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Chemistry Test 1-2
atom
Question | Answer |
---|---|
believed that particles could be divided until a basic particle that cannot be broken down further is reached | Democritus |
called the particle the atom | Democritus |
atom is from the Greek word that means____ | indivisible |
thought mnatter was continuous; views set back the development of chem. for 2000 years; did not believe in the atom | Aristotle |
mass is neither created or destroyed during ordinary chemical reactions or physical changes | Law of Conservation of Mass |
a chemical compound contains the same element in exactly the same proportions by mass regardless of the size of the sample or the source of the compound | Law of Definite Proportions |
relates to compounds made of the same elements | Law of Multiple Proportions |
the smallest particle of an element that keeps the chemical properties of that element | atom |
2 regions of the atom: | nucleus and electron cloud |
observed that objects can have a positive or negative charge and that like charges repel while unlike charges attract | Ben Franklin |
first to realize that an atom's structure is related to electricity | Michael Faraday |
resulted from investigations into the realtionship between matter and electricity | discovery of atomic structure |
tube containing a gas at low pressure | cathode ray tube |
showed that the cathode rays are made of identical negatively charged particles later called electrons | JJ Thomson |
confirmed that electrons are negative and discovered their mass | Robert Millikan |
mass of an electron | 9.11x10^-28 g |
discovered plum pudding model | JJ Thomson |
discovered planetary model | Rutherford |
discovered Bohr Model | Neils Bohr |
discovered the Quantum Mechanical Model (Schrodinger Model) | Schrodinger |
described the atom as neutral with the same number of negative charges stuck in a ball of positive charges | plum pudding model |
compared an atom to a solar system with electrons moving about the nucleus like planets around the sun | planetary model |
said the electrons with a specific amount of energy moved in a particular orbit; also said that only a certain number of electrons fit in a particular orbit | Bohr Model |
current atomic model; describes the atom as a nucleus surrounded by an electron cloud; electrons moved around the nucleus in regions of space based on the amount of energy the electrons hold; no precise orbits | Schrodinger Model |
discovered the nucleus | Rutherford |
location of the atom's greatest mass | nucleus |
the simplest hydrogen atom has_ proton | 1 |
mass of a proton | 1.673 x 10^-24 g |
mass of a neutron | 1.675 x 10^-24 g |
discovered the proton | Goldstein |
discovered the neutron | Chadwick |
___ provides volume for an atom | electron cloud |
an atom has _ energy levels | 7 |
__ and __ were the first to say electrons move in an atom | Rutherford and Bohr |
the distance from the center of the nucleus to the outer part of the electron cloud | atomic radius |
atoms of the same element that have different masses | isotopes |
H-1 | protium (simplest atom) |
H-2 | deuterium |
H-3 | tritium (radioactive and man made) |
any isotope of any element | nuclide |
the element that all atomic masses are compared to | Carbon-12 |
ratio of the average atomic masses of the naturaly occurring isotopes of an element to 1 amu | atomic weight (atomic mass) |