Which of these is a biotic factor in an ecosystem?
a. rain
b. wind
c. bacteria
d. rock

How do dying stars contribute to the formation of planets

Why can water dissolve many ionic compounds

Dumbledore decides to gives a surprise demonstration. he starts with a hydrate of na2co3 which has a mass of 4.31 g before heating. after he heats it he finds the mass of the anhydrous compound is found to be 3.22 g. he asks everyone in class to determine the integer x in the hydrate: na2co3·xh2o; you should do this also. round your answer to the nearest integ