Answer: the first one is adaptation, third is migration, 4th is hibernation,
Explanation:
i dont know the other ones, sorry because i am also a 7th grader.
Answer: 1. C. polar covalent: electrons shared between silicon and sulfur but attracted more to the sulfur
2. B) 
3. B) Fluorine
Explanation:
1. A polar covalent bond is defined as the bond which is formed when there is a difference of electronegativities between the atoms.
Electronegativity difference = electronegativity of sulphur- electronegativity of silicon = 2.5 -1.8 = 0.7
Thus as electronegativity difference is less than 1.7 , the cond is polar covalent and as electronegativity of sulphur is more , the electrons will be more towards sulphur.
2. A molecular compound is usually composed of two or more nonmetal elements. Example:
Ionic compound is formed by the transfer of electrons from metals to non metals. Example:
,
and 
3. For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here K is having an oxidation state of +1 and as the compound formed is KZ, the oxidation state of non metallic element Z should be -1. Thus the element Z is flourine which exists as diatomic gas 
Answer: 
Explanation:
pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration.
![pH=-\log [H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D)

Putting in the values:

![5.29=-log[H^+]](https://tex.z-dn.net/?f=5.29%3D-log%5BH%5E%2B%5D)
![[H^+]=5.1\times 10^{-6}](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D5.1%5Ctimes%2010%5E%7B-6%7D)
Thus
is 
Perchloric acid (HCO₄) is one of strongest inorganic acids. Perchloric acid precipitation is used to removes most of the protein present in the
sample and stabilize many of the small molecule analytes. It can use also to precipitation glycogen, ATP, glutathione, antioxidants.
Perchloric acid donates protons to macromolecules and lower their solubility in water. Also perchloric acid is strong oxidizing agent and change oxidation number of elements.