atomic theory
the proton has a mass of ______
1 amu
name dalton's 4 postulates
1. all elements are composed of atoms 2. atoms of the same element are identical, the atoms of one element are different from another 3. atoms of different elements mix in whole number ratios 4. in chemical reactions, atoms of one element never change to another
mass of an electron is
1/1840 amu
if an atom has 10 electrons, how many protons does it have
10
an atom of argon has 18 protons and 22 neutrons. how many electrons does it have
18
what year was the plum pudding model made
1897
mass of a neutron is
1amu
a phosphorus atom has 15 protons and 16 neutrons. what is the mass number
31
how many electrons are in an atom with an atomic number of 50
50
an element has a mass number 12 and atomic number 6... how many neutrons does it have
6
an element with a mass number of 11 and an atomic number of 5 has how many neutrons
6
oxygen has 8 protons. what is oxygen's atomic number?
8
Who made the Atomic Model and in what year
Bohr in 1911
Who made the Quantum Mechanical Model and in what year?
Erwin Schrodinger in 1926
who discovered the proton
Eugene Goldstein
who discovered the electron
JJ Thomson
the electron was discovered in 1897 by______
JJ thomson
who discovered the neutron
James Chadwick
who stipulated that electrons orbit the nucleus at fixed energies and distances?
Niels Bohr
What was the plum pudding model?
a positive sphere with electrons
atoms with a negative charge
anion
what type of ion contains an element name with "ide" on the end
anion
which philosopher stated that matter was made of four elements:earth wind water and fire
aristotle
soon after bohr's planetary model took center stage, experiments showed that electrons behaved____
as both particles and waves
the _____________of an element is the weighted average of the masses of the different isotopes of that element
atomic mass
what is an isotope
atoms with the same number of protons but different number of neutrons
atom with a positive charge
cation
Dalton proposed that atoms_____
could neither be created nor destroyed
who first proposed that everything in the world was made up of tiny particles
democritus
what conclusion was made from rutherford
dense and empty nucleus
which particles are not included in the mass number
electrons
what conclusion was made from bohr's model
electrons stay in orbits
dalton concluded that the various compounds were combinations of atoms of different_____
elements
which scientist became known as "the father of the nuclear age"
ernest rutherford
whose experiment involved shooting positively charged alpha particles at a sheet of gold foil
ernest rutherford
democritus called the tiniest particles of matter "atomos", which is Greek for____
indivisible
an atom or group of atoms that has a positive or negative charge
ion
whose model showed atoms as uniformly packed spheres of positive matter filled with negatively charged electrons
jj thomson
in 1808, who was the Quaker teacher that challenged Aristotelian theory?
john dalton
who conducted the billiard ball model and in what year
john dalton and democritis in 1800
as electrons circling an atom shift between energy levels, they absorb or release energy in the form of____
light of a specific wavelength
the _________ is always equal to the number of protons and the number of neutrons that the atom has
mass number
an atom that gains an electron will have a ________ charge
negative
who drew on the work of planck and einstein to develop the planetary model of the atom
niels bohr
the mass of an atom is located in the _______ and the volume of an atom is made of the_____
nucleus, electron cloud
what is the atomic number
number of protons
what model did thomson create
plum pudding
the nucleus is _______ charged whereas the electron cloud is ______ charged
positively, negatively
what subatomic particles would you find in the nucleus of an atom
protons and neutrons
which subatomic particles contribute the most to the mass of an atom
protons and neutrons
who concluded that atoms consisted largely of empty space with most of the mass concentrated in the center?
rutherford
who concluded the planetary model and in what year
rutherford in 1909
JJ Thompson won a nobel prize in 1906 for his discovery of_____
the electron
what conclusion was made from quantum model
the electron cloud is fuzzy; electrons have dual wave particle characteristics
what did thomson's model conclude
the existence of the electron and their negativity
most of the mass of an atom is contained in _____
the nucleus
rutherford referred to the center of the atom, where the mass was concentrated, as ________
the nucleus
what is the mass number
the number of protons and neutrons
what is true about a neutral atom
the number of protons equal the number of electrons
the current model of the atom, where electrons exist within a range of possible locations, is called______
the quantum model
Dalton showed that common substances always broke down into____
the same elements in the same proportions
Who showed it was impossible to determine both the exact position and speed of electrons as they moved around an atom?
werner heisenberg
