Question

Add electron dots and charges as necessary to show the reaction of potassium and bromine to form an ionic compound

Answer 1

Explanation: Electron dot structures are the lewis dot structures which represent the number of valence electrons around an atom in a molecule.

The electronic configuration of potassium is $[Ar]4s^1$

Valence electrons of potassium are 1.

The electronic configuration of Bromine is $[Ar]4s^24p^5$

Valence electrons of bromine are 7.

These two elements form ionic compound.

Ionic compound is defined as the compound which is formed from the complete transfer of electrons from one element to another element.

Here, one electron is released by potassium which is accepted by bromine element. In this process, Potassium becomes cation having +1 charge and Bromine become anion having (-1) charge.

The ionic equation follows:

$K^++Br^-\rightarrow KBr$

The electron dot structure is provided in the image below.

Answer 2

Answer:

Explanation:

1st) Look for the valence electrons of each element in the periodic table: Valence electrons are electrons in the latest shell of an atom and are the ones that can interact during a chemical reaction.

In this case, the potassium atom has 1 valence electron and the bromine atom has 7 valence electrons. (The electrons of potassium and bromine are shown in the attachment as cross and dot for better understanding).

2nd) Check which atom has more electronegativity:

The electronegativity is the capability that an atom has to attract to it the electrons of another atom during a chemical bond. If two atoms has a very high difference of electronegativity, it means that they will produce an ionic compund. Through the periodic table, electronegativity of elements increases from left to right in a period and increases from bottom to top in a group.

In this example, potassium atom is on the left side of the periodic table and bromine atom is in the right side, so bromine is much electronegative than potassium and it will take the valence electron of potassium.

3rd) Representation:

An ionic compound does not exactly form bonds but forms an crystalline structure where the most electronegative element attract to it the electrons of the less electronegative element.

So, we do not draw a bond in the final compound. The correct way of represent an ionic compound is to draw into parentheses each element.

In this case, potassium stays without its electron because bromine takes it, that's why potassium parentheses has no electrons and outside it we write a plus sign to show it lost 1 electrons.

In the same way, bromine has its 7 electrons and we add the electron it took from potassium, then we write a minus sing outside its parentheses because bromine atom has 1 extra electron now.

Note:

Remember that an ionic compound, as its name says, it is made from ionic atoms, so, it is important to represent it with ions.

In the example, potassium is the cation (ion with positive charge) and bromine is the anion (ion with negative charge).