Atoms Quiz Flashcards
Democritus (major contribution including specific experiment)
-prove the existence of atoms
-theorized atoms were tiny and indivisable
-atomos
Democritus (model)
atomic model (just a circle)
Democritus (how it changed from the previous model)
first atomic model created
Dalton (major contribution including specific experiment)
Daltons 4 part theory:
1.All Matter is Composed of Atoms (false)
2. Atoms of a Given Element are Identical (false)
3. Compounds are Formed by Combining Atoms (true)
4. Chemical Reactions Involve Rearrangement of Atoms (true)
-nitric oxide experiments
Dalton (Model)
Billard Model just a circle
Dalton (how it changed from the previous model)
model didn’t change but the understanding did
Thompson (major contribution including specific experiment)
-discovered the electron
-did this using the cathode ray tube experiment
-proposed atoms are not inadvisable
Thompson (model)
The plum pudding model. Was a circle with electrons suspended in it.
Thompson (how it changed from the previous model)
said there were smaller particles inside an atom
Rutherford (major contribution including specific experiment)
-used the gold foil experiment
-atom mass is in the tiny positively charged center
-discovered the proton
Rutherford (Model)
nuclear model. was a circle with positively charged protons in the middle and electrons on the outside
Rutherford (how it changed from the previous model)
electron is orbiting around the positively charged center
Bohr (major contribution including specific experiment)
-electrons orbit the nucleus at fixed energy levels
-light come when electrons jump levels
-built on the gold foil experiment
Bohr (Model)
Bohr model (planetary model). Kind of like the model we now use.
Bohr (how it changed from the previous model)
electrons only orbit at fixed levels
Chadwick (major contribution including specific experiment)
-discovery of the neutron
-also discovered that it was neutral
-beryllium experiment
Chadwick (Model)
Chadwick model. It had neutrons and protons in the nucleus.
Chadwick (how it changed from the previous model)
built on the Rutherford model. added neutron the the nucleus.
Order of atomic discoveries names
Democritus, Dalton, Thompson, Rutherford, Bohr, Chadwick
Conservation of mass
whenever matter changes, the total mass of the products of the change is the same as the total mass of the reactants.
Law of Definite proportions
every chemical compound contains fixed proportions (by mass) of its constituent elements. (ex. table salt at home is the same as table salt at school)
What holds the nucleus together
strong nuclear force
what keeps the electrons in orbit
electromagnetic force
weight of proton
1 AMU
weight of neutron
1 AMU
weight of electron
0 AMU
AMU=
atomic mass unit
about amu’s
-1 AMU is very close to the mass of a p or n
-but not quite (the atomic mass has electrons in it too)
what is the atomic number
the number of protons in an element. it defines the element
what does the atomic number mean in a neutral atom
it means it is the number of electrons
what is the mass number
mass number is the total protons and neutrons in an atom. It goes above the letter in nucleur notation and is after the hyphen in hyphen notation. you can also round the decimal under the letter to get
what are isotopes
they are atoms of the same element with different numbers of neutrons
Nuclear Notation
mass # is above then the symbol them the atomic number is below
what does an ion look like
a + or - number with the element symbol
ion
gained or lost and electron
if you gain an electron
it becomes smaller because electrons are negative
if you lose an electron
it becomes bigger because electrons are negative
Hyphen Notation
another way to label isotopes. carbon-14. means that this carbon has a mass number of 14
electrons (what we know)
-electrons further from the nucleus have a higher energy
-further levels can hold 2n squared electrons where n is the level
Law of multiple proportions
a.k.a. daltons law
whenever two elements from more than one compound the different masses of one element that combine with the same mass of the other element are in the ratio of small whole numbers
Average atomic mass
weighted average mass of an element isotope, measured in AMU’s. is the decimal under the letter on the periodic table
How to find protons
atomic number
how to find electrons
atomic number if neutral
How to find neutrons
mass number-atomic number
weighted averages
(abundance 1)x(mass1)+(abundance 2)+(mass 2) etc…
Mole
1 mol of a thing= 6.02x10e23 of those things
Avogrados number
6.02x10e23
Molar Mass
1 mole=molar mass in g
Gases at STP number
22.4 L
