Chemistry Ch 4 Test- Henning
What is an isotope?
Atoms with the same number of protons but different number of neutrons
what element was the model isotope for AMU?
Carbon-12
How did Goldstein discover the proton?
Cathode tube ray experiment
Gold Foil Experiment
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.
Who stated that all atoms of the same element are excactly alike?
Dalton
Solid Sphere Model
Dalton- an atom is little more than a singular, solid particle without other components.
The first person to ever talk about an atom was
Democritus
The first person to propose a theory about an atom was
Democritus
This is a negatively charged particle found outside the nucleus
Electron
Which of the following is proposed by Erwin Schrodinger?
Electron cloud model of the atom
People have always agreed that matter is made of atoms. True or False
False
Neon has an atomic number of 10 and an atomic mass of 20.180. How many protons, electrons, and neutrons will it have?
P=10 E=10 N=10
What was Thomson's model called?
Plum pudding model
Niels Bohr suggested that electrons.......
are found in specific orbits
what did Democritus call the small particles?
atomos
All matter is made of what?
atoms
Place the following scientists in order, from earliest to latest:A) Ernest RutherfordB) J.J. ThomsonC) John Dalton
c,b,a
J.J. Thomson provided evidence that an atom...
contains negatively charged particles
What did Thomson originally call electrons?
corpuscles
what did Thomson originally call electrons?
corpuscles
Quantum Model
current atomic model in which a tiny, dense atomic nucleus is surrounded by a "cloud" of electrons occupying three-dimensional orbitals according to their energies
Contributes basically no mass to an atom
electrons
cathode ray tube
evacuated glass tube in which a stream of electrons emitted by a cathode strikes a fluorescent material, causing it to glow
Some atoms are large enough to see with your eyes. true or false.
false
what was Thomson's contribution to the atomic theory?
found electrons
how did Schrodinger's model contribute ti the atomic theory?
he created the quantum model
what was Rutherfords contribution to the atomic theory?
he discovered the positive piece at the center of the atom (nucleus)
how did Niels Bohr contribute to the atomic theory?
he explained chemical properties by putting electrons in orbit
what was Dalton's atomic theory?
his 4 postulates
Ernst Rutherford discovered which part of the atom through the use of gold foil?
nucleus
This contains most of the mass of an atom
nucleus
This particle is found in the nucleus and has a positive charge
proton
What did Goldstein discover?
protons
What does the nucleus of an atom contain?
protons and neutrons
What was Dalton's model?
solid sphere
Schrodinger
studied energy of electrons and helped develop electron cloud model
Millikan calculated
the mass and charge of the electron
atomic number
the number of protons in the nucleus of an atom
atomic mass
the total number of protons and neutrons in the nucleus of an atom
The atomic number for Oxygen is 8, so
there are 8 protons in the atom
Rutherford's gold foil experiment provided evidence that...
there is a dense positively charged nucleus at the center of an atom.
JJ Thomson
used the cathode ray tube to discover electrons
Which particle is responsible for the chemical properties of an atom?
valence electrons
Chadwick discovered the
neutron
This particle is found in the nucleus and has no charge
neutron
Dalton's four postulates
1. all matter is made of atoms, which are indivisible. 2. all atoms of a given element are identical in mass and properties. 3. compounds are combinations of two or more different types of atoms. 4. a chemical reaction is a rearrangement of atoms.
How much does a electron weigh?
1/1840 of a proton
Niels Bohr
1913- discovered that electrons move around the nucleus in orbits called electron shells.
Which is the correct sequence of the scientists who made major changes in the model of the atom? 1-JJ Thomson 2-Erwin Schrodinger 3-John Dalton 4-Niels Bohr 5-Ernest Rutherford
3, 1, 5, 4, 2
Oil Drop Experiment
A drop of oil was placed in a cylinder with negative and positive plates, the drops were charged using an x-ray. Different waves of xrays let the drops fall at different rates. Determined that the mass of the electron is 9.10 x 10^-28 by Robert Milikan
Electron
A subatomic particle that has a negative charge
proton
A subatomic particle that has a positive charge and that is found in the nucleus of an atom
neutron
A subatomic particle that has no charge and that is found in the nucleus of an atom
What was Rutherford's experiment?
Gold foil experiment
Democritus
Greek philosopher that said all matter is made of tiny particles called "atomos" or atoms
What contribution did John Dalton make to atomic theory?
He discovered that every element consisted of one type of atom.
This is the simplest of all atoms and contains only one proton and one electron
Hydrogen
The word atom comes from a Greek word "atomos" that means
Indivisible
Plum Pudding Model
J.J Thomsons model of an atom, in which he thought electrons were randomly distributed within a positively charged cloud
What scientist is best known for his "Plum Pudding" model of the atom?
J.J. Tomson
What scientist first developed 4 rules for atomic theory, and helped kick start modern chemistry?
John Dalton
Who came up with this model of an atom?
Neils Bohr
What was Millikan's experiment?
Oil drop experiment
An atom's overall charge is ________.
neutral
True or False: The majority of an atom is made up of empty space
True
atomic mass unit (amu)
a unit of mass equal to one-twelfth the mass of a carbon-12 atom
The majority of an atom's mass exists where?
in the nucleus
atomos
indivisible and industructible
why didn't Rutherford's model last long?
it did not explain anything
