1. do you think the density of the ice affected the melting rate of the ice, or do you think adding the objects affected the melting rates? be sure to include data to support your answer.

The density of an object refers to an extensive property, which signifies that it does not rely upon the concentration of the substance. Each and every substance in this world exhibits its characteristic density. Therefore, it would not influence the rate of melting as it does not fluctuate. However, adding the objects could accelerate the procedure as each object exhibits energy in the form of heat, which could provoke the mediating force for the melting process.  

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).