Chapter 1 Flashcards
(23 cards)
John Dalton’s atomic theory (4 things)
1) each element is composed of tiny indestructible particles called atoms (protons (+), neutrons (neutral), and electrons (-))
2) all atoms of an element have the same mass and chemical properties within that particular element-which distinguish it from other elements
3) atoms combine using bonds to create compounds/molecules with simple whole number ratio of atoms/elements
4) atoms of an element cannot be turned into atoms of a different element in a chemical rxn
jj thompson
discovered the electron and that the electron is negatively charged
millikan oil can experiment
discovered that mass of the electron to be 9.11x10^-31kg
becquerel and curie
discovered radioactivity, certain elements spontaneously emit particles such as beta, alpha, and gamma particles
thompson’s plum-pudding model of the atom
a “soup” of positively charged particles where negatively charged particles (electrons) are suspended. Need + and - since elements have a neutral charge
rutherford’s gold foil experiment
tests thompson’s plum pudding model by exposing alpha particles to a thin piece of gold-foil. It proved Thompson’s plum pudding model was not accurate
rutherfords nuclear theory
Gold foil experiment dispelled thompson’s plum pudding model (atom has a lot of empty space, atom has a dense region of matter)
1)positive charged particles are at the center of the atom. A very dense region and comprises all of the atoms mass
2)the empty space is where the electrons are found
3)the number of positive particles equals the number of negative particles (elements are neutral)
neutrons come later to reason out a mass defect-neutrons have no charge.
basic atomic structure
nucleus where protons (+) and neutrons (0) are housed which is surrounded by electrons (-) that form an “e-cloud”
protons
p+, positive charge, mass is 1.67x10^-27kg, relative to 1 amu
neutrons
n0, neutral, mass is 1.672x10^-27, relative to 1amu
electrons
e-, negative charge, ,ass is 9.11x10^-31kg, relative 1/1800amu
because of the amu, only p+ and n0 are used for an atom’s mass. e- do not count.
elemental symbols
top left=atomic mass
bottom left=atomic number
letter=element symbol
atomic number
the number of protons an element has. the # of protons distinguishes one element from another element
atomic mass
the number of protons and the number of neutrons
isotopes
isotopes of an element all possess the same # of protons but differ in the number of neutrons
ions
charged elements, not neutral, that are produced due to difference in # of p+ and e-
electronegativity
an elements inherent desire for electrons. Increases up and to the right on the periodic table. (L of PT=not electronegative, R of PT=very electronegative)
ionic bond
bond between + (cations) and - (anion)…no sharing of electrons. EX: metal and nonmetal.
covalent bond
sharing of electrons since elements are of similar electronegativity. EX: nonmetal and nonmetal
mole
“a chemist’s” dozen
avogadro’s number
- 6.022x10^23 things=1 mol
- you can have a mol of anything
- he found a relationship between the atomic mass of an element and the mol value of the elements. The atomic mass on the periodic table is equal to that many grams per 1 mol.
- the mole allows us to relate atoms to atoms as well as atoms to molecules and molecules to molecules
molecular formulas
shows elements in a molecules (ionic or covalent) and their respective ratio to one another
molecular molar mass
the sum of all the individual atomic molar masses in a molecule
