Atomic Structure Vocab Test

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Dalton’s Atomic Theory
~Matter is composed of extremely small particles called atoms.
~Atoms are indivisible and indestructible.
~Atoms of a given element are identical in size, mass, and chemical properties.
~Atoms of a specific element are different from those of another element.
~Different atoms combine in simple whole-number ratios to form compounds.
~In a chemical reaction, atoms are separated, combined or rearranged.
smallest particle of an element that retains the properties of the element
cathode ray
a beam of electrons emitted by the cathode of an electrical discharge tube
The negatively charged particles found in all atoms; are involved in the formation of chemical bonds.
tiny dense region in the center of the atom; contains almost all the mass and holds protons and neutrons; positively charged
subatomic particle carrying a charge equal to but opposite that of an electron (1+) (p)
subatomic particle that has a mass nearly equal to that of a proton, but carries no electric charge (0)(n)
atomic number
number of protons in an atom
atoms with the same number of protons but different number of neutrons
mass number
the sum of the atomic number and neutrons in the nucleus
atomic mass unit (amu)
1/12 the mass of a carbon-12 atom
averege atomic mass
weighted average mass of the isotopes of that element
cathode ray tube
Piece of equipment used by Thomson to discover the electron.
alpha particles
positively charged particles containing two protons and two neutrons, is identical to the nucleus of a helium atom and about 4 times the mass of a hydrogen atom
hyphen notation
name of element – mass # (ex. copper-65)
nuclear forces
the short-ranged proton-neutron, proton-proton, and neutron-neutron forces that hold particles together
nuclear symbol
mass#/atomic# (ex. 65/29 Cu)
refers to any isotope of any element
Plum Pudding Model
model created by JJ Thompson where electrons were stuck into a lump of positive charge
subatomic particles
Particles that are smaller than the atom (protons, neutrons, and electrons)
Categories: Atomic Physics