Atom
Smallest unit of ordinary matter that forms a chemical element.
- Atom500 related topics
Proton
Stable subatomic particle, symbol, H+, or 1H+ with a positive electric charge of +1e elementary charge.
Stable subatomic particle, symbol, H+, or 1H+ with a positive electric charge of +1e elementary charge.
One or more protons are present in the nucleus of every atom.
Picometre
Unit of length in the metric system, equal to 1 m, or one trillionth (1⁄1,000,000,000,000) of a metre, which is the SI base unit of length.
Unit of length in the metric system, equal to 1 m, or one trillionth (1⁄1,000,000,000,000) of a metre, which is the SI base unit of length.
Atoms are between 62 and 520 pm in diameter, and the typical length of a carbon–carbon single bond is 154 pm.
Nuclear fission
Nuclear fission is a reaction in which the nucleus of an atom splits into two or more smaller nuclei.
Atomic number
Charge number of an atomic nucleus.
Charge number of an atomic nucleus.
For ordinary nuclei, this is equal to the proton number (np) or the number of protons found in the nucleus for every atom of that element.
Chemical bond
Compare molecular binding, which often includes chemical bonding.
Compare molecular binding, which often includes chemical bonding.
A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds.
Electric charge
Physical property of matter that causes it to experience a force when placed in an electromagnetic field.
Physical property of matter that causes it to experience a force when placed in an electromagnetic field.
In ordinary matter, negative charge is carried by electrons, and positive charge is carried by the protons in the nuclei of atoms.
Molecule
A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion.
Crystal
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.
Chemical compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) composed of atoms from more than one element held together by chemical bonds.
Hydrogen
Chemical element with the symbol H and atomic number 1.
Chemical element with the symbol H and atomic number 1.
For the most common isotope of hydrogen (symbol 1H) each atom has one proton, one electron, and no neutrons.