Ametal stand specifies a maximum load of 450 lb. will it support an aquarium that weighs 59.5 lb and is filled with 37.9 l of seawater (d = 1.03 g/ml)?

Yes, metal stand will easily support the aquarium filled with 37.9  liters of seawater.

Explanation:

Maximum load taken by the metal stand = 450 lb

Load exerted by the aquarium filled with sea water :

Mass of an empty aquarium = 59.5 lb

Mass of sea water = m

Volume of sea water ,v= 37.9 L = 37900 mL

Density of the sea water = d = 1.03 g/mL

1 lb = 453.592  g

Total load exerted by filled aquarium = 86.062 lb + 59.5 lb = 145 .56 lb

450 lb > 145 .56 lb

Yes, metal stand will easily support the aquarium filled with 37.9  liters of seawater.

geosphere and hydrosphere.

this is because the geosphere has to do with geological events, while the hydrosphere controls all water on earth.

a corroding iron, if that's one of your choices