be broken into protons
ROY G BIV
as you move right light gains energy, waves become smaller.
neutron
atomic # - mass
refract
bend
what color do pigments that absorb color look like?
black
strontium chloride
bright red
magnesium
bright white light
speed of light
c= 3x10⁸ m/s
a prism separates light by _____
dispersion
What are pigments
dyes that color paints, inks, and even food. they produce reflection.
During the flame test, crystals of a compound are passed through the Bunsen burner flame. the flame turns a bright red color. What can be concluded from this red color?
electrons are moving slow, producing a giant wave length
EM Spectrum
gamma ray, x-ray, ultraviolet, visible, infrared, microwave, radio
During a flame test, what color does copper emit?
green
iron chloride
green/yellow sparkles
What is the name for the lowest , most stable energy state of an atom
ground state
lithium chloride
hot pink
A banana reflects yellow light so ____
it absorbs all other colors
which of the following best describes the Heisenberg uncertainty principle
it is impossible to know both the velocity and location of an electron at the same time
sodium chloride
light/bright orange
Electron Cloud Model
model of atom in which the electrons seem to form a cloud as they move around the nucleus
Bohr Model (Niels Bohr)
model of the atom in which electrons move rapidly around the nucleus in paths called orbits
electron
negative charge (mocks # of protons)
location, size, charge for electron
negative, 1/200th of a proton, outside nucleus
location, size, charge for neutron
no charge, almost 1amu, in nucleus
Most of the mass of an atom is located in the ___________.
nucleus
most of the mass of an atom is located in the
nucleus
calcium chloride
orange
Soon after Bohr's planetary model took center stage, experiments showed that electrons behaved _____
particles and waves
a light packet is called a
photon
potassium chloride
pinkish purple (light color)
proton
positive charge (mocks atomic #)
Location, size, charge for proton
positive, 1amu, in nucleus
Atoms of each element contain a unique number of ______ in their nuclei, specific to that element
protons
Which color of the visible light spectrum has the most energy?
purple
what color mixture makes white?? (primary colors) (the colors computers and tvs use)
red, blue, green (RGB)
RGB (lights)
red, green, blue
Who is credited for the gold foil experiment
rutherford
from his Gold foil experiment, Rutherford concluded that
the atom has a dense positive center
What did the gold foil experiment discover?
the nucleus is positively charged
Frequency
the number of wave cycles to pass a given point per unit of time
What does the mass number tell you?
the total number of protons and neutrons in the atom
what is the electron cloud like
used to describe where electrons are when they go around the nucleus of an atom
light is a
wave
How is the number of electrons related to the number of protons
when the atom is neutral (not an ion), they are the same
what color do pigments that reflect color look like?
white
where do different colors come from?
white sunlight, each of these colors has its own frequency, wavelength, and energy. (a prism can separate white light into all of its colors.)