<Dd> 2 S + 1 Λ (v) (\ displaystyle ^ (2S + 1) \ Lambda (v)) </Dd> <P> where S (\ displaystyle S) is the total electronic spin quantum number, Λ (\ displaystyle \ Lambda) is the total electronic angular momentum quantum number along the internuclear axis, and v (\ displaystyle v) is the vibrational quantum number . Λ (\ displaystyle \ Lambda) takes on values 0, 1, 2,..., which are represented by the electronic state symbols Σ (\ displaystyle \ Sigma), Π (\ displaystyle \ Pi), Δ (\ displaystyle \ Delta),.... For example, the following table lists the common electronic states (without vibrational quantum numbers) along with the energy of the lowest vibrational level (v = 0 (\ displaystyle v = 0)) of diatomic nitrogen (N), the most abundant gas in the Earth's atmosphere . In the table, the subscripts and superscripts after Λ (\ displaystyle \ Lambda) give additional quantum mechanical details about the electronic state . </P> <Table> <Tr> <Th> State </Th> <Th> Energy (T 0 (\ displaystyle T_ (0)), cm) See note below </Th> </Tr> <Tr> <Td> X 1 Σ g + (\ displaystyle X ^ (1) \ Sigma _ (g) ^ (+)) </Td> <Td> 0.0 </Td> </Tr> <Tr> <Td> A 3 Σ u + (\ displaystyle A ^ (3) \ Sigma _ (u) ^ (+)) </Td> <Td> 49754.8 </Td> </Tr> <Tr> <Td> B 3 Π g (\ displaystyle B ^ (3) \ Pi _ (g)) </Td> <Td> 59306.8 </Td> </Tr> <Tr> <Td> W 3 Δ u (\ displaystyle W ^ (3) \ Delta _ (u)) </Td> <Td> 59380.2 </Td> </Tr> <Tr> <Td> B ′ 3 Σ u − (\ displaystyle B' ^ (3) \ Sigma _ (u) ^ (-)) </Td> <Td> 65851.3 </Td> </Tr> <Tr> <Td> a ′ 1 Σ u − (\ displaystyle a' ^ (1) \ Sigma _ (u) ^ (-)) </Td> <Td> 67739.3 </Td> </Tr> <Tr> <Td> a 1 Π g (\ displaystyle a ^ (1) \ Pi _ (g)) </Td> <Td> 68951.2 </Td> </Tr> <Tr> <Td> w 1 Δ u (\ displaystyle w ^ (1) \ Delta _ (u)) </Td> <Td> 71698.4 </Td> </Tr> </Table> <Tr> <Th> State </Th> <Th> Energy (T 0 (\ displaystyle T_ (0)), cm) See note below </Th> </Tr>

Which element in period 3 exists as diatomic molecules at stp