Astatine Bohr model

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The astatine Bohr model has a nucleus with 85 protons and 125 neutrons. Orbiting this nucleus are six electron shells, holding a total of 85 electrons.

To draw the astatine Bohr model, outline the 85 protons, 125 neutrons, and 85 electrons. Start by illustrating the nucleus, and then draw the six electron shells. The first five shells should contain 2, 8, 18, 32, and 18 electrons, respectively, while the sixth shell holds the remaining 7 electrons.

Steps

Find protons, neutrons, and electrons of astatine atom

Astatine has 85 protons, 125 neutrons, and 85 electrons.

Astatine protons

• Protons = atomic number

From the periodic table, find the atomic number of astatine.

The atomic number of astatine is 85. Hence, astatine has a total of 85 protons.

Astatine neutrons

• Neutrons = atomic mass – atomic number

The atomic mass of astatine is 210 and the atomic number of astatine is 85.

Subtract the atomic number (85) from the atomic mass (210). Hence, astatine has a total of 210 – 85 = 125 neutrons.

Astatine electrons

• Electrons = atomic number

The atomic number of astatine is 85. Hence, astatine has a total of 85 electrons.

Draw nucleus of astatine atom

The nucleus of an astatine atom contains 85 protons and 125 neutrons. So draw the nucleus of astatine atom as follows:

Now in the next step, draw the 1^st electron shell and start marking electrons.

Draw 1^st electron shell

Remember that we have a total of 85 electrons.

The 1^st electron shell (containing s subshell) can hold up to a maximum of 2 electrons. So draw the 1^st electron shell as follows:

In the above image, 1 represents the 1^st electron shell that contains 1s subshell. And the green color represents the number of electrons in that subshell. This means that the 1^st electron shell has a total of 2 electrons.

Since we have already used 2 electrons in the 1^st electron shell, now we have 85 – 2 = 83 electrons left. So in the next step, we have to draw the 2^nd electron shell.

Draw 2^nd electron shell

The 2^nd electron shell (containing s subshell and p subshell) can hold up to a maximum of 8 electrons. So draw the 2^nd electron shell as follows:

In the above image, 2 represents the 2^nd electron shell that contains 2s and 2p subshells. And the green and orange color represents the number of electrons in that subshell. This means that the 2^nd electron shell has a total of 8 electrons.

Now we have already used 10 electrons in 1^st and 2^nd electron shells, so we have 85 – 10 = 75 electrons left. So in the next step, we have to draw the 3^rd electron shell.

Draw 3^rd electron shell

The 3^rd electron shell (containing s subshell, p subshell, and d subshell) can hold up to a maximum of 18 electrons. So draw the 3^rd electron shell as follows:

In the above image, 3 represents the 3^rd electron shell that contains 3s, 3p, and 3d subshells. And the green, orange, and pink color represents the number of electrons in that subshell. This means that the 3^rd electron shell has a total of 18 electrons.

Now we have already used 28 electrons in 1^st, 2^nd, and 3^rd electron shells, so we have 85 – 28 = 57 electrons left. So in the next step, we have to draw the 4^th electron shell.

Draw 4^th electron shell

The 4^th electron shell (containing s subshell, p subshell, d subshell, and f subshell) can hold up to a maximum of 32 electrons. So draw the 4^th electron shell as follows:

In the above image, 4 represents the 4^th electron shell that contains 4s, 4p, 4d, and 4f subshells. And the green, orange, pink, and blue color represents the number of electrons in that subshell. This means that the 4^th electron shell has a total of 32 electrons.

Now we have already used 60 electrons in 1^st, 2^nd, 3^rd, and 4^th electron shells, so we have 85 – 60 = 25 electrons left. So in the next step, we have to draw the 5^th electron shell.

Draw 5^th electron shell

The 5^th electron shell can hold up to a maximum of 50 electrons. So draw the 5^th electron shell as follows:

In the above image, 5 represents the 5^th electron shell that contains 5s, 5p, and 5d subshells. And the green, orange, and pink color represents the number of electrons in that subshell. This means that the 5^th electron shell has a total of 18 electrons.

The 5^th electron shell contains only 5s, 5p, and 5d subshells, and not a 5f subshell. This is because according to the aufbau principle, the 6s subshell is filled first and then 4f, 5d, 6p… and so on.

Now we have already used 78 electrons in 1^st, 2^nd, 3^rd, 4^th, and 5^th electron shells, so we have 85 – 78 = 7 electrons left. So in the next step, we have to draw the 6^th electron shell.

Draw 6^th electron shell

The 6^th electron shell can hold up to a maximum of 72 electrons. So draw the 6^th electron shell as follows:

In the above image, 6 represents the 6^th electron shell that contains 6s and 6p subshells. And the green and orange color represents the number of electrons in that subshell. This means that the 6^th electron shell has a total of 7 electrons.

That’s it! This is the final Bohr model of astatine atom as we have used all 85 electrons: 2 electrons in the 1^st electron shell, 8 electrons in the 2^nd electron shell, 18 electrons in the 3^rd electron shell, 32 electrons in the 4^th electron shell, 18 electrons in the 5^th electron shell, and 7 electrons in the 6^th electron shell.

Next: Radon Bohr model

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Related

• Astatine

More topics

• Astatine valence electrons

External links

• File:85 astatine (At) enhanced Bohr model.png – Wikimedia Commons
• Chemical Elements.com – Astatine (At) – Chemical Elements.com
• What is the Bohr model for Astatine? – Topblogtenz
• Astatine (At) – Periodic Table – ChemicalAid