Periodic table and trends

The atomic number is the number of protons in the nucleus of an atom, which determines the element's identity.

Protons are positively charged particles, neutrons have no charge, and electrons are negatively charged particles.

Number of neutrons = Atomic mass - Atomic number.

The periodic table is a tabular arrangement of elements organized by increasing atomic number, showing periodic trends.

Periods are the horizontal rows in the periodic table, indicating the number of electron shells in the elements.

Groups are the vertical columns in the periodic table, indicating elements with similar chemical properties.

Atomic mass is the weighted average mass of an element's isotopes, measured in atomic mass units (amu).

Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons.

The position of an element in the periodic table helps predict its chemical behavior and properties.

Metals are elements that are typically shiny, good conductors of heat and electricity, and malleable.