Atoms and Elements
The basic unit of matter.
Atom
Atomic number (number of protons)
This Russian chemist created the first periodic table based on observable properties.
Dmitri Mendeleev
Radiation
When a parent nuclide divides into more stable daughter nuclides, often releasing excess neutrons.
Nuclear fission
Elements are categorized into three main groups. Metals, nonmetals, and ____.
Metalloids
One or more atoms of the same element that have different numbers of neutrons.
Isotopes
One-half the distance between nuclei of identical atoms that are bonded together.
Atomic radius
All elements heavier than this are radioactive.
Lead
This particle is released during alpha decay as a high energy helium nucleus.
Alpha particle
While many elements undergo chemical changes to fill their valence electrons, this group of elements does not.
Noble gases
The measurement of both neutrons and protons.
Mass number
Oppositely charged particles are attracted through this force.
Electrostatic force
This type of decay releases a charged particle when a neutron or proton are converted into the other.
Beta Decay
The Gold Foil experiment proved the existence of what within the atom?
The nucleus
1/12th the mass of an atom of Carbon-12. The unit of mass for atoms.
Unified mass units (u)
Shielding Effect
This force holds together the nucleus of atoms.
Strong nuclear force
The energy wave released through Gamma decay
Photon
Reactivity
The tendency of repeating elemental properties on the periodic table.
Periodicity
Electronegativity
The difference of mass between an atom and its subatomic particles.
Mass defect
A positively charged particle with the same mass as an electron.
Positron