There are two naturally occurring isotopes of boron. B-10 has a mass of 10.01 amu with an abundance of 19.80 % and the isotope B - 11 has a mass of 11.01 amu with an abundance of 80.20%. What is the atomic mass of boron? (Show work to get full credit)

Which is a characteristic of the electron sea model for metallic bonding? molecular orbitals overlap to produce bands. electrons flow easily between metal nuclei. electrons are in fixed positions in the orbitals. atomic nuclei are arranged in an irregular pattern.