CHEMICAL BASES: ACTIVITY 1 "ATOMS AND MOLECULES" ( (Isotopes…
ACTIVITY 1 "ATOMS AND MOLECULES"
They are atoms that have the same atomic number and different atomic mass. Most elements have isotopes, but they are not very different from each other, since their properties are mainly determined by the number of protons and electrons.
Carbon has several different isotopes, one of them is Carbon-13. Carbon-13 has 6 protons and 7 neutrons, it also has an atomic mass of 13.
The atomic mass is the sum of the neutrons and protons present in an atom, with the exception of hydrogen, which has no neutrons, It can be represented by the letter "A".
Carbon has an atomic mass of 12. Since we already know it has 6 protons thanks to its atomic number, we now know that it also has 6 neutrons.
The atomic number is represented by a letter "Z" and it indicates the number of protons in the nucleus of an atom. If said atom happens to be neutral, the atomic number will also indicate the number of electrons.
The atomic number of Carbon is 6. A neutral atom of carbon will have 6 protons and subsequently 6 electrons.
Noble gas notation
Atom (or group of atoms) electrically charged
formed by the loss or gain of electrons.
A positive ion is called a "cation", which results when an atom loses an electron.
A negative ion is called an "anion", and results when an atom gains an electron.
The valence of an ion refers to the number of electrons lost or gained by the original atom. A plus sign represents cations, and a minus sign represents anions.
For example: Na+, Cl-, Ca 2+
María José Talamás
José Miguel Guizar
Substance formed by atoms of the same atomic number (their nucleus has the same number of protons, regardless of the number of neutrons).
The octet rule, created in 1916 by Gilbert N. Lewis, is the tendency of atoms to have 8 electrons in their valence shells. Atoms can either give electrons or recieve electrons depending on how many electrons are in the last level of the valence shell.
When applying the octet rule, you should not consider the d and f orbitals, instead, we focus on the s and p orbitals.
"Its the fundamental piece of matter and the defining structure of elements. In the universe everything, except energy, is made of atoms.
An atom is made up of 3 subparticles: Protons, neutrons and electrons. Protons and neutrons are together in the nucleus while the electrons orbit around the nucleus."
Every substance is made from atoms. An atom is made up from: A Nucleus witch contains Protons
(Neutrally Charged particles), and Protons (positive charged particles). Atoms are surrounded by Electrons (Negative charged particles) , this makes an equilibrium between charges. Protons and Electrons have
the same mass and electron mass is almost 0 (0.0005 ).
A molecule is when you get atoms together. Every compound is a molecule but not every molecule is a compound. A compound is what you get when you join two or more atoms of different elements.
Calbreath, B. (n.d). Hund’s Rule and Orbital Filling Diagrams. August 2017, Lumen, from
James, J. (2017). Review of Atomic Orbitals. August 2017, Master Organic Chemistry, from
McClure, M.W. (2012). Electron Configuration. August 2017, Hopkinsville Community College, from
N.d. (2014). Atomic structure. BBC. Retrieved August 14, 2017, from
N.d. (2015). Shapes of Atomic Orbitals. August 2017, Wikibooks, from
SparkNotes Editors. (n.d.). SparkNote on Atomic Structure. Retrieved August 11, 2017, from
Chang, R. (2010). QUÍMICA. DÉCIMA EDICIÓN. McGRAWW-HILL.
Questions and Answers. (n.d.). Retrieved August 14, 2017, from
Helmestine, A. . (2017). What is an atom?. August 14, 2017, de Thought Co. Sitio web:
T. S. (2017). What is an atom. Retrieved August 12, 2017, from
N. D. (2016). The Octet Rule. Retrieved August 12, 2017, from
Anónimo . (2017). Definición de elemento químico. Agosto 14, 2017, de Definición.de Sitio web:
Portal educativo . (2017). Los cuatro números cuánticos y su significado. 12/08/17, de Portal Educativo Sitio web:
Chemistry LibreTexts. (2016). Electronic Configurations Intro. [online] Available at:
[Accessed 15 Aug. 2017].
The American Heritage New Dictionary of Cultural Literacy. (2005). ION. August 2017, de Houghton Mifflin Company Sitio web:
Orbitals define an element's ionization energy
Regions of space around the nucleus a certain where an electron may be present.
DISTRIBUTION OF ORBITALS
CORRECT ORBITAL FILLING
Since electrons are negatively charged, and equal charges repel each other, when filling up the orbitals electrons will try to be as far away from each other as possible. This means then when filling an orbital of equal energy (e.g. p) they will fill up a different orbital first and then pair up.
ORBITALS: 7s 7p7p7p
TOTAL OF ELECTRONS: 8
ORBITALS: 6s 6p6p6p 6d6d6d6d6d
TOTAL OF ELECTRONS: 18
ORBITALS: 5s 5p5p5p 5d5d5d5d5d 5f5f5f5f5f5f5f
TOTAL OF ELECTRONS: 32
ORBITALS: 4s 4p4p4p 4d4d4d4d4d 4f4f4f4f4f4f4f
TOTAL OF ELECTRONS: 32
ORBITALS: 3s 3p3p3p 3d3d3d3d3d
TOTAL OF ELECTRONS: 18
ORBITALS: 2s 2p2p2p
TOTAL OF ELECTRONS: 8
TOTAL OF ELECTRONS: 2
SHAPES OF ORBITALS
Shaped like a sphere is the only type of orbitals that has only one possible orientation (m quantum number) therefore it can hold only 2 electrons
Shaped like a dumbell
Has 3 possible orientations (m=-1,0,1)
Can hold 6 electrons (2 per orientation)
Has 5 possible orientations (m=-2,-1,0,1,2)
Can hold 10 electrons (2 per orientation)
Has 7 possible orientations (m=-3,-2,-1,0,1,2,3)
Can hold 14 electrons (2 per orientation)
Heisenberg Uncertainty Principle:
"It is impossible to determine, at the same time, the exact momentum and position for an electron."
We can't establish with complete certainty what is the exact position and direction of an electron, but we can calculate its probability. However the higher the probability for an electron's position the lower it will be for its direction, and viceversa.
Electron spin quantum number (s)
The electron possesses its own quantum number that reveals the direction of rotation of the
electron around its axis when it moves into an orbital.
Principal quantum numbers (n)
Magnetic quantum numbers (m)
It indicates the orientation of the orbital.
p: m= -1,0,+1
d: m= -2,-1,0,+1,+2
f: m= -3,-2,-1,0,+1,+2,+3
Angular quantum numbers (l)
It describes the geometrical form of an orbital.
If the last level of an element is 3s, then l=0.
It specifies the level of energy in an orbital, and it relates with the average distance between the electron and nucleus
If the last level of an element is 3s, then n=3
Is the representation of the arrangement of electrons distributed among the orbital shells and subshells of an atom. There are 3 different ways of writing the electronic configuration of an element:
Shows each of the separate orbitals and the spins on the electrons.
Most common way to describe electron configurations. The total number of electrons in each energy level is described by a superscript thar follows the relating level.
Uses noble gases as reference. the noble gas in the period above the element that your using is used to denote te subshells that elemnt has filled and after which the valence electrons are written.