atomic structure and the periodic table

• All elements are made up of atoms
• Atoms can be neutral, positive (cation), or negative (anion).
• Ions are atoms that have gained or lost electrons to become electrically charged.
• Atomic number is the number of protons in the nucleus of an atom
• Mass number is the total number of neutrons and protons in the nucleus of an atom
• An ionic bond occurs when one atom loses electrons to another atom
• Isotopes are atoms of the same element with different numbers of neutrons
• The periodic table is a table that lists all the elements in order of increasing atomic number.
• Metals are found on the left side of the periodic table, while non-metals are found on the right side.
• Elements can be classified as metals or non-metals based on their properties such as conductivity, malleability, ductility, luster, reactivity, and density.
• Non-metals are not good conductors of electricity and heat, do not reflect light well, and are brittle at room temperature.
• A metal is any substance that has good electrical conductivity, thermal conductivity, reflectance, lustre, and ductility/malleability.
• Non-metals have poor electrical conductivity, low melting points, and do not form positive ions.