White tern catches fish including crustaceans, flying fish, squid, and others. Prior of plunging into water, it hovers initially over the water surface and then either dives or dips in the surface, without getting entirely submerged into water, and catches its target.

The food or fish is captivated in its small, however, sharp black beak that is specific as it bent upwards and tapers to a sharp point. It also possesses a long slender body with tapering, long wings, all of which encourage its diving or dipping activity into the surface of the water.

7 0

4 years ago

Fluoride ion is poisonous in relatively low amounts: 0.2 g of F- per 70 kg of body weight can cause death. Nevertheless, in orde

svetoff [14.1K]

Answer:

$\boxed{\text{(a) 14 L; (b) 711 kg}}$

Explanation:

(a) Litres of water

$\text{Mass of F}^{-} = 8.5 \times 10^{7}\text{ gal} \times \dfrac{\text{0.2 mg F}^{-}}{\text{1 kg}} = \textbf{14 mg F}^{-}\\\\\text{Volume of water} = \text{14 mg F}^{-} \times \dfrac{\text{1 L water}}{\text{1 mg F}^{-}} = \textbf{14 L water}\\\\\text{The person would have to consume $\boxed{\textbf{14 L}}$ of water per day}$

(b) Mass of NaF

$\text{Volume} =8.5 \times 10^{7} \text{gal} \times \dfrac{\text{3.785 L}}{\text{1 gal}} = 3.22 \times 10^{8}\text{ L}\\\\\text{Milligrams of F}^{-} = 3.22 \times 10^{8}\text{ L} \times \dfrac{\text{ 1 mg F}^{-}}{\text{1 L}} = 3.22 \times 10^{8}\text{ mg F}^{-}\\\\\text{kilograms of F}^{-} = 3.22 \times 10^{8}\text{ mg F}^{-} \times \dfrac{\text{1 mg F}^{-}}{10^{6}\text{kg F⁻}} = \text{322 kg F}^{-}$

1 kmol of NaF (41.99 kg) contains 19.00 kg of F⁻.

$\text{Kilograms of NaF}= \text{322 kg F}^{-} \times \dfrac{\text{41.99 kg NaF}}{\text{19.00 kg F}^{-}} = \text{711 kg NaF}\\\\\text{It will take } \boxed{\textbf{711 kg}} \text{ of NaF to treat the reservoir}$

7 0

4 years ago

Read 2 more answers

Mrs. Stark weighs 70kg. How much Potential Energy does she have if she stands on the roof of an 80m tall building?

8_murik_8 [283]

E = mgh

E = 70*9.81*80

E = 54936 J

5 0

4 years ago

Which of the following is true about the Lewis structure of NF3? Really need help

Ganezh [65]

Answer:

All of the above.

Explanation:

Hello there!

In this case, according to the definition of the Lewis structures, which are represented by the valence electrons, we first identify that the N atom has five valence electrons and each fluorine has seven valence electrons.

In such a way, we cans say that N is the central atom due to its lower electronegativity, the molecule has 7+7+7+5=26 valence electrons and the three F-N bonds are covalent, therefore the answer is all of the above.

Regards!

7 0

3 years ago