Denominators and numerators mean:

1, denominator:

The number or algebraic expression written below the fractional line in a fraction is called the denominator. Fractions with known denominator are called algebraic expressions, and fractions with unknown denominator are called fractions. Denominator cannot be zero.

2. Molecules:

Molecules are a whole composed of atoms in a certain bonding order and spatial arrangement, which is called molecular structure. Due to the interaction between atoms in the molecule, the physical and chemical properties of the molecule depend not only on the types and quantities of the constituent atoms, but also on the structure of the molecule.

It is best to determine the molecular structure at a temperature close to absolute zero, because the molecular curl increases with the increase of temperature. The shape of molecules can be calculated by quantum mechanics and semi-experimental molecular simulation, and the structure of solid molecules can also be determined by X-ray crystallography.

Larger molecules usually exist in multiple stable conformations, and the energy barrier between these conformations is higher on the potential energy surface. Molecular structure is related to the position of atoms in space and the type of chemical bonds, including bond length, bond angle and dihedral angle between three adjacent bonds.

Extended data:

1. The score indicates that one number is the score of another number, or the ratio of one event to all events. Divide the unit "1" into several parts on average, and the number representing such a part or parts is called a fraction. The numerator is above and the denominator is below.

2. Fractions can be expressed by division formula: for example, half equals 1 divided by 2. Where 1 numerator equals dividend, fractional line equals divisor, denominator equals divisor, and 0.5 fraction equals quotient.

3. Fractions are either finite decimals or infinite cyclic decimals, and infinite acyclic decimals like π cannot be replaced by fractions. Every score has an infinite number of equal scores.

4. Fraction can be expressed by numerator reading as denominator and denominator as radix. Even in the case of a solid fraction, the term "end" is used, where the numbers are located to the left and right of the diagonal mark. Fractions that are not the big denominator of the power of 10 are usually expressed in this way, and the denominator with a fraction of 10 is usually read in normal order.