CHEMISTRY

• Elements are arranged by increasing atomic number.
• The periodic table is organised into groups (columns) and periods (rows).
• The periodic table is divided into periods, which represent the number of electron shells an atom has.
• Groups (columns) contain elements with similar properties due to their valence electrons being in the same energy level.
• Metals are found on the left side of the periodic table, while non-metals are located on the right side.
• Groups contain elements with similar properties, while periods have the same number of energy levels.