Please help, any and all is very much appreciated!

A48 g piece of ice at 0.0 ∘c is added to a sample of water at 7.4 ∘c. all of the ice melts and the temperature of the water decreases to 0.0 ∘c. how many grams of water were in the sample?

What are the primary responsibilities of a chemical engineer involved in "r& d"? develop large scale manufacturing operations discover new products and processes training of new chemists determine products needed by consumers

An electron moved from shell n = 2 to shell n = 1. what most likely happened during the transition? a fraction of a photon was added. a photon of energy was absorbed. a fraction of a photon was removed. a photon of energy was released.