click below
click below
Normal Size Small Size show me how
Ch 4 Atoms & Element
Vocabulary words
Question | Answer |
---|---|
alkali metal | an element in group 1 of the periodic table |
alkaline earth metals | the elements in Group 2A of the periodic table |
anions | negatively charged ions |
atom | Basic unit of matter |
atomic mass | the weighted average of the masses of the isotopes of an element |
atomic mass unit | one twelfth the mass of a carbon-12 atom |
atomic number (Z) | the number of protons in the nucleus of an atom |
cation | A positively charged ion |
charge | A measure of the extra positive or negative particles that an object has. A fundamental property of protons and electrons. |
chemical symbol | A one or two letter representation of an element |
electron | A subatomic particle that has a negative charge |
family (of elements) | Elements that are in the same COLUMN (also called group). Elements in a family have similar physical and chemical properties |
group (of elements) | elements that exhibit similar physical and chemical properties; arranged in columns (also called family) on the periodic table |
halogens | Contains nonmetals |
ion | An atom or group of atoms that has a positive or negative charge. |
isotope | An atom with the same number of protons and a different number of neutrons from other atoms of the same element. |
main-group elements | groups 1A-8A; these groups have properties that tend to be predictable based on their position in the periodic table. |
mass number | the sum of the number of neutrons and protons in an atomic nucleus |
metalloids | elements with properties that fall between those of metals and nonmetals |
metals | Elements that tend to lose electrons in chemical reactions. They are found at the left side and in the center of the periodic table. |
neutron | A subatomic particle that has no charge and nearly the same mass as a proton |
noble gases | the elements in Group 8A of the periodic table and are chemically unreactive. |
nonmetals | Elements that tend to gain electrons in chemical reactions. They are found at the upper right side of the periodic table. |
nuclear radiation | The energetic particles emitted from the nucleus of an atom when it is undergoing a nuclear process. |
nuclear theory of the atom | A theory stating that most of the atom's mass and all of its positive charge are contained in a small |
nucleus | The small core containing most of the atom's mass and all of its positive charge. The nucleus is made up of protons and neutrons. |
percent natural abundance | the percentage amount of each isotope of an element in a naturally occurring sample of the element |
periodic law | A law that states that when the elements are arranged in order of increasing relative mass |
periodic table | A table that shows the elements |
proton | A positively charged nuclear particle. A proton's mass is approximately 1 amu. |
radioactive | describes a substance that emits tiny |
semiconductor | A compound or element exhibiting intermediate electrical conductivity that can be changed and controlled. |
transition elements/metals | The elements in the middle of the periodic table whose properties tend to be less predictable based simply on their position in the periodic table. Transition metals lose electrons in their chemical reactions |