What effect has impurities on the melting and boiling points of pure substances? illustrate your answer with an example pls need it by tonight ​

The presence of an impurity in a substance lowers the melting point, and raises the boiling point of the substance. For example, Impurities present in the water decrease the freezing temperature of the water, and in the same way, impurities increase the boiling point of the water.

the child will have heterozygous dominant chromosomes as characters of his father are dominant over the characters of his mother.

the child is heterozygous

it is the most commonly accepted one