science protons
what most accurately represents john dalton's model of the atom
a tiny solid sphere w/ a predictable mass for a given element
what is true about subatomic particles
an electron has far less mass than either proton or neutron
the region in which an electrons is most likely to be found is called
an orbital
the greek philosopher democritus coined what word for a tiny price of matter that cant be divided
atom
the number of protons in one atom of an element is that elements
atomic number
To find the number of neutrons in an atom, you would subtract
atomic number from mass number
unlike democritus, Aristotle didn't believe that matter was composed of tiny, indivisible
atoms
the moving blades of an airplane propeller provide an analogy for the electron _____
cloud
john dalton observed that elements always combine in the same ratio to form a particular _____
compound
In an atomic model that includes a nucleus, positive charge is
concentrated in the center of an atom
thomsons experiments provided evidence that an atom
contains negatively charged particles
Which subatomic particle has a negative charge?
electron
In Bohr's model of the atom, ______ move in fixed orbits around the sun
electrons
when an atom gains or lose energy some of its ____ may move between energy levels
electrons
an atom in which an electron has moved to a higher energy level is a ____ state
excited
when all the electrons in an atom are in orbitals w/ the lowest possible energy the atomic is in its ____ state
ground
Rutherford model of the atom
it is a huge stadium with a positively charged marble at the center
In Niels Bohr's model of the atom, electrons move
like planets orbiting the sun
the ____ of an isotope is the sum of the number of protons and neutrons in its nucleus
mass #
the subatomic particles that JJ thomson discovered has a ____ charge
negative
protons and ___ are found in the nucleus of an atom
neutrons
the nuclei of isotope contain different numbers of
neutrons
If element Q has 11 protons, its atomic ____________________ is 11.
number
Neutrons and ____________________ have almost the same mass.
protons
what is not true about subatomic particles is NOT true
protons and neutrons have the same charge
what can you assume has happened if an electron moves to a higher energy level
the electron has gained energy
what is unique for any given element
the number of protons
what is true about oxygen-18 and oxygen-19
they are isotopes of oxygen