Chapter 9 and 10: Structure of the Atom and Periodic Table

These flashcards cover essential vocabulary and key concepts related to the structure of the atom and the periodic table from chapters 9 and 10, preparing for an exam on atomic theory and elemental properties.

Atomic Number

The number of protons in the nucleus of an atom.

Mass Number

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

Isotopes

Atoms of the same element that have different numbers of neutrons.

Ions

Atoms or molecules that have gained or lost one or more electrons, resulting in a charge.

Electron Cloud

The region around the nucleus of an atom where electrons are likely to be found.

Periodic Table

A table that organizes all known elements by atomic number and their properties.

Metalloids

Elements that have properties of both metals and nonmetals.

Groups

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

Periods

Horizontal rows on the periodic table that indicate the number of electron shells.

Nucleus

The central part of an atom containing protons and neutrons.

Proton

A positively charged subatomic particle found in the nucleus of an atom.

Neutron

A neutral subatomic particle found in the nucleus of an atom.

Electron

A negatively charged subatomic particle that orbits the nucleus of an atom.

Mendeleev

Created the first version of the periodic table based on atomic mass.

Modern Version of Periodic Table

Organizes elements by increasing atomic number and reflects periodic properties.

Alkali Metals

Group 1 elements that are highly reactive and have one electron in their outer shell.

Noble Gases

Group 18 elements that are inert and have full outer electron shells.