An ionic compound is composed of ionic bonds that are formed by transfer of electrons from one atom to the other. The atom that loses electrons acquires a positive charge (cation) while that which gains electrons acquires a negative charge.
In the case of sodium chloride; Sodium Na has 1 electron in its outer orbital while Chlorine Cl has 7 electrons. Thus, Cl requires 1 electron to complete its octet. This electron is donated by Na.
Thus, NaCl is essentially, Na⁺Cl⁻
Ans D) Chlorine becomes an anion by gaining an electron from sodium
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: I think it’s B. Because as you can see from the picture there are layers
Explanation:
I think but just in case ask for a second opinion
Answer: atoms
Explanation:
All matter is made up of smaller indivisible particles called atoms. These atoms are the smallest units of matter ACCORDING to the Dalton's Atomic theory.
Molecules are combined atoms, while cells and phospholipids are complex combination of atoms.
Therefore, atoms is the answer