Can lithium have 3 neutrons?
In a chunk of lithium, 93% will always be lithium with 4 neutrons, while the remaining 7% will always be lithium with 3 neutrons.
This means that a lithium atom with three protons and three neutrons would be listed as lithium-6.
b. Notice that because the lithium atom always has 3 protons, the atomic number for lithium is always 3. The mass number, however, is 6 in the isotope with 3 neutrons, and 7 in the isotope with 4 neutrons.
The sum of the number of neutrons and protons in an atom of the element is called a mass number of an atom. Lithium contains 3 electrons, 4 neutrons, and 3 protons. Mass number (A) = Number of Proton + Number of Neutron. Mass number (A) = 3 + 4 = 7.
Nuclei of lithium can have 3, 4 or 5 neutrons. We call these different isotopes of lithium. Since different isotopes of an element have different numbers of neutrons (but always the same number of protons) they have different mass numbers.
Finding the Number of Neutrons
The number of neutrons in an atom can be calculated by subtracting the atomic number from the atomic mass. Both of these numbers can be found on the periodic table. The atomic number is listed above the symbol of the element whereas the mass number is placed below.
Carbon occurs naturally in three isotopes: carbon 12, which has 6 neutrons (plus 6 protons equals 12), carbon 13, which has 7 neutrons, and carbon 14, which has 8 neutrons. Every element has its own number of isotopes.
If you have 3 protons in the nucleus, it is lithium, no matter what else you may or may not have. The isotope number, 7 in this case, indicates the total number of protons and neutrons in the nucleus. So lithium-7 has 3 protons (because it's lithium) and 4 neutrons (7–3=4).
In the lithium atom the two electrons in the 1s orbital are paired, and the electron in the 2s orbital is unpaired.
A lithium atom contains 3 protons in its nucleus irrespective of the number of neutrons or electrons. Notice that because the lithium atom always has 3 protons, the atomic number for lithium is always 3. The mass number, however, is 6 in the isotope with 3 neutrons, and 7 in the isotope with 4 neutrons.
Why does lithium only have 3 electrons?
Lithium is the 3rd element on the periodic table because it has 3 protons in its nucleus. Lithium therefore has three electrons. The first two occupy an inner core shell, which is the 1s2 di-electron, just like helium's.
References
- https://www.toppr.com/ask/question/how-many-shells-are-present-in-all-the-elements-that-belong-to-period-3/
- https://chem.libretexts.org/Courses/University_of_British_Columbia/CHEM_100%3A_Foundations_of_Chemistry/04%3A_Atoms_and_Elements/4.5%3A_Elements%3A_Defined_by_Their_Number_of_Protons
- https://www.angelo.edu/faculty/kboudrea/periodic/periodic_main3.htm
- https://www.physicsclassroom.com/Concept-Builders/Chemistry/Ionic-Bonding/conceptBuilderHelp/help6
- https://chem.libretexts.org/Bookshelves/Inorganic_Chemistry/Supplemental_Modules_and_Websites_(Inorganic_Chemistry)/Descriptive_Chemistry/Elements_Organized_by_Block/2_p-Block_Elements/Group_13%3A_The_Boron_Family/Z013_Chemistry_of_Aluminum_(Z13)
- https://chem.libretexts.org/Bookshelves/Introductory_Chemistry/Introductory_Chemistry/04%3A_Atoms_and_Elements/4.08%3A_Isotopes_-_When_the_Number_of_Neutrons_Varies
- https://www.thoughtco.com/atomic-number-4-element-facts-606484
- https://testbook.com/question-answer/which-element-has-three-shells-which-are-completel--60090d9228da4995ec0bf184
- https://en.wikipedia.org/wiki/Tertiary_carbon
- https://www.rsc.org/periodic-table/element/21/scandium
- https://www.biology-pages.info/E/Elements.html
- https://www.aps.org/publications/apsnews/201904/history.cfm
- https://byjus.com/question-answer/although-both-co-2-and-h-2o-are-triatomic-molecules-the-shape-of-h-2o/
- https://www.weforum.org/agenda/2021/12/abundance-elements-earth-crust/
- https://www.nrc.gov/reading-rm/basic-ref/students/science-101/what-is-an-atom.html
- https://www.amnh.org/explore/ology/physics/atomic-mobile2
- https://www.britannica.com/science/baryon
- https://www.britannica.com/science/triple-bond
