Chapter 4 Flashcards
Nucleus
The nucleus of an atom is made of protons and neutrons. The nucleus itself has a positive charge.
Proton
Protons have a positive electric charge.
Neutrons
Neutrons have no charge.
Electrons
Electrons have a negative electric charge.
Orbital
An orbital is a region in an atom where there is a high probability of finding electrons.
Valence electrons
Valence electrons are found in the outermost shell of an atom and determine the atom’s chemical properties.
Periodic law
The periodic law states that when elements are arranged this way, similarities in their properties will occur in a regular pattern.
Period
A period is a horizontal row in the periodic table.
Group
A group is a vertical column of elements in the periodic table.
Ion
An ion is an atom or group of atoms that has lost or gained one electrons and has a negative or positive charge.
Atomic number
The atomic number of an atom equals the number of protons in the nucleus.
Mass number
The mass number of an atom equals the number of protons plus the number of neutrons in the nucleus.
Isotope
An isotope is an atom that has the same number of protons as other atoms of the same element do,but that has a different number of neutrons.
Atomic mass unit
An atomic mass unit is equal to one twelfth of the mass of an atom.
Average atomic mass
The average atomic mass for an element is a weighted average of the masses of all naturally-occurring isotopes of an element.
Metal
Metals are shiny and conduct heat and electricity well.
Nonmetal
A nonmetal is an element that are found on the right side of the periodic table, and may be solids, liquids, or gases at room temperature.
Semiconductor
A semiconductor is an element that can conduct electricity under certain conditions. They are grouped between metals and nonmetals.
Alkali metals
Alkali metals are found in Group 1, and are very reactive.
Alkaline earth metals
Alkaline earth metals are found in Group 2, and are less reactive than the alkali metals.
Transition metals
Transition metals are are found in Group 3-12 of the periodic table.
Halogen
Halogens are located in Group 17 of the periodic table.
Noble gases
Nobel gases are different from most elements that are gases, because they exist as single atoms instead of as molecules.
Mole
A mole is a collection of a very large number of particles.
Avogadro’s constant
Avogadro’s constant is written as 6.022 x 10^23
Molar mass
The mass in grams of 1 mole of a substance is called its molar mass.
Conversion factors
Conversion factors are when you can convert moles to grams and vice versa, since the amount of a substance and its mass are related.
