Atoms and Elements

These flashcards cover essential terms and definitions related to atoms and elements as per the chemistry lecture notes.

Element

A pure substance that cannot be broken down into simpler substances.

Chemical Symbol

A one- or two-letter abbreviation for an element's name.

Groups

Vertical columns on the periodic table that contain elements with similar properties.

Periods

Horizontal rows on the periodic table.

Valence Electrons

Electrons located in the outermost energy level of an atom.

Metalloids

Elements that exhibit properties of both metals and nonmetals.

Atomic Number

The number of protons in the nucleus of an atom, unique to each element.

Mass Number

The total number of protons and neutrons in an atom's nucleus.

Isotopes

Atoms of the same element that have different mass numbers.

Ionization Energy

The energy required to remove an outermost electron from an atom.