Flashcards: Chemistry Final Semester A 2024

Front

Atom

Back

The smallest unit of an element that maintains the identity of the element

Front

Element

Back

A pure substance that cannot be broken down into anything simpler or more stable

Front

Compound

Back

A pure substance that can be chemically broken down into simple and more stable substances; when atoms of two or more elements are chemically combined

Front

Law of conservation of matter

Back

Matter is never created or destroyed, it only changes forms

Front

Valence electrons

Back

Electrons in the outermost energy level of the electron cloud

Front

Atomic number

Back

Number of protons in an atom of the element; used to identify an element

Front

Mass number

Back

Number of protons and neutrons in the nucleus of an atom

Front

Isotopes

Back

Atoms of the same element with different numbers of neutrons

Front

Average atomic mass

Back

Weighted average of all of the different versions of an element; measured in amu

Front

Radioactive decay

Back

When matter and energy are spontaneously emitted from an unstable nucleus that can no longer hold itself together