The rule for hybridization: All sigma bonds (single bonds and only one bond in double or triple bonds) and lone pairs (nonbonding pairs) are found in hybrid orbitals. We understand from this statement that hybrib orbitals cannot form pi bonds.
Boron (B) (atomic no:5) has 3 valence electrons and form 3 single bonds and no pi bond. Therefore it is impossible for B to make bonds without hybridization.
Nitrogen (N) (atomic no: 7) has 5 valence electrons. Normally it can form 3 sigma bonds to complete its octet. Note that although B also have 3 sigma bonds it can not complete its octet. In such a case nitrogen can not form any bond without hybridization like in the case of ammonia NH3. Together with the non bonding pair of N , the type of hybridization of N is sp3 when all the bonds of N are single (sigma) bonds.
On the other hand , N can be form 1 double bond like in the case of nitrate ion, NO3^-. 2 of the O atoms are bound to N by single bonds and one O atom is bound to N atom by a double bond (one sigma and one pi). In such a case since pi bonds are formed without hybridization, 2 of the bonds of N are formed by hybridization and 1 of them is formed without hybridization. Together with the non bonding pair of N , the type of hybridization of N is sp2 when it forms one double bond.
In some cases N can form a triple bond, like in the case of cyanate ion CN^-. There is a triple bond between C and N atoms. One of them is sigma the others are pi bonds. This time 2 bonds are formed without hybridization. Together with the non bonding pair of N , the type of hybridization of N is sp when it forms one triple bond.
Oxygen (O) (atomic no: 8) has 6 valence electrons. Normally it can form 2 sigma bonds to complete its octet. In such cases oxygen can not form any bond without hybridization like in the case of ammonia H2O. Together with the two non bonding pair of O , the type of hybridization of O is sp3 when all the bonds of O are single (sigma) bonds.
However , O can be form 1 double bond like in the case of ozone molecule, O3 . 1 of the O atoms are bound to the central O atom by a single bond and the other O atom is bound to Central O atom by a double bond (one sigma and one pi). Since pi bonds are formed without hybridization, 2 of the bonds of O are formed by hybridization and 1 of them is formed without hybridization. Together with the non bonding pair of O , the type of hybridization of O is sp2 when it forms one double bond.
Remark: As you may notice, in H2O, O has two nonbonding pairs, but in O3, the central O has 1 nonbonding pair. One of them is used to make a coordinate covalent (dative) bond with the O atom to form a single bond by completing its octet vacancy.
As a summary; When N forms a double bond, 1 bond (1 pi)
When N forms a triple bond, 2 bonds (2 pi)
When O forms a double bond, 1 bond (1 pi)
cannot be made by by hybridization.
O cannot form a triple bond.
Boron can make three bonds without hybridization, as it has three valence electrons to use for bonding.
Calcium can make bonds without hybridization because it has an s2 electron configuration. It can typically form ionic bonds by losing its two valence electrons to achieve a stable octet configuration.
A Ca atom in its 4s^2 electron configuration can make up to 2 bonds without hybridization. This is because it has two unpaired electrons in its 4s orbital available for bonding.
Aluminum can make three bonds without hybridization because it has three valence electrons in its 3s and 3p orbitals. Its electron configuration is 1s2 2s2 2p6 3s2 3p1.
Mg in the 3s^2 configuration can form up to two bonds without hybridization. This is because it has two valence electrons in its 3s orbital, allowing it to form two bonds by losing or sharing these electrons.
Boron can make three bonds without hybridization, as it has three valence electrons to use for bonding.
Calcium can make bonds without hybridization because it has an s2 electron configuration. It can typically form ionic bonds by losing its two valence electrons to achieve a stable octet configuration.
A Ca atom in its 4s^2 electron configuration can make up to 2 bonds without hybridization. This is because it has two unpaired electrons in its 4s orbital available for bonding.
Aluminum can make three bonds without hybridization because it has three valence electrons in its 3s and 3p orbitals. Its electron configuration is 1s2 2s2 2p6 3s2 3p1.
Mg in the 3s^2 configuration can form up to two bonds without hybridization. This is because it has two valence electrons in its 3s orbital, allowing it to form two bonds by losing or sharing these electrons.
P3s23p3 has a total of 5 valence electrons, so it can form up to 3 bonds without hybridization by sharing these electrons with other atoms. Each bond requires 2 electrons to form.
Chlorine can make one single bond without hybridization. It has 7 valence electrons, needing just one more to fill its octet. By sharing one electron with another atom, it completes its octet and achieves stability.
Each atom can make three bonds without hybridization: one bond with each of the three unpaired p orbitals. Additionally, each atom can participate in 1 sigma bond and 2 pi bonds.
Without hybridization, oxygen has a valence electron configuration of 2s22p4. Which means it has 2 unpaired electrons; therefore it can form 2 bonds.
Calcium can form the ion Ca2+ and forms many ionic compounds. Hybridisation would indicate we were talking about covalent bonding, calcium is not good at this, for example organo-calcium compounds are much more unstable than magnesium.
it can make covalent bonds!
Carbon can make 4 bonds with hydrogen. Nitrogen can make 3 bonds with hydrogen. Oxygen can make 2 bonds with hydrogen.