# Atomic Orbitals

Electrons in an atom don't travel in circles, but rather form a probability cloud: from the 1s to the f orbitals, look at the shapes of these clouds\.

By Darion Wells

Topic: Physics & Chemistry

[Open the interactive Jig](https://ask.jig.com/j/CxdNhFjQKAIu)

## Transcript

### 1. Atomic orbitals: clouds of electrons

At the very centre of an atom sits a tiny nucleus, with electrons around it\. Electrons do not race around fixed circles like planets\. We can only know where one is likely to turn up, and when we draw those chances we get a cloud called an atomic orbital\.

Press an empty spot and drag to see the cloud from every side\.

### 2. Found at one point at a time

Each time we look for the electron, it shows up at just one point\. Stack thousands of those results together: where the dots are thickest, the electron turns up most often\. Hydrogen's simplest orbital is called 1s, and it looks like a fuzzy ball\.

The faint circle is the old "planet" picture of the atom\. A 1s electron is most likely to be found about 0\.053 nanometres from the nucleus, exactly the radius of that circle\.

### 3. A bigger ball: the 2s orbital

Electrons with more energy have bigger clouds\. The 2s orbital is round too, but it hides a thin shell inside where the electron is almost never found, called a node\. The two colours show the two phases of the electron wave, like the crests and troughs of a water wave\.

The colours do not mean positive or negative charge\. They only show the phase of the wave\.

### 4. Dumbbell shapes: p orbitals

From the second shell on, p orbitals appear\. Each looks like a dumbbell: two lobes of cloud split by a flat plane through the nucleus, where the electron is never found\. There are three p orbitals, pointing along the x, y and z directions\.

Each orbital holds at most two electrons, so the three p orbitals hold up to 6\.

### 5. Four\-leaf clovers: d orbitals

From the third shell on, d orbitals appear, five in all\. Four of them look like four\-leaf clovers\. The fifth has two lobes, one above and one below, with a ring around its waist\. In a hydrogen atom, all five have exactly the same energy\.

The five d orbitals hold up to 10 electrons\.

### 6. More petals: f orbitals

In the fourth shell, seven f orbitals appear\. They have even more petals, some as many as eight, separated by three nodal planes\. The more complex the shape, the more empty gaps the cloud has\.

The seven f orbitals hold up to 14 electrons\.

### 7. Orbitals and the periodic table

The s, p, d and f types have 1, 3, 5 and 7 orbitals\. Each orbital holds at most two electrons, so they fit 2, 6, 10 and 14 electrons\. Those are exactly the widths of the s, p, d and f blocks of the periodic table\.

How atoms join up into molecules also depends on the shapes of these electron clouds\.