physical science chapter 4
If 2 grams of element X combine with 4 grams of element Y to form compound XY, how many grams of element Y would combine with 14 grams of X to form the same compound?
28 grams
which statement about subatomic particles is true
An electron has far less mass than either a proton or neutron
according to _______ all matter was made up of four elements - earth air fire water
Aristotle
Who provided evidence for the existence of a nucleus in an atom?
Ernest Rutherford
which of the following provides the best analogy for an electron in an atomic orbital
a bee trying to escape from a closed jar
which of the following most accurately represents John Dolton's model of the atom
a tiny, solid sphere with predictable mass for a given element
in Rutherford's gold foil experiment, some of the __________ aimed at gold atoms bounced back suggesting that a solid mass was at the center of the atom
alpha particle
which statement about electrons and atomic orbitals is not true
an electron has the same amount of energy in all orbitals
the greek philosopher Democritus coined what word for a tiny for a tiny piece of matter that cannot be divided
atom
the number of protons in one atom of an element is that element's
atomic number
to find the numbers of neutrons in an atom of an atom, you would subtract
atomic number from mass number
Unlike Democritus, Aristotle did not believe that matter was composed of tiny, indivisible_______
atoms
which of the following is NOT part of John Dalton's atomic theory
atoms contain subatomic particles
the moving blades of an airplane propeller provided an analogy for the electron _______ model
cloud
Jhon 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 the atom
J.J. Thomson's 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 nucleus
electrons
when an atom gains or loses energy, some of its _________ may move between energy levels
electrons
which statement accurately represents the arrangement of electrons in Bohr's atomic model
electrons travel around the nucleus in fixed energy levels with energies that vary from level to level
John Dalton concluded that all the atoms of a single _____ have the same mass.
element
at atom in which an electron has moved to a higher energy level is in a _______state
exited
when all the electrons in an atom are in orbitals with the lowest possible energy, the atom is in its ______ state
ground
How was Bohr's atomic model similar to Rutherford's model?
it described a nucleus surrounded by a large volume of space
which statement best describes Rutherford's model of the atom
it is like a huge stadium with 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 number
the glowing neon light is caused by electrons emitting energy as they
move from higher to lower energy levels
the subatomic particle that J.J. Thomson discovered has a ________ charge
negative
the difference between a sample of heavy water and regular water is that hydrogen atom in the heavy water has an extra _______
neutron
Protons and______are found in the nucleus of an atom.
neutrons
the nuclei of isotopes contain different numbers of _______
neutrons
the diagram in figure 4-1 shows the results of Rutherford's gold foil experiment. what caused some of the alpha particles to bounce straight back from the gold foil
nuclei in the gold atoms
in Rutherford's gold foil experiment, shown in figure 4-1, alpha particles that bounce straight back from the foil have struck ___________ in the gold atoms
nucleus
If element Q has 11 protons, its atomic ____________________ is 11.
number
the region in which an electron is most likely to be found is called an _______
orbital
What do scientists use to predict the locations of electrons in atoms?
probability
Neutrons and ____________________ have almost the same mass.
protons
which statement about subatomic particles is NOT true
protons and neutrons have the same charge
Democritus thought that matter was made of tiny particles
that could not be divided
what is the difference between an atom in the ground state and the exited state
the atom in the exited state has more energy and is less stable then an atom in the ground state
What can you assume has happened if an electron moves to a higher energy level?
the electron has gained energy
what does the electron cloud model describe
the most likely locations of electrons in atoms
which of the following is unique for any given element
the number of protons
Suppose an atom has a mass number of 23. Which statement is true beyond any doubt?
the number of protons in the nucleus does not equal the number of neutrons
according to Jhon Dalton's observations, when elements combine in a compound
the ratio of their masses is always the same
Rutherford's Gold Foil Experiment provided evidence for which of the following statements
there is a dense, positively charged mass in the center of the atom
which statement is true about oxygen-17 and oxygen-18
they are isotopes of oxygen