Answer:
A balance and a graduated cylinder.
Explanation:
Density is the relationship between mass and volume of a substance, the formula is:
ρ\(=m.v\)
Where m is the substance mass, and v is the volume.
If a student wants to measure the density of seawater, he or she should use a Balance, to measure the mass of the sample. And then use a Graduated cylinder, is a volumetric instrument that allows to contain liquids and then measures the exact volume of the sample.
Once the student obtains the mass and the volume, he/she has to replace the data in the density formula and so obtain the density of seawater.
