Chapter 4 Atoms And Periodic Table Flashcards
Nucleus
A small, dense substance that is located in the center of each atom
Positive electric charge
Proton
A subatomic particle that has a positive charge
Neutron
A subatomic particle that has no charge
Electron
Subatomic particles with negative charges
Orbital
A region in an atom where there is high probability of finding electrons
Valence electron
Electrons found in the outermost shell of an atom and determine the atoms chemical properties
Periodic Law
States that when elements are arranged in order of number of protons, the similarities in their protons will occur in a regular pattern
Period
The horizontal rows in the periodic table
Group
The vertical column of elements in the periodic table
Ion
An atom or group of atoms that has lost or gained one electron and has a negative or positive charge
Atomic Number
Number of an atom that equals the number of protons in the nucleus
Mass Number
Number of an atom that equals the number of protons plus the number of neutrons in the nucleus
Isotope
An atom that has has the same number of protons as other atoms of the same element do but has a different number of neutrons
Atomic Mass Unit (amu)
Unit of mass that is equal to one twelfth of the mass of a carbon- 12 atom
Average Atomic Mass
A weighted average of the masses of all naturally-occurring isotopes of an element
Metal
Elements that are shiny and conduct heat and electricity well
Nonmetal
All except Hydrogen of which are found on the right side of the periodic table, including solids, liquids, or gasses at room temperature
Semiconductor
Element that can conduct electricity under certain conditions
Alkali Metal
Very reactive elements on the periodic table
Found in group 1
Alkaline-earth Metal
Elements that are somewhat less reactive than alkali metals including calcium
Found in group 2
Transition Metal
Elects such as gold, iron and mercury which occupy groups 3-12 of the periodic table
Halogen
Elements such as chlorine which are located in group 17 of the periodic table
Noble Gas
Unreactive elements such as neon which make up group 18 of the periodic table
Mole
The number of particles that is in the same as the number of atoms of carbon in 12g of carbon-12
Avogadro’s Factor
The number of particles per mol of a substance:
6.022 x 10^23
Molar Mass
The mass in grams of 1 mol of a substance
Conversion Factor
A ratio that is derived from the equality of two different units
