hydrogen

noun 0.660

proton

noun 0.639

heavy hydrogen

noun 0.634

dihydrogen

noun 0.630

tritium

noun 0.626

hydronium

noun 0.618

deuterium

noun 0.606

hydrogen ion

noun 0.604

parahydrogen

noun 0.591

proton number

noun 0.569

deuteride

noun 0.563

tritiated water

noun 0.558

oxyhydrogen

noun 0.555

protomer

noun 0.553

hydrogen iodide

noun 0.550

hydride

noun 0.550

hydrogen halide

noun 0.544

standard hydrogen electrode

noun 0.539

protosun

noun 0.538

deuteron

noun 0.531

protoplasm

noun 0.528

hydrogen electrode

noun 0.528

protoporphyrin

noun 0.528

antihydrogen

noun 0.527

hadron

noun 0.527

propyl

noun 0.526

oxonium

noun 0.524

propanone

noun 0.522

carbon-12

noun 0.522

hydrogen bromide

noun 0.520

hydrogen sulfate

noun 0.519

helium

noun 0.519

positronium

noun 0.517

hydrogen burning

noun 0.517

promethium

noun 0.514

biohydrogen

noun 0.514

hydro

noun 0.514

propane

noun 0.511

protome

noun 0.511

titanium hydride

noun 0.510

hydrogen chloride

noun 0.509

alpha particle

noun 0.509

hydrocarbon

noun 0.508

monoisotopic

noun 0.506

proline

noun 0.505

charmonium

noun 0.504

onium

noun 0.502

hydroperoxyl

noun 0.502

tropylium

noun 0.502

phosphonium

noun 0.501

hydrogen spectrum

noun 0.501

protoplanet

noun 0.500