primarily ionic include = sodium iodide( NaI) , calcium chloride ( CaCl2)
primarily covalent include - Ammonia (NH3) , Methane ( CH4) and
Glucose (C6H12O6)
Explanation
ionic bond is formed when there is complete transfer of electron between atoms. It occur between metal which donate electrons and a non metal which accept electrons.
for example in formation of CaCl2, ca donate 2 electron to 2 Cl atom, while 2 Cl atom accept the 2 electrons to form ionic bond.
Covalent bond is formed when two or more non metal form bond by sharing electrons pairs.
For example in NH3 3 pairs of electron are shared. to form covalent bond.
<span>NPK ratio system is a conventional shorthand for the ratio of the nitrogen N), phosphorus (P) and potassium (K) in a fertilizer. It actually shows amount of P</span>₂O₅.
If we use 100 kg of P₂O₅:
m(P₂O₅) = 0,15 · 100 kg.
m(P₂O₅) = 15 kg.
m(P₂O₅) : M(P₂O₅) = m(P) : 2M(P).
15 kg : 142 = m(P) : 62.
m(P) = 6,55 kg.
ω(P) = 6,55 kg ÷ 100 kg · 100% = 6,55%.
Explanation:
The given data is as follows.
Refractive index of mixture = 1.456
Refractive index of hexane = 1.375
Refractive index of toulene = 1.497
Let mole fraction of hexane =
and, mole fraction of toulene =
Also, 
or, 
Hence, calculate the mole fraction of hexane as follows.
refractive index mixture= mole fraction hexane × ref index hexane + mole fraction toluene × ref index toluene.
1.456 = 
1.456 = 
0.081 = 
= 
= 0.66
Since, 
= 1 - 0.66
= 0.34
Thus, we can conclude that mole fraction of hexane in your sample is 0.34.
<span>I would say D AlCl3.
covalent bonding is when 2 or more elements share electrons (usually when nonmetals bond with nonmetals)
ionic bonding is when one element steals another's electrons (usually when nonmetals bond with metals)</span>
8E24/6.022E23= 13.28 moles, where the denominator is Avagadro's number