Give me tips on how to get credit in chemistry urgent.

How did planetesmals form planets? a. they broke apart into smaller chunks. b. they collided and stuck together. c. they cooled and pulled ice together. d. they began to rotate.

Based on the equation and the information in the table, what is the enthalpy of the reaction?

Which formula can be used to calculate the molar mass of ammonia (nh3)? molar mass of n + molar mass of h 3 × molar mass of n + molar mass of h molar mass of n + 3 × molar mass of h 3 × molar mass of n + 3 × molar mass of h