Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

30 Cards in this Set

  • Front
  • Back
the smallest unit of an element that can exist either alone or in combination with atoms of the same or different elements
physical structure
Chemical reaction
take the parts and bond them together, exchange of energy we make a unique bonding- ionic, covalent, enxchange of energy cause atoms to become linked together
Atomic theory, thought an atom was solid. Came up with the law of definite, and multiple proportions, and the law of conservation of mass.
Law of conservation of mass
mass is neither destroyed nor created, during ordinary chemical or physical reactions.
Law of definite proportions
Chemical reaction contains the same elements and exactly the same mass regardless the size of the sample or compound.
Law of multiple proportions
if two or more different compounds are composed of the same two elements then the ratio of the masses of the second element combined with a certain mass of the first element is always a ration of small whole numbers.
Very small region located near the center of an atom which contains at least one positively charged particle.
Electron Cloud
surronds nucleus
Negatively charged particle found in the nucleus.
Nuclear particle that has no electrical charge.
Positively charged particle found in the nucleus.
atomic number
number of protons in nucleus of each atom of an element.
atomic mass
the average mean value of the isotopic masses of the atom of an element.
mass number
total number of protons and neutrons in hte nucleus of an isotope.
atomic radius
1/2 the diameter of the atomic field.
nuclear force
short-rangeproton-neutron, proton-proton, or neutron-neutron force that holds the nuclear particles together.
atom mass units(amu)
1/2 mass of a carbon atom.
atoms of the same element that have different masses.
general term for any isotope of any element.
each atom in the gold foil contained a small, dense, positively charged nucleus surrounded by electrons. a small number of the alpha particles directed toward the foil were deflected by the tiny nucleus (red arrows). Most of the particles passed through undisturbed(black arrows).
Planetary model
radius goes up
-nucleus in center
electron cloud
-alpha:positive charge
2prot, 2neut.
-beta : negative charge
Model: electrons aren't just randomly arranged. An atom fills a space (quantum model)
Quantum Model
bohr different energy amounts p1 p2 p3 nucleus at center
average atomic mass
number given on periodic tables. weighted average of atomic masses of naturally occurring isotopes of an element.
amount of a substance that contains as many particles as there are atoms.
Avogadro's Number
the number of particles in exactly one mole of a pure substance. 6.022 x 10 /23.
Molar Mass
mass of one mole of a pure substance.
gram/mole conversion
moles to grams
mol of element X grams/ mol
grams to moles
grams of element X mol/grams
moleular weigh
weight in atomic mass units