Glossary -Chemistry Terms
1-Absolute zero – a theoretical condition concerning a system at zero Kelvin where a system does not emit or absorb energy (all atoms are at rest)
2-acid – a compound that, when dissolved in water, gives a pH of less than 7.0 or a compound that donates a hydrogen ion
3-acid dissociation constant – an equilibrium constant for the dissociation of a weak acid
4-acid anhydride – a compound with two acyl groups bound to a single oxygen atom
5-activation energy – the minimum energy that must be input to a chemical system
6-Avogadro’s number – is the number of particles in a mole of a substance ( 6.02×10^23 )
7-Avogadro’s law (sometimes referred to as Avogadro’s hypothesis or Avogadro’s principle) is an experimental gas law relating volume of a gas to the amount of substance of gas present.
Avogadro’s law states that, “equal volumes of all gases, at the same temperature and pressure, have the same number of molecules”.
8-The atomic radius of a chemical element is a measure of the size of its atoms, usually the mean or typical distance from the center of the nucleus to the boundary of the surrounding cloud of electrons.
9-In chemistry and physics, the atomic number of a chemical element (also known as its proton number) is the number of protons found in the nucleus of an atom of that element, and therefore identical to the charge number of the nucleus
10-The unified atomic mass unit (symbol: u) or dalton (symbol: Da) is the standard unit that is used for indicating mass on an atomic or molecular scale (atomic mass). One unified atomic mass unit is approximately the mass of one nucleon (either a single proton or neutron) and is numerically equivalent to 1 g/mol.
11-atom – a chemical element in its smallest form, and is made up of neutrons and protons within the nucleus and electrons circling the nucleus
12-anode – the positive side of a dry cell battery or a cell
13-anion – negatively charge ions
14-allotropy – elements that can have different structures (and therefore different forms), such as Carbon (diamonds, graphite, and fullerene)
15-The alkaline earth metals are six chemical elements in column (group) 2 of the Periodic table. They are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).
16-The alkali metals are a group (column) in the periodic table consisting of the chemical elements lithium (Li), sodium (Na), potassium (K),[note 1] rubidium (Rb), caesium (Cs),[note 2] and francium (Fr). This group lies in the s-block of the periodic table of elements .
17-aeration – the mixing of air into a liquid or solid
18-actinides – the fifteen chemical elements that are between actinium (89) and lawrencium (103)