Question

A solid will float in a liquid if it is less dense than the liquid, and sink if it is more dense than the liquid. If the density of seawater is 1.025 g/mL, which types of plastics would definitely float in seawater? JUSTIFY your answer.

Answer 1

Step-by-step explanation:

Plastics with a density less than or equal to 1.025 g/mL will float in seawater, while plastics with a density greater than 1.025 g/mL will sink.

Here are some examples of plastic densities:

Polyethylene terephthalate (PET) has a density of approximately 1.38 g/mL, so it will sink in seawater.

Polypropylene (PP) has a density of approximately 0.9 g/mL, so it will float in seawater.

High-density polyethylene (HDPE) has a density of approximately 0.95 g/mL, so it will float in seawater.

Polystyrene (PS) has a density of approximately 1.05 g/mL, so it will sink in seawater.

Based on the above examples, we can see that plastics such as polypropylene and high-density polyethylene will definitely float in seawater, while others such as polyethylene terephthalate and polystyrene will definitely sink. Other types of plastics with densities close to 1.025 g/mL may float or sink depending on their exact density and the conditions of the water, such as temperature and salinity.