The Atom Flashcards
The indivisible particles Leucippus and Democritus said would be the result of dividing matter again and again
atoms
The model John Dalton adopted (also by Leucippus and Democritus)
spherical model
Who made the plum pudding model and said that atoms are actually divisible (with electrons in a sea of positive charge)?
JJ Thomson
Who did the alpha scattering experiment on thin gold foil (showing positive alpha particles passed through most of the atom)?
Ernest Rutherford
The atom is mostly open/closed space
Open
Atoms of different elements have ____ positive charges
different
Who discovered protons?
Eugen Goldstein
Who discovered neutrons?
James Chadwick
Who developed the Planetary model (showing electrons orbiting in specific energy levels)?
Niels Bohr
What model did Ernest Rutherford develop?
Nuclear Model
Who said particles such as electrons exhibit wave like behavior?
Louie de Broglie
Who revised Bohr’s model?
Erwin Schrödinger
What did Werner Heisenberg say about modeling electrons?
It is mathematically impossible to know the position and momentum of an electron at a specific time
The region electrons are most likely to be found
atomic orbitals
What is in John Dalton’s theory?
- Elements are composed of small particles called atoms
- Law of Conservation of Mass (total mass of reactants = total mass of products)
- Law of Definite Proportion or Composition
- Law of Multiple Proportions
What does the law of definite proportion mean?
H2O = 1 hydrogen for every 2 oxygen and vice versa
What does the law of Multiple proportions mean?
atoms can combine or separate to make variations of a product in different proportions (carbon and oxygen can make CO2 or CO)
What are the nucleons (found in nucleus)?
protons and neutrons
Who discovered the photoelectric effect?
Heinrich Hertz
What did Albert Einstein theorize for light?
Existence of packets of light now called photons
Who proposed that the momentum (frequency) is inversely proportional to the wavelength?
Louie de Broglie
What does the principal quantum number represent?
shell or energy level
What does the Azimuthal quantum number represent?
electron subshell
What does the magnetic quantum number represent?
orbital
What does the spin magnetic quantum number represent?
magnetic spin
No two electrons can have the same set of quantum numbers
Pauli’s Exclusion Principle
Electrons occupy singly before pairing up
Hund’s Rule of Maximum Multiplicity
Electrons occupy the lowest available energy levels before filling higher levels
Aufbau Principle
Who devised the Modern Periodic Table of Elements?
Dmitri Mendeleev
Materials that have properties in between metals and non metals
Metalloids
what is electronegativity?
ability to attract an electron
what is ionization energy?
energy needed to remove an electron
what is electron affinity?
energy released when a gaseous atom gains an electron
what are ions?
atoms that have lost or gained electrons (changing its charge)
positively atoms are smaller than neutral atoms, true or false?
true
why are anions larger than the neutral atom?
because there are more electrons in the cloud
