Answer:
B
Explanation:
so that way they can hide away from the predators
1. electrostatic interactions
<span>3. van de waals interactions </span>
<span>4. hydrogen bonding </span>
The silver chloride electrode usually functions as a redox electrode where the equilibrium is achieved between silver and its salt (silver chloride).
The half reaction for this electrode is as follow:
<span>AgCl(s)+e−→Ag(s)+Cl−(aq) where:
</span>(s) refers to solid state
(aq) refers to the aqueous state and
e- is the electron
.
Oxygen-16 is the atom in question.
- Atomic number: 8.
- Mass number: 16.
<h3>Explanation</h3>
The superscript of the ion says "2-". That means that the ion here carries a charge of -2.
- The charge is negative, meaning that there are more electrons (which are negative) than protons (which are positive) in that ion.
- The size of the charge is 2. There are two more electrons than protons in that ion.
There are 10 electrons in total in that ion. There are two more electrons than protons. That means that there are 10 - 2 = 8 protons in that ion.
The atomic number of an atom is the same as its number of protons. The atomic number of X is 8.
The atomic number determines the element. Atomic number 8 is oxygen. Thus element X is oxygen.
Mass number is the sum of number of protons and neutrons in an atom. 8 + 8 = 16 for this atom.

☃️ Chemical formulae ➝ 
How to find?
For solving this question, We need to know how to find moles of solution or any substance if a certain weight is given.

Solution:
❍ Molecular weight of 
= 2 × 126.90
= 253.80
= 254 (approx.)
❍ Given weight: 12.7
Then, no. of moles,
⇛ No. of moles = 12.7 / 254
⇛ No. of moles = 0.05 moles
⚘ No. of moles of Iodine molecule in the given weight = <u>0.05</u><u> </u><u>moles </u>
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