The mercury content of a stream was belived to be above the minimum considered safe part per billion (ppb) by weight. an analysis indicated that the concentration was 0.68 parts per billion. what quantity of mercury in grams was persent in 15.0 l of the water, the density of which is 0.998 g/ml? (1 ppb hg = 1nghg/1g water)

Quantity of Hg in 15.00 L water = 1.0*10^-5 g

Explanation:

Given:

Concentration of Hg = 0.68 parts per billion (ppb)

Volume of water = 15.0 L

Density of water = 0.998 g/ml

To determine:

The amount of Hg in 15.0 L of water

Calculation:

1 ppb = 1 nanogram (ng) solute/1 g water

1 ng = 10⁻⁹ g

0.68 ppb = 0.68 ngHg/1 g water = 0.68*10⁻⁹g Hg/ 1g water

The amount of Hg in the above mass of water would be:

=

a pan containing water is placed in a positio n where it is exposed to a 10 mile per hour wind. the pan contains a uniform depth of 1.27 cm of water, is quite wide, and has a length of 2.44 m in the wind direction. the water in the pan is at a constant temperature of 15.5 °c.

the answer is b because, investigating whether another species of moth also drinks tears might be interesting, but it would not directly explain why this species of moth does.

to explain why this species of moth drinks tears, the scientist could ask: "what nutrients that moths need are in elephant tears? "

the scientist could experiment with moth repellent or oter ways to keep the moths away, but that would not answer his original question.