29Si29Si

29Si29Si is a placeholder for a hypothetical isotope of the chemical element silicon, denoted by the atomic symbols 29Si. Silicon is a metalloid and the second most abundant element in the Earth's crust.

Isotopes of silicon range in mass number from 21Si to 45Si. Of these, 28Si and 29Si are the most stable and most abundant, making up the majority of natural silicon. Other stable isotopes include 30Si, 31Si, and 34Si.

Not to be confused with 29Si, 29Si is a metastable isotope which if existing, would be formed as a byproduct of the reaction between silicon-30 and a silicon atom with one neutron lacking the nucleus is displaced. However, the creation mechanism and potential applications of the metastable 29Si have not yet been empirically studied.