Who named "atoms" after the Greek word invisible?
What did Democritus theorize about atoms?
That they were everywhere and they were little tiny particles that made up everything
Who did not agree with
Democritus? and instead said matter was what?
What are the 3 basic laws of Chemistry? and Explain.
1. Law of Conservation of mass (Mass can neither be created nor destroyed)
2. Law of Multiple Proportions(Two or more atoms of elements can come together in different ratios that are all whole numbered)
3. Law of Definite Proportions (compounds always contain the same elements in the same proportions by mass)
-Who came up with an "Atomic Theory" to explain the 3 Laws?
-Was this theory correct?
only 3/5 were true
-What are the 5 parts of Dalton's atomic theory?
-Explain why 2 of them are wrong and how the Modern Atomic Theory changed that.
1. All matter is composed of small particles called atoms
2. Atoms of a given element are identical in all properties (isotopes = diff mass)
3.Atoms can not be subdivided, created, or destroyed (Electrons, neutrons, protons)
4. Atoms of different elements combine in simple whole number ratios to from chemical compounds
5. In chemical reactions atoms are combined, separated, or rearranged)
What did J.J. Thompson Discover? and what was his experiment?
-Cathode ray (when charge plates on=no straight and since opposites attract that means electrons negative)
What did Millikan discover? How?
-Discovered charge and mass of electron
-atoms are neutral therefor they must have a positive and negative charge
mass of electron is super small so where mass come from?
What did Rutherford Discover? How?
-Nucleus, Atoms are 99% empty space, Discovered a positive charge
-Gold Foil experiment (Shot alpha (+) particles at foil only 1/1000 would be shot back)
What do electrons do?
What do protons do?
What do neutrons do?
-Form bonds between elements
-equal the overall mass and make the identity of the element
-equal the overall mass
If you change # of neutrons?
if you change # of protons?
If you change # of electrons?
-change mass get isotope
-change charge, mass, and identity
How powerful are the forces holding the nucleus together?
EXTREMELY POWERFUL (E=mc^2)
What is Nuclear Forces?
short range proton-proton, neutron-nuetron, and proton-neutron forces that hold nuclear particles together.
What is the symbol for the atomic number and the atomic number is = to what?
-# of protons
In a neutral atom the number of protons = the what?
# of electrons
Mass # is equal to what?
# of protons + # of neutrons
What are isotopes?
Atoms that contain the same # of protons but a different # of neutrons.
Isotopes can be expressed in two ways, what are they?
Hyphen notation and Nuclear Symbol
How do you write Hyphen notation and nuclear symbol?
-(amu w/ isotopes) OVER (amu normally) with the atomic symbol besides them
Atoms are small so how do we measure them?
According to relativity
What do scientists compare all atoms to in order to get the amu?
The Carbon atoms bc it is the most abundant atom
What is the Carbon 12 scale?
All atoms are compared to the carbon atom and given their amu.
What is an amu equal to?
1/12 of a Carbon atom
How do scientists find the average atomic mass when there are so many isotope elements?
weighted average of atomic massed X their abundance + the other isotopes X their abundence
Define Mole (mol)
amount of substance that contains as many particles as their are in exactly 12 g of Carbon-12
What is Avogadro's Number?
The mol or 6.022 X 10^23 which is exactly the number of atoms of any pure substance in exactly one mole
What is the molar mass?
mass of 1 mol of a pure substance
Know the conversion charts for mols to grams to atoms and such
look at your notes