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Electron orbitals

Although useful to explain the reactivity and chemical bonding of certain elements, the Bohr model of the atom does not accurately reflect how electrons are spatially distributed surrounding the nucleus. They do not circle the nucleus like the earth orbits the sun, but are found in electron orbitals . These relatively complex shapes result from the fact that electrons behave not just like particles, but also like waves. Mathematical equations from quantum mechanics known as wave functions can predict within a certain level of probability where an electron might be at any given time. The area where an electron is most likely to be found is called its orbital.

Recall that the Bohr model depicts an atom’s electron shell configuration. Within each electron shell are subshells, and each subshell has a specified number of orbitals containing electrons. While it is impossible to calculate exactly where an electron is located, scientists know that it is most probably located within its orbital path. Subshells are designated by the letter s, p , d , and f . The s subshell is spherical in shape and has one orbital. Principal shell 1n has only a single s orbital, which can hold two electrons. Principal shell 2n has one s and one p subshell, and can hold a total of eight electrons. The p subshell has three dumbbell-shaped orbitals, as illustrated in [link] . Subshells d and f have more complex shapes and contain five and seven orbitals, respectively. These are not shown in the illustration. Principal shell 3n has s , p , and d subshells and can hold 18 electrons. Principal shell 4n has s , p , d and f orbitals and can hold 32 electrons. Moving away from the nucleus, the number of electrons and orbitals found in the energy levels increases. Progressing from one atom to the next in the periodic table, the electron structure can be worked out by fitting an extra electron into the next available orbital.

Illustration shows 1ns, 2ns and 2np subshells. The 1ns subshell and 2ns subshells are both spheres, but the 2ns sphere is larger than the 1ns sphere. The 2np subshell is made up of three dumbbells that radiate out from the center of the atom.
The s subshells are shaped like spheres. Both the 1n and 2n principal shells have an s orbital, but the size of the sphere is larger in the 2n orbital. Each sphere is a single orbital. p subshells are made up of three dumbbell-shaped orbitals. Principal shell 2n has a p subshell, but shell 1 does not.

The closest orbital to the nucleus, called the 1s orbital, can hold up to two electrons. This orbital is equivalent to the innermost electron shell of the Bohr model of the atom. It is called the 1 s orbital because it is spherical around the nucleus. The 1 s orbital is the closest orbital to the nucleus, and it is always filled first, before any other orbital can be filled. Hydrogen has one electron; therefore, it has only one spot within the 1 s orbital occupied. This is designated as 1 s 1 , where the superscripted 1 refers to the one electron within the 1 s orbital. Helium has two electrons; therefore, it can completely fill the 1 s orbital with its two electrons. This is designated as 1 s 2 , referring to the two electrons of helium in the 1 s orbital. On the periodic table [link] , hydrogen and helium are the only two elements in the first row (period); this is because they only have electrons in their first shell, the 1 s orbital. Hydrogen and helium are the only two elements that have the 1 s and no other electron orbitals in the electrically neutral state.

Questions & Answers

what is nutrition
Joseph Reply
the process of providing or obtaining the food necessary for health and growth.
fatimah
what are micro-organism
Bukiwe Reply
what is immunity
Moriba Reply
What is cross pollination
Moriba
what is pollution
Georgiana Reply
what is pollution
Georgiana
list four type of biological association
Georgiana
Pollution is the release of harmful substances in the atmosphere.
Immanuel
Four biological associations are 1) commensalism 2)symbiosis 3)mutualism 4) parasitism
Immanuel
What is the function of the hormones
Immanuel Reply
What is the other name of filament of a flower
Immanuel
oxygen
Georgiana
list three bone disorders and explain them
Blessings Reply
oxygen
Georgiana
what is self pollination?
Kelvin Reply
well, self-pollination occurs in a single flower which has the organs of both genders. the pollen grains from the anther shall be captured by the stigma of the flower, when released. and the pollen grain shall start grow pollen tube which grows down in the style, to the ovary, ovules and the
Izzati
insides of the ovules. so pretty much the pollen grains being pollinated from the anther to the stigma of the same flower
Izzati
I think
Izzati
the pollen grains being pollinated from the anther to the stigma of the same flower
Izzati
what is animal science
Rose Reply
Animal science is described as "studying the biology of animals that are under the control of humankind".
AMIIRA
don't you guys have Google
Izzati
what is self pollinating
JOSHUA Reply
what is cleistogamy
JOSHUA
Self pollination occurs when the pollen from the anther is deposited on the stigma of the same flower, or another flower on the same plant.
Franklina
Cleistogamy is a type of automatic self pollination of certain plants that can propagate by using non opening, self pollinating flowers
Franklina
Self pollination is the transfer of pollen grain from the anther to the stigma
Immanuel
who is the father of biology
Sean Reply
Aristotle
Lubera
Aristotle
estella
yes Aristotle looking at classification
John
Aristotle
JOSHUA
Aristotle
Grace
please my answer
Sean
Aristotle
Rose
Aristotle
Immanuel
what are prokaryotic cells
Kusubira Reply
having cell that lack membrane - bound nuclei.
Lubera
Pronkayotic cells are cells that lacks nuclear membrane
Immanuel
Please each person should suggest ur answers
Franklina Reply
differentiate between autelogical and synecology
Christiana Reply
differentiate between autelogical and synecology
Christiana Reply
answer please
Edmond
Autecology is the study of individual organism or individual species. It is also known as population ecology. Synecology is the study of group of organisms of different species which are associated together as a unit in form of a community.
Daniel
Autecology is the study of the environment in relation to only one species in contrast while synecology is the study of the environment affecting groups of species coexisting in an area.
Franklina
Describe the factors affecting homotasis
Grace Reply
Fluids and electrolytes Energy and nutrition Immune response mediators
Franklina

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Source:  OpenStax, Biology. OpenStax CNX. Feb 29, 2016 Download for free at http://cnx.org/content/col11448/1.10
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