Atoms and Elements Chapter 4

This set of flashcards contains key vocabulary terms and definitions related to the concepts of atoms, elements, and their properties as discussed in the lecture notes.

Atom

The smallest identifiable unit of an element.

Element

A substance that cannot be broken down into simpler substances.

Isotope

Atoms with the same number of protons but different numbers of neutrons.

Atomic Number (Z)

The number of protons in the nucleus of an atom.

Molecule

A combination of two or more atoms bonded together.

Cation

A positively charged ion that is formed when an atom loses electrons.

Anion

A negatively charged ion that is formed when an atom gains electrons.

Plum Pudding Model

J. J. Thomson's model of the atom where negatively charged electrons are embedded in a positively charged 'soup'.

Nucleus

The small, dense center of an atom that contains protons and neutrons.

Periodic Table

A tabular arrangement of all known elements based on increasing atomic number.

Mass Number (A)

The sum of protons and neutrons in the nucleus of an atom.