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 about 0.21 mol O2.


Health / First Aid / Moleskin: Soft material that reduces friction and protects skin. 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

Polar Molecule

Science / Chemistry / Polar Molecule: An asymmetric molecule containing polar bonds. H2O, NH3, and hcl are examples of polar molecules. Non-examples are CO2, ccl4, and bcl3 which contain polar bonds but are nonpolar because they have symm MORE

Polyatomic Molecule

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


Science / Biology / Molecules: Units of two or more atoms held together by chemical bonds. The combination of atoms by chemical bonds with the component atoms in definite porportions, such as water (two H to one O). MORE


Science / Chemistry / Molecule: The smallest particle of an element or compound that retains the chemical properties of the element or compound. A molecule is a collection of chemically bound atoms with characteristic composition an MORE