He2 has a bond order of 0, calculated as (2 bonding electrons - 2 antibonding electrons)/2 = 0.

H2 has a bond order of 1, calculated as (2 bonding electrons - 0 antibonding electrons)/2 = 1.

In PCl5, the phosphorus atom is dsp3 hybridized, resulting in a trigonal bipyramidal geometry.

In BrF5, bromine undergoes sp3d hybridization to form five bonds with fluorine and has one lone pair.

In BrF5, the bromine atom is sp3d2 hybridized, allowing it to form five bonds with fluorine.

BeCl2 has two bonding pairs and no lone pairs, resulting in a linear geometry.

NH3 has a trigonal pyramidal shape, which is not symmetrical due to the lone pair.

NH3 has three bonding pairs and one lone pair, resulting in a trigonal pyramidal shape.

SF4 has four bonding pairs and one lone pair, resulting in a seesaw molecular geometry.

SF4 has four bonding pairs and one lone pair, resulting in a seesaw shape.

SF4 has four bonding pairs and one lone pair, resulting in a seesaw shape.

XeF4 has four bonding pairs and two lone pairs, resulting in a square planar geometry.

CH4 has a tetrahedral shape due to the sp3 hybridization of the carbon atom.

CH4 has a tetrahedral shape due to the sp3 hybridization of the carbon atom.

PCl5 has five bonding pairs and no lone pairs, resulting in a trigonal bipyramidal geometry.

BF3 has a trigonal planar geometry due to sp2 hybridization of boron.

Chromium (Cr) has an electronic configuration of [Ar] 4s1 3d5, which means it has an incomplete d-subshell.

C2H2 has sp hybridization, with a triple bond between the two carbon atoms.

Argon has 18 electrons, and its electronic configuration is 1s2 2s2 2p6 3s2 3p6.

Bromine (Br) has the atomic number 35, and its configuration ends in 4p5.

The element with the configuration [Kr] 5s2 4d10 5p5 is Astatine.

The configuration [Kr] 5s2 4d10 5p5 corresponds to Astatine.

Mercury (Hg) has the electronic configuration [Xe] 4f14 5d10 6s2.

Bismuth (Bi) has the electronic configuration [Xe] 6s2 4f14 5d10.

Water has the highest boiling point due to strong hydrogen bonding between its molecules.

N2 has the highest bond order of 3 among the given options.

Fluorine has the highest electronegativity of all elements.

The configuration 1s2 2s2 2p6 3s2 3p5 (Chlorine) has the highest energy due to the presence of an unpaired electron.

Selenium (Se) has the highest energy electron in the 4p subshell with the configuration [Ar] 4s2 3d10 4p4.

CO2(g) has a higher enthalpy of formation compared to the elements in their standard states.