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 
50x75=3750 -- metres per day
3750x15=56250 -- metres in 15 days
Divide by 1000 to convert to km
56.250km
<u>56.25km</u>
1. D
2. <span>83.5 million years ago - 66 million years ago
3. </span><span>It had armor and could rotate to keep its caudal bludgeon facing the enemy.
hope this helped :)
alisa202</span>
Answer: Among the listed substances
is the molecular compound.
Explanation:
A chemical compound formed by the chemical combination of two or more non-metals is called a molecular compound or covalent compound.
For example, Xe and Cl are non-metals. The compound formed by them is
which is a molecular compound.
A molecular compound is formed by sharing of atoms between the combining atoms.
Whereas NaF,
and CaO are all ionic compounds as they are formed by chemical combination of a metal and a non-metal.
Thus, we can conclude that among the listed substances
is the molecular compound.