## Key difference - sp vs. sp ^{2} vs. sp ^{3} hybridization

Orbitals are hypothetical structures that can be filled with electrons . Based on various discoveries, scientists have proposed different shapes for these orbitals. There are three main types of orbitals: atomic orbitals , molecular orbitals, and hybrid orbitals . Atomic orbitals of an atom are hybridized to create suitable orbitals for chemical bonding. In chemistry, hybridization is the mixing of different atomic orbitals to form hybrid orbitals. There are different forms of hybridizations that make different forms of hybrid orbitals such as sp, sp ^{2,} and sp ^{3} hybrid orbitals. These orbitals arise from the hybridization of s and p atomic orbitals in different ratios. The main difference between sp sp ^{2} and sp ^{3} hybridization is that **sp hybridization forms hybrid orbitals with 50% s orbital properties and sp ^{2} hybridization forms hybrid orbitals with 33% s orbital properties, while sp ^{3} hybridization forms hybrid orbitals with 25% s orbital properties.**

### Key areas covered

**1. What is sp hybridization** *- definition, calculation of S and P properties, other functions* **2. What is sp ^{2} hybridization**

*- definition, calculation of S and P properties, other functions*

**3. What is sp**

^{3}hybridization*- Definition, calculation of S and P properties, further characteristics*

**4. What is the difference between sp sp**

^{2}and sp^{3}hybridization*- comparison of the most important differences*

*Key Terms: Atomic Orbitals, Hybrid Orbitals, Hybridization, Orbitals, Sp Hybridization, Sp ^{2} Hybridization, Sp ^{3} Hybridization*

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## What is sp hybridization?

sp hybridization is the hybridization that takes place between an s atomic orbital and a p atomic orbital. An electron shell contains three p orbitals. Therefore, after the hybridization of an s orbital with one of these p orbitals, there are two unhybridized p orbitals in this atom. We consider all s and p orbitals as pure atomic orbitals (s + p). The ratio between s and p orbitals is 1: 1. Therefore, the proportion of the s orbitals is 1/2 and the proportion of the p orbitals is 1/2.

S (or p) characteristic percentage = total atomic orbitals x (1/2) x 100% = 50%

The resulting hybrid orbitals have 50% s properties and 50% p properties. Since only two hybrid orbitals have formed, the spatial arrangement of the sp orbitals is linear. The two hybrid orbitals are directed in opposite directions. Hence the angle between these orbitals is 180 ^{o} C.

## What is sp ^{2} hybridization?

sp ^{2} hybridization is the mixing of one s atomic orbitals with two p atomic orbitals. The newly formed hybrid orbitals are referred to as sp ^{2} hybrid orbitals. The resulting hybrid orbitals have about 33.33% s characters and about 66.66% p characters. This is because a total of three atomic orbitals are involved in hybridization and the percentages of the s and p properties vary as follows.

Here we consider all s and p orbitals as pure atomic orbitals (s + p + p). The ratio between s and p orbitals is 1: 2. Therefore the proportion of the s orbital is 1/3 and the proportion of the p orbitals 2/3.

S characteristic percentage = total atomic orbitals x (1/3) x 100% = 33.33% P characteristic percentage = total atomic orbitals x (2/3) x 100% = 66.66%

The spatial arrangement of the sp ^{2} hybrid orbitals is trigonal-planar. Therefore, the angle between these orbitals is ^{o} C. 120 the atoms that undergo this hybridization 1 unhybridized p - orbital, because only two out of three p - orbitals are involved in this hybridization.

## What is sp ^{3} hybridization?

sp ^{3} hybridization is the mixing of one s atomic orbitals with three p atomic orbitals. Here the atoms do not have any unhybridized p orbitals, since all three p orbitals are involved in the hybridization. The resulting orbitals are referred to as sp ^{3} hybrid orbitals. As for sp ^{2} orbitals, we can calculate the s and p characteristics of these orbitals.

