Is a chemical message sent by another individual.

When a comet collides with earth, it adds material to our planet and causes great damage. therefore, a collision like this is a a. destructive force b. constructive force c. geologic process and event d. constructive and destructive force

Suppose you wanted to make 100 grams of water. what is the molar mass of water (h2o)?

The vapor pressure of ethanol is 1.00 × 102 mmhg at 34.90°c. what is its vapor pressure at 61.61°c? (δhvap for ethanol is 39.3 kj/mol.)