What is Bredigs arc method?

Hint: As we know that in chemistry, periodic tables play a vital role. In the periodic table there are totally \[118\] elements. In the periodic table there are totally \[18\] columns and \[7\] rows. The columns are called groups. Hence, \[18\] groups in the periodic table. The rows are called periods. Hence, totally \[7\] period in the table. The atomic number of iron is \[26\] and the symbol is \[{\text{Fe}}\]. The mass number of the iron is \[55.845\]. Gold is one of the transition elements in the periodic table. The atomic number of gold is \[79\] and the mass number of gold is \[196.967\]. The symbol of gold is \[{\text{Au}}\].The symbol of silver is \[{\text{Ag}}\]. The atomic number of silver is \[47\]. The mass number of silver is \[107.868g\]. The symbol of platinum is \[{\text{Au}}\].The symbol of silver is \[{\text{Pt}}\]. The atomic number of platinum is \[78\]. The mass number of platinum is \[195.08\].

Complete answer:
We have to know that the preparation of colloidal solution of metals like gold, silver and platinum by using potassium hydroxide is known as the Bredig arc method. In this method iron is not able to form colloidal solutions.

Note:
As we know, the atomic number of the atom depends on the number of protons or the number of electrons. The atomic number of the atom is equal to the number of protons or the number of the electrons. The mass number of the atom depends on the number of protons and the number of neutrons. The mass number of the atom is equal to the sum of the number of protons and the number of neutrons in the atom. Each element in the periodic table has a certain group and period.