Stage 3 Flashcards
Neutron
Neutral subatomic particle int he nucleus of an atom.
Proton
Positively charged subatomic particle inside the nucleus of an atom.
Electron
Negatively charged subatomic particle that is floating around the nucleus in the electron cloud. It is the smallest type of subatomic particles and they are part of chemical reactions.
Atomic number
Number of protons (or electrons Ina neutral atom) in an atom.
Atomic mass
The average of the weights of all the natural occurring isotopes of an element.
Mass number
Sum of the protons and neutrons in an atom’s nucleus.
Electron configuration
Shows the arrangements of e- in an atom
Atomic theories
Democritus, dalton, Thomson, Rutherford, Bohr, Schrödinger.
Atoms
Basic unit of all matter that contains the properties of an element.
Radioactivity
Release of energy by the atoms. Propriety.
Types of radiation
Alpha, beta and gamma
Example of radioactive elements
Plutonium (239), cobalt (60) and strontium (90)
S block
Groups 1A & 2A ink using including hydrogen and helium.
P block
3A - 8A! Excluding helium.
D block
Transition metals
F block
Inner transition metals (lanthanides and actinides)
Groups or families
Columns
Periods
Rows
Ionization energy periodic trend
It increases as you go up in a family and right in a period.
Electronegativity periodic trend
It increases as you go up in a family and right in a period.
Element with the highest electronegativity
Fluorine
Elements that have a high ionization energy but no electronegativity
Noble gases
Periodic trend in atom in radius
It increases as you go down in a family and left in a period.
Greek philosophers thought that matter …
Was made from four elects (air, water, fire and earth) and could be endlessly divided.
Democritus
Matter is made from tiny individual particle that cannot be created destroyer nor divided.
Main contributions of John Dalton
He was the first one to sustain the fact that everything is made out of worms, he said that atoms of difference elements had different weights, that everything was made up of atoms and that toms were the smallest indivisible particle.
Principle of Dalton’s model
- Everything is made out of atoms. They are indivisible and indestructible.
- Atoms cannot be created nor destroyed.
- atoms of the same element have the same size, chemical properties and mass. They are different from atoms of other elements.
- Atoms of different elements combine to form compounds.
Dalton was wrong because …
He didn’t include the subatomic particles and because isotopes of the same element have different masses.
Laws used by dalton
Law of conservation of mass
Law of constant competition/ definite properties
Law of multiple proportions
Law of conservation of mass
Mass cannot be created nor destroyed, only transformed
Thomson’s model
Plum pudding model
Main contribution of Thomson
Addition of electrons to the atomic model.
Thomson’s experiment
Used a cathode-ray tube (electron gun) to create negative ways made from negative particles that were deflected by a positive wave between magnets.
Description of Thomson’s model
Negative charged particles (plums) swimming in a sea of positive charge (pudding)
Thomson was wrong because …
He didn’t mention the nucleus.
Rutherford’s main contribution
The inclusion of the positively charged nucleus by a bunch of negatively charges particles.
Rutherford’s experiment
Gold foil experiment. He fire we alpha particles at a foil expecting them to be rejected.
Description of Rutherford’s model
Positively charge nucleus in which most of the atom’s mass is located surrounded by circulating electrons.
Rutherford’s model
Nuclear atom
Rutherford was wrong because …
His model did not explain the electron arrangement and in this model the electrons would eventually collide with the nucleus.
Bohr’s model
Solar system model
Bohr’s main contribution
Implementation of electron orbits (shells [energy levels] and levels)
Bohr was wrong because …
Its model could not be used for atoms more complicated than hydrogen.
Photon
Massless particle that contains quantum energy and that is real eased when an electron passes from its exited state into its ground state.
Ground states
The lowest allowable energy state
Exited state
When an atom gains energy
When does scent so observed that elements have of visible light
When heated by flame
Schrödinger’s model
Quantum mechanical model
Main contribution Schrödinger
Inclusion of electron orbitals.
Characteristic of the quantum mechanical model
It can help us calculate the probability of finding an electron in a particular volume of space close to the nucleus.
Atomic orbital
Region around a nucleus in which it is described an elctron’s probable location in the electron clouds.
Heisenberg uncertainty principle
It is impossible to know the location and velocity of a particle at the same time. So you can only know the probability of an electron to occupy a certain region around the nucleus.
Proton charge
+1
Proton symbol
P+
Proton discover
Rutherford in 1919 with the gold foil experiment.
Neutron charge
0
Neutron symbol
n0
Neutron discovery
Chadwick in 1932 while examinating penetrating radiation
Electron change
-1
Electron symbol
e-
Electron discovery
Thomson in 1897 wile testing and measuring the cathode Rays.
Isotope
Atoms with the same number of protons but different number of neutrons.
Isotopic notation
A
X
Z
A
Mass number (p+ + n0)
Z
Atomic number
of p+ (atomic number)
Z
X
Symbol of the element
Energy level
Possible orbits in which the elctrons may be found
Sublevels
Divisions of the energy levels into s, p, d, f,
Orbitals
Spaces that have a high probability of continuing an electron.
Sublevels s
1 orbital 2e
Sublevels p
Orbital 3 6 e
D subshell
5 orbitals and 10 e
F sushell
7 orbitals and 14 e-
Electron configuration
the arrangement of electrons in an atom.
Orbital diagram
Diagram that shows how the orbit in a subshell are occupied by electrons.
Abbreviated notation
Noble has notation
Diagonal rule
1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d 7p
Quantum number
Their combination tells the location of an specific electron
Type of quantum numbers
- N, l, m, x
N
Principal level
L
Angular sublevels
M
Magnetism orbitals
S
Spin 1/2 or -1/2
Gold rule
No two e- will have the same 4 quantum numbers.
Aufbau principle
Each electron occupies the lowest energy orbitals available.
Hund’s rule
Single electrons with the same spin must occupy equal orbital before additional electrons with apposite spins occupy.
Name of each family
Alkali metals Alkaline earth metals Boron family Carbon family Nitrogen family Oxygen party or chalcogens Halogens Noble gases.
Oxidation number for each family
+1, +2, +3, +4 or -4, -3, -2, -1.
Octet rule
Atoms will gain, lose or share electrons to acquire a full set of eighth valence electrons.
Electronegativity
Ability of an element to attract electrons in a chemical bond.
Atomic radius
Distance between the valence electrons and the nucleus.
Ionization energy
Energy require to remove an electron from an atom.
Valence electrons
They are the electrons in the outermost energy level, hey determine the charactestics of a compound and they also made a shame of them selves