In sp ^{3} hybridization, we consider all s and p orbitals to be atomic orbitals only (s + p + p + p). The ratio between s and p orbitals is 1: 3. Therefore the part of the s orbital is ¼ and the part of the p orbitals is ¾.

S characteristic percentage = total atomic orbitals x (1/4) x 100% = 25% p characteristic percentage = total atomic orbitals x (3/4) x 100% = 75%

These orbitals are formed when one s orbital and 3 p orbitals are hybridized. The resulting hybrid orbitals have about 25% s-signs and about 75% p-signs. The spatial arrangement of these orbitals is tetrahedral. Hence the angle between these orbitals is 109.5 ^{o} C.

## Difference between sp sp ^{2} and sp ^{3} hybridization

### definition

**sp hybridization:** sp hybridization is the hybridization that takes place between an s atomic orbital and a p atomic orbital.

**sp ^{2} hybridization:** sp

^{2}hybridization is the mixing of one s atomic orbitals with two p atomic orbitals.

**sp ^{3} hybridization:** sp

^{3}hybridization is the mixing of an s atomic orbitals with three p atomic orbitals.

### S properties

**sp hybridization:** the s characteristic percentage of sp hybrid orbitals is 50%.

**sp ^{2} hybridization:** the s-characteristic percentage of sp

^{2}hybrid orbitals is 33.33%.

**sp ^{3} hybridization:** the s-characteristic percentage of sp

^{3}hybrid orbitals is 25%.

### P Characteristic percentage of hybrid orbitals

**sp hybridization:** the p-characteristic percentage of sp hybrid orbitals is 50%.

**sp ^{2} hybridization:** the p-characteristic percentage of sp

^{2}hybrid orbitals is 66.66%.

**sp ^{3} hybridization:** the p-characteristic percentage of sp

^{3}hybrid orbitals is 75%.

### Angle between orbitals

**sp hybridization:** the angle between the sp orbitals is 180 ° C.

**sp ^{2} hybridization:** the angle between the sp

^{2}orbitals is 120 ° C.

**sp ^{3} hybridization:** the angle between the sp

^{3}orbitals is 109.5 ° C.

### geometry

**sp hybridization:** The geometry of the orbital arrangement in sp hybridization is linear.

**sp ^{2} hybridization:** The geometry of the orbital arrangement in sp

^{2}hybridization is trigonal-planar.

**sp ^{3} hybridization:** The geometry of the orbital arrangement in sp

^{3}hybridization is tetrahedral.

### Number of unhybridized orbitals

**sp hybridization:** Sp hybridization results in two unhybridized p orbitals.

**sp ^{2} hybridization:** Sp

^{2}hybridization results in an unhybridized p orbital.

**sp ^{3} hybridization:** Sp

^{3}hybridization does not lead to unhybridized p orbitals.

### diploma

Hybridization in chemistry stands for the mixing of different atomic orbitals to form new hybrid orbitals with different properties. Sp, sp ^{2} and sp ^{3} hybridizations are such examples. The main difference between sp, sp ^{2} and sp ^{3} hybridization is that the sp - hybridization forms -hybrid orbitals 50% s - orbital properties and sp ^{2} -hybridization forms hybrid orbitals while 33% s - orbital properties sp ^{3} -hybridization forms hybrid orbitals with 25% s - orbital properties.

##### Reference:

1. "Hybrid Orbitals". Chemistry LibreTexts, Libretexts, July 21, 2016, available here . “Orbital Hybridization.” Wikipedia, Wikimedia Foundation, January 15, 2018, available here .

##### Image courtesy:

1. “Hybrydyzacja sp” By Joanna Kośmider - Own work (Public Domain) via Commons Wikimedia 2. “Hybrydyzacja sp2” By Joanna Kośmider - Own work (Public Domain) via Commons Wikimedia 3. “Hybrydyzacja sp3” By Joanna Kośmider - Own work (Public Domain) via Commons Wikimedia