Question

how the property of hydrogen and iron is similar​

Answer 1

Hydrogen is the first element on the periodic table of elements. The periodic table is designed so that elements with like properties are in the same column. What makes the elements similar is the fact that all of the ones in the same column have an equal number of valence electrons. Since hydrogen is the very first element in the table, the four elements with the most similar properties to hydrogen will be the next four down the column.