Explanation:
Formula for work done is as follows.
W =
where, k = proportionality constant = 


d = separation distance = 0.45 nm = 
Now, we will put the given values into the above formula and calculate work done as follows.
W =
=
= 
Thus, we can conclude that work required to increase the separation of the two ions to an infinite distance is
.
Answer:
Explanation:
In KCL, the elements to combine to form KCl are K and Cl.
Potassium (K) is an element of group 1 and they're known to have 1 valence electron in its outer most orbital. This electron is donated and used for bonding. It is every element desirability to attain octet or duet electronic configuration I.e by having 2 electrons or 8 electrons in its outer orbital. Potassium has a lower electro negativity and higher ionization energy, hence it is easier to donate electron than to recieve it. Meanwhile, Chlorine (Cl) is an element of group 17 which are characterized for having 7 electrons in its outermost orbital requiring just one electron to form an octet configuration, chlorine has a higher electro negativity and lower ionization energy hence it is easier to accept electron than to donate it.
The nature of bond formed from K and Cl to give KCl is called electrovalent bonds.
Equation of reaction
K + Cl → KCl
There are 18 Elements in the fifth period.