M2-L1: Early Concepts About the Atom Flashcards
All matter is composed of minute, sub microscopic, indivisible particles called _____.
Atoms
The earliest model of the atom was developed by the ancient _____ philosophers and Scientists in the past.
Greek
The discoveries of the modern scientist disproved ______’s theory.
John Dalton
There are many kinds of atoms as there are kinds of elements, which are chemically _________ from each other.
Different
Isotopes are atoms of the same element having different ______ ____.
Atomic Mass
An ____ is composed of a tiny core or nucleus with electrons outside the nucleus.
Atom
An atom is composed of a tiny core or _______ with electrons outside the nucleus.
Nucleus
An atom is composed of a tiny core or nucleus with _________ outside the nucleus.
Electrons
The nucleus contains protons but no ________.
Electrons
The negative charge on the electrons balances the positive charge on the nucleus so that an atom is electrically ______.
Neutral
At least 99.9% of the mass of an atom is in the _______.
Nucleus
The electrons are at relatively large distances from the _______.
Nucleus
An atom is mostly empty _____.
Space
The small, dense center of positive charge in the atoms.
Nucleus
Uncharged particle.
Neutron
The sum of masses of proton and neutron.
Atomic Mass
Element with the same atomic number but different atomic mass.
Isotopes
Sublevel s has how many maximum number of electrons?
2
Sublevel p has how many maximum number of electrons?
6
Sublevel d has how many maximum number of electrons?
10
Sublevel f has how many maximum number of electrons?
14
Each orbitals have a maximum of ___ electrons.
Two
Modifications of the Bohr’s theory led to the theory of atomic structure which is based on _______ mechanics or wave mechanics.
Quantum
This theory shows that electrons tend to occupy various energy levels designated as K,L,M,N,O etc. or 1,2,3,4, etc.
Schrodinger’s Wave Mechanical Model of the Atom
Shells 1, 2, 3, and 4 corresponds to what shell letters?
1 = K
2 = L
3 = M
4 = N
Shell K or 1 has _ maximum number of electrons.
2
Shell L or 2 has _ maximum number of electrons.
8
Shell M or 3 has _ maximum number of electrons.
18
Shell N or 4 has _ maximum number of electrons.
32
Proposed a model of the atom in terms of waves.
Quantum Theory or Waves Theory (Erwin Schrodinger)
Paved the way for the development of the wave mechanics.
Heisenberg’s Theory
This theory states that the exact position and exact location of the electron cannot be pinpointed.
Heisenberg’s Theory
In the wave mechanical model, the electron can be determined only in terms of _______.
Orbital
The energy state of the electron in an atom can be described by a set of numbers called the quantum numbers _, _, _, _,.
n, l, m, s
Set the probability within which an electron can be found.
Four quantum numbers
Describes the relative position of these energy level, their distance from nucleus and the energy of an electron.
Principal quantum number (n)
Principal Quantum numbers are represented by numbers 1,2,3,4 . . . or letters _, _, _, _.
K, L, M, N
Describes the shape of the orbital on the electron cloud.
Azimuthal/Subsidiary/Orbital quantum number
AQN (l): Is represented by what letters?
s, p, d, f
AQN (l): The value of s is?
0
AQN (l): The value of p is?
1
AQN (l): The value of d is?
2
AQN (l): The value of f is?
3
Describes the spatial orientation of the orbitals.
Magnetic quantum number
It is dependent on the values of azimuthal quantum number.
Magnetic quantum number
This number describes the direction the electron is spinning in a magnetic field — either clockwise or counterclockwise.
Spin quantum number
The first person to come up with an idea of an atom.
Democritus
He used the word “atomos”, which is a Greek word for uncuttable or smallest indivisible and indestructible particle.
Democritus
He did not believe that matter is made up of tiny particles called atoms.
Aristotle
He believed that matter is made out of five elements: earth, water, air, fire, and aether.
Aristotle
He studies how gases combine, react, and move with temperature and pressure.
John Dalton
He developed his idea called the “atomic theory.”
John Dalton
He discovered that atoms could be divided, and discovered the negatively charged particle called the “electron.”
JJ Thompson
He called his theory the “plum pudding model.”
JJ Thompson
He is responsible for the discovery of protons.
William Goldstein
He fired alpha particles at a very thin sheet of gold foil.
Ernest Rutherford
He discovered that the atom contained a dense center which was positively charged/had the proton.
Ernest Rutherford
He discovered that the atom was made up of mostly empty space.
Ernest Rutherford
His model is called the “Bohr Model of the Atom.”
Niels Bohr
He found that electrons will actually travel around the atom in discrete energy levels; that electrons can never exist between energy levels.
Niels Bohr
He also found that electrons can move up an energy level if they are given enough energy.
Niels Bohr
He called this amount of energy as a “quantum of energy.”
Niels Bohr
He proposed that waves can act like particles, and particles can act like waves.
Louis De Broglie
He suggested that electrons can better be described as waves rather than as particles.
Louis De Broglie
He proposed that one of the implication of electrons behaving like waves is that you cannot know both the speed and position of an electron at the same time.
Werner Heisenberg
He developed a mathematical equation to show where the electrons are located around the nucleus.
Erwin Schrodinger
He showed us that with his wave equation that we can only know regions of probability of finding an electron, which is called the “electron cloud model.”
Erwin Schrodinger
Erwin Schrodinger showed us that with his wave equation that we can only know regions of probability of finding an electron, which is called the “________ _____ _____.”
Electron Cloud Model
He was responsible for the discovery of the neutron.
James Chadwick
Identical to electron but with a positive charge.
Position
Uncharged species of zero mass.
Neutrino
An electron unstable particle omitted from the nucleus.
Betatron
Principle: Electrons tend to occupy a lower orbital surface going to a higher energy orbital.
Aufbau Principle or Building up principle
Principle: The maximum number of electrons in an orbital is two and they must be of opposite spin.
Paulis Exclusion Principle
When a number of degenerate orbitals are available and there is no electron to fill up, all other orbitals to full capacity of two electrons, each member of the degenerate set receives one electron, before anyone of the set receives two electrons.
Hund’s Rule