- https://byjus.com/question-answer/give-two-examples-of-a-triatomic-molecule/
- https://www.collinsdictionary.com/us/dictionary/english/trio
- https://www.angelo.edu/faculty/kboudrea/periodic/structure_numbers.htm
- https://www.symmetrymagazine.org/article/what-is-a-particle
- https://en.wikipedia.org/wiki/Group_3_element
- https://www.thoughtco.com/atomic-number-3-element-facts-606483
- https://home.miracosta.edu/dlr/naming.htm
- https://pubchem.ncbi.nlm.nih.gov/element/Lithium
- https://uen.pressbooks.pub/introductorychemistry/chapter/the-structure-of-the-atom/
- https://www.newscientist.com/article/dn21927-triple-bonded-boron-opens-new-chemical-world/
- https://chem.libretexts.org/Courses/University_of_South_Carolina__Upstate/USC_Upstate%3A_CHEM_U109_-_Chemistry_of_Living_Things_(Mueller)/02%3A_Elements%2C_Atoms%2C_and_the_Periodic_Table/2.6%3A_Arrangements_of_Electrons
- https://www.cuemath.com/numbers/iii-roman-numerals/
- http://butane.chem.uiuc.edu/cyerkes/chem102ae_fa08/homepage/chem102aefa07/Lecture_Notes_102/102Lecture13.htm
- https://www.vedantu.com/question-answer/the-number-of-atoms-in-01-mol-triatomic-gas-is-class-11-chemistry-cbse-5f4829e0b558257ed509dc9f
- https://en.wikipedia.org/wiki/Delta_baryon
- https://en.wikipedia.org/wiki/Chemical_symbol
- https://www.techtarget.com/searchcio/definition/atom
- https://www.britannica.com/science/boron-chemical-element
- https://www.rsc.org/periodic-table/element/3/lithium
- https://en.wikipedia.org/wiki/Trisulfur
- https://byjus.com/chemistry/elements-and-compounds/
- https://chem.libretexts.org/Courses/Purdue/Purdue%3A_Chem_26505%3A_Organic_Chemistry_I_(Lipton)/Chapter_1._Electronic_Structure_and_Chemical_Bonding/1.03_Valence_electrons_and_open_valences
- https://chemed.chem.purdue.edu/genchem/topicreview/bp/ch8/
- https://byjus.com/question-answer/lithium-has-3-electrons-4-neutrons-and-3-protons-its-mass-number-is/
- https://chem.libretexts.org/Courses/Oregon_Tech_PortlandMetro_Campus/OT_-_PDX_-_Metro%3A_General_Chemistry_I/03%3A_Nuclei_Ions_and_the_Periodic_Table/3.03%3A_Predicting_Charges_of_Ions
- https://www.angelo.edu/faculty/kboudrea/molecule_gallery/01_alkanes/00_alkanes.htm
- https://byjus.com/question-answer/the-three-basic-components-of-an-atom-are-protons-neutrons-and-electronsprotons-neutrinos-and-ions-1/
- https://homework.study.com/explanation/how-many-valence-electrons-does-aluminum-have.html
- https://www.vedantu.com/question-answer/give-one-example-of-a-triatomic-molecule-class-11-chemistry-cbse-5fb364e3de1c3232ee2f126f
- https://en.wikipedia.org/wiki/Atom_(character)
- https://homework.study.com/explanation/name-an-element-in-the-third-period-row-of-the-periodic-table-with-three-valence-electrons.html
- https://www.numerade.com/ask/question/which-of-the-following-is-most-likely-to-make-a-3-ion-aai-b-p-be-d-se-e-bi-42237/
- https://chem.libretexts.org/Bookshelves/Inorganic_Chemistry/Supplemental_Modules_and_Websites_(Inorganic_Chemistry)/Descriptive_Chemistry/Elements_Organized_by_Block/1_s-Block_Elements/Group__1%3A_The_Alkali_Metals/Z003_Chemistry_of_Lithium_(Z3)
- https://en.wikipedia.org/wiki/Nitrate
- https://byjus.com/chemistry/atoms-and-molecules/
- https://www.toppr.com/ask/question/how-many-electrons-does-metal-have-in-the-valence-shell/
- https://homework.study.com/explanation/how-many-electrons-are-in-a-plus-3-cation-with-an-atomic-number-of-13.html
- https://www.lwtech.edu/campus-life/learning-lab/resources/docs/lwtech-learning-lab-science-atom-structure.pdf
- https://www.studocu.com/en-us/messages/question/2811388/how-do-atoms-share-more-than-one-pair-of-electrons
- https://chem.libretexts.org/Bookshelves/Inorganic_Chemistry/Supplemental_Modules_and_Websites_(Inorganic_Chemistry)/Chemical_Compounds/Nomenclature_of_Inorganic_Compounds
- https://byjus.com/question-answer/an-neutral-element-a-has-3-electrons-the-atomic-number-of-an-element-is-fill-in-the-blank/
- http://hobart.k12.in.us/ksms/PeriodicTable/energy%20levels.htm
- https://mccord.cm.utexas.edu/chembook/page-nonav.php?chnum=1§=2
- https://www.sciencedirect.com/topics/chemistry/covalent-bond