Democritus coined this word for a tiny piece of matter that cannot be divided.
Atom
Electrons are included in the atomic mass. True/False
False
The number of protons in an atom of a certain element.
Atomic number
A subatomic particle with a neutral charge.
A neutron
The element that has 0 electrons, 1 proton, and 2 neutrons.
Hydrogen
____________'s model of the atom was represented by a solid sphere with a predictable mass for each element.
Dalton
In a neutral atom, the number of electrons equals the number of ____________.
Protons
The sum of protons and neutrons in the nucleus of an atom.
Mass number
The same element but with a different numbers of neutrons.
Isotope
If an atom has 10 protons, 10 neutrons, and 10 electrons, the atomic mass equals _____________.
20
The scientist who proposed the "plum pudding model".
J.J. Thomson
The path in which an electron moves according to the Bohr model of the atom.
Orbital
The elements in the periodic table are arranged by the ____________________.
Atomic number
When an atom gains or loses energy, some of the electrons may change _________________.
Energy levels
The number of neutrons in C-14.
8
While using gold foil in his experiment, Rutherford discovered this subatomic particle.
Proton (positive charge)
Who discovered the presence of a negative charge in the structure of the atom.
J.J. Thomson
Both __________ and _________ have the same mass of 1 Atomic Mass Unit (AMU).
Protons and neutrons
Light is emitted as electrons move from ________ to _________ energy levels.
Dalton stated that when elements combine in a compound, the ___________ of their masses is always the same.
Ratio
The current atomic model that describes the most likely location of an electron.
Electron Cloud Model
How many electrons does the first orbital/energy level hold in any atom?
2
Number of neutrons
This is what the electrons in the outer most energy level of an atom are called.
Valence electrons
Probability