Amarine aquarium is found to contain a salt concentration of 40 ppt. how many grams of salt are in one liter of the solution?

40 grams of salt/L
In this case the question is using ppt unit which withstand for part per thousand. That mean 40 ppt of salt is having concentration of 40/1000 or 4/100. One liter of water has 1000 gram mass. That mean the salt weight is : 4/100 x1000 grams= 40 mg.

Because the earth is not round ,but it may seem round when viewed from ,our planet but true some points earth is not round was an oblate spheroid -a square that it squashed as globe however is not even a perfect oblate spheroid.in fact isaac newton's first proposed that earth was not perfectly round but it was an oblate spheroid instead.that mean a square that is squashed as its poles and swollen at the

Iwould say overuse ( but not 100% sure ) in the u.s. we tend to overuse water by leaving it running, throwing it away, taking long showers, etc.