Why does the heaviness of an object not relate to the density

Scientists define density as the mass of a substance per unit volume. The word “per”

signals that thinking about density requires thinking about a relationship. It is the relation

between the mass (or weight) of one unit of a material and the volume of that one unit.

Density cannot be directly perceived or measured. It must be inferred from the

relationship of the mass and volume. However, it can be determined by calculation

which is how many schools teach it. To calculate density, you first measure the weight

and volume of an object precisely, then you divide the mass by the volume (i.e. d=m/v,

density equals mass divided by volume). So for example, the density of water is 1 gram

per cubic centimeter because a volume of 1 cubic centimeter of water has a mass of 1

gram. A substance which has a mass of greater than one gram per cubic centimeter

has a density greater than 1.0 gram per cubic centimeter; a substance which has a

mass of less than one gram per cubic centimeter has a density of less than 1.0 gram

per cubic centimeter.

Explanation:

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."

the dna molecules have a negative charge because of the phosphate groups in their sugar-phosphate backbone, so they start moving through the matrix of the gel towards the positive pole. power is turned on and dna fragments migrate through gel (towards the positive electrode).

explanation: