Atom between atoms. By this mechanism, atoms are able to bond into molecules and other types of chemical compounds like ionic and covalent network crystals. By definition, any two atoms with an identical number of "protons" in their nuclei belong to the same chemical element. Atoms with equal numbers of protons but a different number of "neutrons" are different isotopes of the same element. For example, all hydrogen atoms admit exactly one proton, but isotopes exist with no neutrons (hydrogen-1, by far the most common form, also called protium), one neutron (deuterium), two neutrons (tritium) and more than two neutrons. The
Given name a name is not assigned at birth, one may be given at a naming ceremony, with family and friends in attendance. In most jurisdictions, a child's name at birth is a matter of public record, inscribed on a birth certificate, or its equivalent. In western cultures, people normally retain the same given name throughout their lives. However, in some cases these names may be changed by following legal processes or by repute. People may also change their names when immigrating from one country to another with different naming conventions. In certain jurisdictions, a government-appointed registrar of births may refuse to