Concepts of Atomic Structure and Bonding

Introduction

The purpose of this essay is to discuss Atomic Structure and Bonding. The essay will explain the concepts of “mass number” and “relative atomic mass”, nucleon numbers, demonstrating how to deduce the electronic structure, explaining what ions are, and explaining what ionic bonds are. The research was conducted independently via online articles in order to show an understanding of Atomic Structure and Bonding.

The basic structure of an atom

Atoms consist of protons, electrons and neutrons. The nucleus is positioned in the centre of the atom and it contains the protons and the neutrons. The outer sections of the atom are called electron shells, and these are where the electrons are contained.

I have taken this image from (Lumen Learning, 2018) and it demonstrates the basic structure of an atom. (see description of the basic structure of an atom above this image)

How to identify a sample

Once I was given the atomic number for each of the samples, it was easy for me to identify what the samples were. I looked at the periodic table of elements and I was able to match the atomic number to the element.

Mass number and Relative Atomic Mass

Quite simply, mass number is the total number of protons and neutrons in a nucleus. On the other hand, relative atomic mass is a measure of how heavy atoms are. It is the ratio of the average mass of one atom of an element to one twelfth of the mass of an atom of carbon-12.

The main difference between the two is that relative atomic mass is the weighted average mass of an atom and mass number is a count of the total number of protons and neutrons in an atom’s nucleus. (Thoughtco, 2018)

Nucleon number

The nucleon number is quite simply, the total number of protons and neutrons in an atom’s nucleus. This number is different for each different isotope of a chemical element.

When finding out the nucleon number I used the following equation:

(Nucleon number = number of protons + number of neutrons)

I began by looking on the periodic table to find the elements that matched the listed atomic numbers. Secondly, I found out the numbers of protons and neutrons in each element. Lastly, to find out the nucleon number, I added the protons and neutrons together. (Socratic, 2017)

Please see (Appendix 1) below which is a table I have created to demonstrate the nucleon number of each listed element.

Appendix 1: A table showing the atomic number, chemical element, number of protons, number of neutrons and the nucleon number.

Fluorine

The 1s orbital can only hold two electrons so the first two will go in the 1s orbital. The next two electrons will go in the 2s orbital. Therefore, the remaining five electrons will go in the 2p orbital.

The electron configuration for Fluorine can be written as 1s22s22p5.

Krypton

There is space in the first shell for 2 electrons because it only has one subshell. The second shell has two subshells where S can have up to 2 electrons and P can have up to 6 electrons. This is also the case for the third subshell. The electron configuration for Krypton is [Ar] 3d¹⁰ 4s² 4p⁶.

Silver

The electron configuration for silver is based upon the place meant of silver in the fifth row of the periodic table in the 11th column. The electron configuration for silver is 1s22s22p63s23p64s23d104p65s14d10. This can be simplified as [Kr] 5s14d10.

Barium

For barium, we have 56 electrons. We start with the S block which holds up to two electrons. We then move onto the D block which holds up to ten electrons. Then, we finally move to the P block which holds up to six electrons. We repeat this until we have used up all 56 electrons. The electronic configuration for Barium is 1s22s22p63s23p64s23d104p65s24d105p66s2.

Deducing electron structures

Magnesium

• 1st shell can hold a maximum of 2
• 2nd shell can hold a maximum of 8
• 3rd shell can hold a maximum of 2

Therefore, the deduced electron arrangement for Magnesium will be written as 2,8,2.

Molybdenum

• 1st shell can hold a maximum of 2
• 2nd shell can hold a maximum of 8
• 3rd shell can hold a maximum of 18
• 4th shell can hold a maximum of 13
• 5th shell can hold a maximum of 1

Therefore, the deduced electron arrangement for Molybdenum will be written as 2,8,18,13,1.

Zinc

• 1st shell can hold a maximum of 2
• 2nd shell can hold a maximum of 8
• 3rd shell can hold a maximum of 18
• 4th shell can hold a maximum of 2

Therefore, the deduced electron arrangement for Zinc will be written as 2,8,18,2.

Krypton

• 1st shell can hold a maximum of 2
• 2nd shell can hold a maximum of 8
• 3rd shell can hold a maximum of 18
• 4th shell can hold a maximum of 8

Therefore, the deduced electron arrangement for Zinc will be written as 2,8,18,8.

Silicon

• 1st shell can hold a maximum of 2
• 2nd can hold a maximum of 8
• 3rd can also hold 2

Therefore, the deduced electron arrangement for Silicon will be written as 2,8,4. (Tutormyself, 2018)

Conclusion

To conclude, the number of negatively charged electrons dispersed outside the nucleus is the same as the number of positively charged in the nucleus. It explains the overall electrical neutrality of an atom. Most of the volume of an atom is empty space, and most of the atoms mass are confined in a small core called the nucleus.

Recommendations

I enjoy reading study materials and I find articles really useful. I aim to use books and physical study guides in future, but my reliance on online encyclopaedias has slightly reduced this time around.

If I had used a back-to-basics approach, there may have been a greater understanding present initially rather than wasting important time set aside for writing the essay.

Reference List

• Lumen Learning (2018) The basic structure of an Atom - Available at https://courses.lumenlearning.com/boundless-chemistry/chapter/the-structure-of-the-atom/  (Accessed: 4th March 2020).
• Socratic (2017) Nucleon number – Available at https://socratic.org/questions/what-is-the-nucleon-number (Accessed 5th March 2020)
• Thoughtco (2018) Mass number and relative atomic mass -  Available at https://www.thoughtco.com/atomic-mass-and-mass-number-606105 (Accessed 4th March 2020).
• Tutormyself (2018) Deducing electronic structure – Available at https://www.tutormyself.com/edexcel-igcse-2017chem-119/ (Accessed 5th March 2020)

Bibliography

• Lumen Learning (2018) The basic structure of an Atom - Available at https://courses.lumenlearning.com/boundless-chemistry/chapter/the-structure-of-the-atom/  (Accessed: 4th March 2020).
• Socratic (2017) Nucleon number – Available at https://socratic.org/questions/what-is-the-nucleon-number (Accessed 5th March 2020)
• Thoughtco (2018) Mass number and relative atomic mass -  Available at https://www.thoughtco.com/atomic-mass-and-mass-number-606105 (Accessed 4th March 2020).
• Tutormyself (2018) Deducing electronic structure – Available at https://www.tutormyself.com/edexcel-igcse-2017chem-119/ (Accessed 5th March 2020)

Appendices

• Appendix 1: Lumen Learning (2018) The basic structure of an Atom - Available at https://courses.lumenlearning.com/boundless-chemistry/chapter/the-structure-of-the-atom/  (Accessed: 4th March 2020).