Density is mass per unit of volume. which pair of lab instruments would a student use to measure the density of seawater?

1. a caliper and
2. a flask
3. a stopwatch and a beaker
4. a balance and a graduated cylinder
5. a meter stick and a temperature probe

The answer is option 4. a balance and a graduated cylinder.

Explanation:

The graduated cylinder would be used to measure the volume of sea water while a balance will be used to measure the mass. Both values obtained will be used to determine the density of sea water.

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.