How many fluorine atoms bond with calcium to form calcium fluoride?

The number to the right of an element's symbol (ex. c-12) identifies the of an isotope.

Maya wrote if you step to describe how carbon circulates between the atmosphere and living organisms

A2-kg bowling ball is 1 meter off the ground on a post when it falls. just before it reaches the ground,its traveling 4.4 m/s. assuming that there is no air resistant, which statement is true a. the initial potential energy is less then the final kinetic energy b. the mechanical energy is not conserved c. the mechanical energy is conserved d. the initial potential energy is greater than the final kinetic energy