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 
It would be B because you want to know which TEMPERATURE is the best for the plant. Different brightness for a bulb will give different amounts of heat. Since the amount of heat is your INDEPENDENT VARIABLE, you have to change the amount of heat for each plant, so the brightness of bulbs. Therefore, B is your answer!
Answer:
No
Explanation:
The chemical reaction between magnesium metal and hydrochloric acid solution is not an acid - base reaction.
An acid - base reaction involves an acid and base to produce salt and water.
- This reaction is called a neutralization reaction.
- An acid is a substance that produces excess hydroxonium ions in solutions.
- A base produces excess hydroxyl ions in solution.
- When acids and base combines, the main product is a salt in water solution.
They often create data tables, charts, or graphs to easily communicate results.
An ionic compound is made up of a metal and a nonmetal. This eliminates answer choice A, C, and D because both of the elements listed are nonmetal.
Your correct answer is B) One atom of calcium and two atoms of chlorine. This is because calcium is a metal, and chlorine is a nonmetal.
