The decay rate of 7Be depends on the electron density at the nucleus and therefore may vary with the chemical environments of the Be atom. Using a 100% efficiency high-purity germanium detector, the decay constants of Be in Be2C(OH2)4, Be(OH)2 and BeO have been measured at unprecedented high precision (of š0.01%), resulting in T1=2 D 53.69 d, 53.42 d, and 54.23 d, respectively. The observed dif...