Final answer:
The periodic table is used to identify and explain trends in atomic and ionic radius, electronegativity, and ionization energy by organizing elements based on their atomic number and electron configuration.
Step-by-step explanation:
The periodic table is used to identify and explain trends in atomic and ionic radius, electronegativity, and ionization energy by organizing elements based on their atomic number and electron configuration. This organization allows chemists to observe patterns in atomic size and reactivity across periods and groups. The periodic trends in these properties are influenced by factors such as the number of protons in the nucleus, number of electron shells, and the shielding effect. For example, atomic radius generally decreases across a period and increases down a group, while ionization energy and electronegativity increase across a period and decrease down a group.