Atomic radius generally decreases across a period (from left to right) due to increasing nuclear charge pulling electrons closer to the nucleus. It increases down a group due to additional electron shells.
Atomic Radius: 152 pm
Larger atomic radius due to fewer protons and only 2 electron shells.
Atomic Radius: 72 pm
Smaller radius despite same electron shells as Li because 9 protons pull electrons more tightly.
Atomic Radius: 227 pm
Larger radius than Li due to additional electron shell, despite more protons.
Ionization energy generally increases across a period and decreases down a group. Higher ionization energy means electrons are harder to remove from the atom.
Ionization Energy: 496 kJ/mol
Lower ionization energy due to the outer electron being farther from nucleus.
Ionization Energy: 2081 kJ/mol
High ionization energy due to stable filled shell configuration.
Ionization Energy: 738 kJ/mol
Higher than Na but lower than Ne, showing the periodic trend.
Electronegativity increases across a period and decreases down a group. It measures an atom's ability to attract electrons in a chemical bond.
Electronegativity: 2.55
Moderate electronegativity makes carbon versatile in forming bonds.
Electronegativity: 3.98
Highest electronegativity of all elements, creates strong polar bonds.
Electronegativity: 3.16
Lower than F but still high, demonstrating the decrease down a group.
Reactivity varies across the periodic table with alkali metals and halogens being highly reactive. Noble gases are least reactive due to their stable electron configurations.
Very reactive metal that reacts violently with water, easily losing its outer electron.
Reactive halogen that readily gains electrons to achieve stable configuration.
Virtually unreactive noble gas with filled outer shell, requiring extreme conditions to form compounds.