Chapter 4 Flashcards
Neutron
A subatomic particle in an atom that doesn’t have an electric charge at all.
Electron
A subatomic particles of an atom that has a negative charge.
Orbital
Regions of an atom where electrons are most likely to be found.
Valence electrons
An electron in the outermost shell of an atom and this is what determines the atom’s chemical properties and its ability to form bonds.
Periodic law
Elements are listed in a certain order in the periodic table because the periodic law explains that when elements are arranged this way, similarities in their properties will occur in a regular pattern.
Period
Horizontal rows in the periodic table.
Group
Vertical column in the periodic table.
Ion
Atom or group of atoms that have lost or gained electrons and have a negative or positive charge.
Atomic number
Number of protons in the nucleus of an atom.
Mass number
Number of protons and neutrons in the nucleus of an atom.
Isotope
Atom with the same amount of protons as other atoms of the same element, but the atom has a different amount of neutrons.
Atomic mass unit (amu)
Unit of mass that describes an atom’s mass.
Average atomic mass
Average of masses of naturally occurring isotopes of an element.
Metal
Element that can conduct heat and electricity well and the metal is shiny.
Nonmetal
Element that can’t conduct heat and electricity well.
Semiconductor
Element or compound that can conduct electric current better than an insulator, but not as well as a conductor.
Alkali metal
Elements of group 1 of the periodic table that is soft and shiny and reacts violently with water.
Alkaline-earth metal
Elements of group 2 of the periodic table and the metals form compounds that are found in limestone and in the human body.
Transition metal
Elements of group 3-12 of the periodic table. Examples include gold, silver, and platinum.
Halogen
Elements of group 17 on the periodic table. Chlorine is a halogen that protect you from harmful bacteria.
Noble gas
Noble gases are elements that exist as single atoms instead of molecules. They are found in group 18 of the periodic table.
Mole
Unit used to measure the amount of a substance whose number of particles is the same as the number of atoms of carbon in 12g of Carbon-12. It is a collection of a very large number of particles which is about 6.022x10^23/mol
Avogadro ‘s constant
It is the number 6.022x10^23/mol that is exactly 1 mol of a pure substance.
Molar mass
The mass of 1 mol of a substance in grams . An example is 1 mol of carbon -12 atoms has a molar mass of 12.00 grams.
