Science / Periodic Table of Elements Glossary

Hassium (Hs): Atomic number: 108, Atomic mass: 264.8 g.mol -1, Electronegativity: unknown, Density: unknown, Melting point: unknown, Boiling point: unknown, Vanderwaals radius: unknown, Ionic radius: unkn . . . View Full Definition

Helium (He): Atomic number: 2, Atomic mass: 4.00260 g.mol -1, Electronegativity: unknown, Density: 0.178*10 -3 g.cm -3 at 20 °C, Melting point: - 272.2 (26 atm) °C, Boiling point: - 268.9 °C, Vanderwaals . . . View Full Definition

Holmium (Ho): Atomic number: 67, Atomic mass: 164.9 g.mol -1, Electronegativity: 1.2, Density: 8.8 g.cm-3 at 20°C, Melting point: 1474 °C, Boiling point: 2695 °C, Vanderwaals radius: unknown, Ionic radius . . . View Full Definition

Hydrogen (H): Atomic number: 1, Atomic mass: 1.007825 g.mol -1, Electronegativity: 2.1, Density: 0.0899*10 -3 g.cm -3 at 20 °C, Melting point: - 259.2 °C, Boiling point: - 252.8 °C, Vanderwaals radius: 0. . . . View Full Definition

Indium (In): Atomic number: 49, Atomic mass: 114.82 g.mol -1, Electronegativity: 2, Density: 7.31 g.cm-3 at 20°C, Melting point: 156 °C, Boiling point: 2000 °C, Vanderwaals radius: 0.162 nm, Ionic radius . . . View Full Definition

Iodine (I): Atomic number: 53, Atomic mass: 126.9045 g.mol -1, Electronegativity: 2.5, Density: 4.93 g.cm-3 at 20°C, Melting point: 114 °C, Boiling point: 184 °C, Vanderwaals radius: 0.177 nm, Ionic rad . . . View Full Definition

Ionic Radius: The radii of anions and cations in crystalline ionic compounds, as determined by consistently partitioning the center-to-center distance of ions in those compounds.

Ionization Energy: The energy needed to remove an electron from a gaseous atom or ion.

Ionization Energy (IE): The energy required to remove the outermost electron from an atom or a positive ion in its ground level. The table lists only the first IE in eV units. To convert to kJ/mol multiply by 96.48 . . . View Full Definition

Iridium (Ir): Atomic number: 77, Atomic mass: 192.2 g.mol -1, Electronegativity: 2.2, Density: 22.4 g.cm-3 at 20°C, Melting point: 2450 °C, Boiling point: 4527 °C, Vanderwaals radius: 0.126 nm, Ionic radi . . . View Full Definition

Iron (Fe): Atomic number: 26, Atomic mass: 55.85 g.mol -1, Electronegativity: 1.8, Density: 7.8 g.cm-3 at 20°C, Melting point: 1536 °C, Boiling point: 2861 °C, Vanderwaalsradius: 0.126 nm, Ionic radius . . . View Full Definition

Isotope: Atoms of the same element with the same atomic number, but different number of neutrons. Isotope of an element is defined by the sum of the number of protons and neutrons in its nucleus. Ele . . . View Full Definition

Krypton (Kr): Atomic number: 36, Atomic mass: 83.80 g.mol -1, Density: 3.73 10-3 g.cm-3 at 20°C, Melting point: - 157 °C, Boiling point: - 153° C, Vanderwaals radius: 0.197 nm, Isotopes: 15, Electronic sh . . . View Full Definition

Lanthanide: Elements 57-70 are called lanthanides. Electrons added during the Aufbau construction of lanthanide atoms go into the 4f subshell.

Lanthanide Contraction: An effect that causes sixth period elements with filled 4f subshells to be smaller than otherwise expected. The intervention of the lanthanides increases the effective nuclear charge, which . . . View Full Definition

Lanthanum (La): Atomic number: 57, Atomic mass: 138.91 g.mol -1, Electronegativity: 1.1, Density: 6.18 g.cm-3 at 20°C, Melting point: 826 °C, Boiling point: 0.186 nm, Vanderwaals radius: 0.104 nm (+3), Isot . . . View Full Definition

Lawrencium (Lr): Atomic number: 103, Atomic mass: (262) g.mol -1, Electronegativity: unknown, Density: unknown, Melting point: unknown, Boiling point: unknown, Vanderwaals radius: unknown, Ionic radius: unkn . . . View Full Definition

Lead (Pb): Atomic number: 82, Atomic mass: 207.2 g.mol -1, Electronegativity: 1.8, Density: 11.34 g.cm-3 at 20°C, Melting point: 327 °C, Boiling point: 1755 °C, Vanderwaals radius: 0.154 nm, Ionic radi . . . View Full Definition

Page: 1 2 3 4 5 6 7 8 9