1. The age of an ancient boat may be determined by comparing the radioactive decay of $C614$ from living wood with that of wood taken from the ancient boat.

A sample of 4.30 × 10²³ atoms of carbon is removed for investigation from a block of living wood. In living wood one in 10¹² of the carbon atoms is of the radioactive isotope $C614$, which has a decay constant of 3.84 × 10^–12 s^–1. 

Calculate the half-life of $C614$ in years, giving your answer to an appropriate number of significant figures.