The density is 3.144 g / cm^3.
<u>Explanation</u>:
If effective number of atom in NaCl type structure, z = 4
a = 705.2 pm ⇒ In centimeter = 705.2 
10^-10
Na = 6.023 10^23
density = (molecular weight) (z) / (Na) (a^3)
where molecular weight of KI is 166 g,
Z represents the atomic number
density = (molecular weight) (z) / (Na) (a^3)
= (166 4) / (6.023 10^23) (705.2 10^-10)
density = 3.144 g / cm^3.
Explanation: Oxygen plays a very vital role in the life of aquatic animals. The dissolved oxygen in the water helps them to breathe under water.
Optimum level of oxygen for deep living animals like oysters, bottom feeders, crabs is around (1-6 mg/L), while the animals living on the upper side like fishes require a higher amount of around (4-6 mg/L).
If the oxygen concentration in the pond is not optimum, there will no aquatic life and hence, the ecosystem will be affected.
Hence, oxygen concentration affects the fishes that live in the pond to a higher extent.
Answer: m Most likely Group2 metals and Group 17 non-ktta
Explanation:
A little more information is needed to be certain, but the likely answer is that X belongs to Group 2 and Y belongs to Group 17. Group 2 metals (Be, Mg, Ca, Sr, Ba, etc.) are all divalent. They gave rive up 2 electrons each to return to a full shell. Group 17 elements (e,g, F, Cl, Br, I, etc.) all require 1 electron to reach a full valence shell. That would make the proportion 1X to 2Y, or XY2. It is possible that a metal outside of Group 2 would also have a valency of 2. Iron(II) forms FeCl2, for example.
Protons, neutral, negatively, electrons
