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 
<span>Mantle convection is the slow creeping motion of Earth's rocky mantle caused by convection currents carrying heat from the interior of the earth to the surface. It is one of 3 driving forces that causes tectonic plates to move around the Earth's surface.</span>
The number of moles of iron produced can be obtained by the use of stoichiometry.
<h3>What is stoichiometry?</h3>
The term stoichiometry has to do with mass - mole or mass - volume relationships. Stoichiometric relationships could be used to determine the amount of substance.
Now the reaction equation as well as other details are not shown in this question hence a numerical anwer can not be provided. As such, we can know that the balanced reaction equation can always be used to obtain the amount of iron by stoichiometry.
Learn more about stoichiometry: brainly.com/question/9743981
Answer: covalent bond
Explanation: Yeah that's the answer
Central Vacuole in plant cells:
- holds materials and wastes.
- provide structure and support for the growing plant.
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