How does hydrogen resemble the group 17 elements of the periodic table?
How does hydrogen resemble the group 17 elements of the periodic table?
Resemblance with halogens(Group -17 or Group VII)---
(1) Electronic configuration: all halogens have 7 electrons in their respective outermost shell and thus have one less electron than the stable configuration of nearest noble gas. Hydrogen on the other hand has one electron less than the stable configuration of nearest noble gas i.e. Helium.
2) Electronegative character: halogens have a strong tendency to gain one electron to form halide ions, similarly, hydrogen shows some tendency to gain one electron to form hydride ion.
H+e−→H− (He gas configuration)
Cl+e−→Cl− (Ar gas configuration)
(3) The ionization energy of hydrogen is similar to that of halogens but much higher than alkali metals.
for example ionizaion energy of H = 1312 kj/mole
ionization energy of F(a halogen) = 1681 kj/mole
ionization energy of Cl(a halogen) = 1255 kj/mole
ionization energy of Na (an alkali metal) = 496 kj/mole
the ionizaion energy of K (an alkali metal) = 419 kj/mole
(4)oxidation state: Just like halogens, hydrogen shows an oxidation state of -1.
for example -- NaH like NaCl (both hydrogen and chlorine are in -1 oxidation state)
(5)Like halogens, hydrogen easily combines with non -metal such as carbon, silicon, nitrogen etc to form covalent compounds.
With hydrogen: CH4,SiH4,NH3
With halogens: CCl4,SiCl4,NCl3
Resemblance with halogens(Group -17 or Group VII)---
(1) Electronic configuration: all halogens have 7 electrons in their respective outermost shell and thus have one less electron than the stable configuration of nearest noble gas. Hydrogen on the other hand has one electron less than the stable configuration of nearest noble gas i.e. Helium.
2) Electronegative character: halogens have a strong tendency to gain one electron to form halide ions, similarly, hydrogen shows some tendency to gain one electron to form hydride ion.
H+e−→H− (He gas configuration)
Cl+e−→Cl− (Ar gas configuration)
(3) The ionization energy of hydrogen is similar to that of halogens but much higher than alkali metals.
for example ionizaion energy of H = 1312 kj/mole
ionization energy of F(a halogen) = 1681 kj/mole
ionization energy of Cl(a halogen) = 1255 kj/mole
ionization energy of Na (an alkali metal) = 496 kj/mole
the ionizaion energy of K (an alkali metal) = 419 kj/mole
(4)oxidation state: Just like halogens, hydrogen shows an oxidation state of -1.
for example -- NaH like NaCl (both hydrogen and chlorine are in -1 oxidation state)
(5)Like halogens, hydrogen easily combines with non -metal such as carbon, silicon, nitrogen etc to form covalent compounds.
With hydrogen: CH4,SiH4,NH3
With halogens: CCl4,SiCl4,NCl3
