Science / Chemistry / Mole: SI unit for amount of substance, defined as the number of atoms in exactly 12 g of carbon-12. One mole of a molecular compound contains Avogadro's number molecules and has a mass equal to the substance's molecular weight, in grams.

Mole Fraction

Science / Chemistry / Mole Fraction: Concentration of a substance in a mixture measured as moles of the substance per mole of mixture. For example, the mole fraction of oxygen in air is about 0.21, which means that 1 mol of air contains MORE

Molecular Biology

Science / Biology / Molecular Biology: Field of biology that studies the molecular level of organization. MORE

Molecular Formula

Science / Chemistry / Molecular Formula: A notation that indicates the type and number of atoms in a molecule. The molecular formula of glucose is C6H12O6, which indicates that a molecule of glucose contains 6 atoms of carbon, 12 atoms of hy MORE

Polyatomic Molecule

Science / Chemistry / Polyatomic Molecule: A polyatomic molecule is an uncharged particle that contains more than two atoms. MORE

Molecular Sieve

Science / Chemistry / Molecular Sieve: A material that contains many small cavities interconnected with pores of precisely uniform size. Zeolites are an example. Molecular sieves adsorb molecules that are small enough to pass through their MORE

Nonpolar Molecule

Science / Chemistry / Nonpolar Molecule: A molecule in which the center of positive charge and the center of negative charge coincide. Examples are ccl4 and CO2; counterexamples are chcl3 and H2O. MORE