Question

Write the formula of the product formed when element A (atomic number 19) combines with element B (atomic number 17). Draw its electronic dot structure. What is the nature of the bond formed?

Answer 1

Step 1: Identifying the elements with given atomic numbers

Element A: Given Atomic no = $19$

• By looking at the periodic table we conclude the element is potassium ($\mathrm{K}$).
• Electronic configuration = ($2,8,8,1$)

Element B : Given Atomic no = $17$

• By looking at the periodic table we conclude the element is chlorine ($\mathrm{Cl}$)
• Electronic configuration = ($2,8,7$)

Step 2: Chemical reaction of elements A and B

• Potassium combines with chlorine to form potassium chloride because Potassium loses one electron to attain noble gas configuration and chlorine gains one electron to attain noble gas electronic configuration.
• $\underset{\mathrm{Potassium}}{2\mathrm{K}\left(\mathrm{s}\right)}+\underset{\mathrm{Chlorine}}{{\mathrm{Cl}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Potassium}\mathrm{chloride}}{2\mathrm{KCl}\left(\mathrm{s}\right)}$

• So lewis dot structure for $\mathrm{KCl}$ is

Step 3: Analyzing the bond between $\mathrm{KCl}$

• Since the bond is formed between potassium and chlorine by the complete transfer of electrons. So, the nature of the bond is ionic.