Describe what each letter and number
means in the chemical formula below.
C. H₂O

Asolution has a ca2+ concentration of 0.049 m and an f- concentration is 0.147 m at equilibrium. the value of ksp for caf2 at 25°c is 4.0 x 10-11. will this solution form a precipitate? yes no

Iknow the answer is a but i don't know why

State one important difference between a physical change and a chemical change?