Which of these is always equal to the element's atomic number?
Number of protons
Number of electrons
Number of nuclei
Number of neutrons
To find the number of neutrons in an atom, you would subtract
Atomic number from mass number
Mass number from atomic number.
Atomic number from electron number.
Isotope number from atomic number.
Which element has an atomic number of 15, same number of protons?
S
Al
Ne
P
Which sentence states what Rutherford concluded from the gold foil experiment?
At atom's positive charge is concentrated in it's nucleus.
Thomson's model of the atom was correct.
An atoms negative charge is concentrated in it's nucleus.
The atom's positive charge is spread evenly about the atom.
Which of the following is NOT part of Dalton's atomic theory?
A compound contains atoms of more than one element.
Atoms contain subatomic particles.
All elements are composed of atoms.
All atoms of the same element have the same mass.
J. J. Thomson's experiments provided evidence that an atom
has a positive charge.
contains negatively charged particles.
has a negative charge.
is the smallest particle of matter.
Which is true when all of an atoms electrons are in orbitals with the lowest possible energies?
The atom is in its ground state.
The atom is in an excited state.
The electrons are in an unstable configuration.
The electrons are in the most stable configuration.
Which of the following is unique for any given element?
Number of protons
Mass of a neutron
Number of neutrons
Charge on the electrons
What does the electron cloud model describe?
The precise location of electrons in atoms
The mass of the electrons in an atom
The most likely location of electrons in atoms
The number of electrons in atoms
Which statement is true about oxygen-17 and oxygen-18?
They do not have the same number of protons.
They are isotopes of oxygen.
Their atoms have an identical mass.
They have the same mass number.
Which statement about subatomic particles is NOT true?
Protons and neutrons have almost the same mass.
Protons and electrons have opposite charges.
Neutrons have no charge.
Protons and neutrons have the same charge.
The glowing of a neon light is caused by electrons emitting energy as they
collide with other electrons.
move from lower to higher energy levels.
collide with the nucleus.
move from higher to lower energy levels.
Who provided evidence for the existence of a nucleus in an atom?
John Dalton
J. J. Thomson
Ernest Rutherford
Democritus
The number of protons in one atom of an element is that element's
isotope.
balanced charge.
atomic number.
mass number.
How was Bohr's atomic model similar to Rutherford's model?
It describes electron position by using electron cloud model
It describes a nucleus surrounded by a large volume of space
Democritus thought that matter was made of tiny particles
that could be divided.
that were all round and smooth.
that could not be divided.
of earth, air, fire, and water.
Democritus coined this word for a tiny piece of matter that cannot be divided
electron
atom
molecule
element
What can you assume has happened if an electron moves to a higher energy level?
The electron has gained energy.
The atom has become more stable.
The atom has lost an electron.
The electron has lost energy.
Which subatomic particle has a negative charge?
Proton
Alpha particle
Neutron
Electron
What do scientists use to predict the locations of electrons in atoms?
Algebra
Ratios and proportions
Geometry
Probability
Which statement tell's how Bohr's model of the atom differed from Rutherford's model?
Bohr's model focused on the neutrons.
Bohr's model focused on the protons.
Bohr's model focused on the electrons.
Bohr's model focused on the nucleus.
Which statement about particles is TRUE?
Neutrons have no charge and no mass.
An electron has far less mass than a proton or a neutron.
Electrons have no mass.
Protons, neutrons, electrons all have about the same mass.
In Bohr's model of the atom, electrons move
like balls rolling down a hill.
like popcorn in a popcorn popper.
like beach balls on water waves.
like planets orbiting the Sun.