A covalent bond is a chemical bond that occurs when two or more atoms share electrons. The sharing of electrons helps complete the outer shell, or valence shell, of both atoms. The sharing of electrons creates a stable balance of attractive and repulsive forces between atoms.

#Id: 1961

#XL - T Zoology

#Id: 1962

#XL - T Zoology

A life table provides data on the number of individuals alive in different age classes and the age-specific survival or mortality rates in these age classes.

#Id: 1963

#XL - T Zoology

#Id: 1964

#XL - T Zoology

A static life table accomplishes the same goal, but instead of following a cohort of individuals from life to death, data is gathered on the age structure of a given population at one point in time.

#Id: 1966

#XL - T Zoology

#Id: 1967

#XL - T Zoology