Describing Matter Flashcards
Define Matter
anything that has mass and volume
Group
a column of elements (there are 18)
Periods
a row of elements (there are 7 rows)
Metals
left of the staircase
nonmetals
right of the staircase
metalloids
touch the staircase
transition metals
21-30 39-48 57-80 89 104-109
law of definite proportions
compounds occur in definite properties (CO2 is always 1CO2)
Law of Conservation of mass
Matter is neither created nor destroyed
Who discovered atomic theory and when
John Dalton in 1803
Atomic Theory
All matter is composed. of:
Atoms of the same elements are exactly alike and atoms of different elements are different
Atoms cannot be: subdivided, created, or destroyed
Compounds are formed by joining atoms of two or more elements: in simple whole number ratios
In chemical reactions atoms are combined, separated or rearranged
Identify parts of an atom
Protons-positive
Neautrons-neutral
Electrons-negative
Quarks-smaller particles and come in six forms
Isotopes
Atoms that have the same # of protons, but differ in their neutrons
Atom to Mole
6.02 x 10^23
Ion
When an atom gains or loses an electron (a charged atom)
A negative Ion
anion
A positive ion
cation
What forms do quarks come in
two are “up” (charge of +2/3) or “down” (charge of -1/3)
How do quarks make a proton
UUD (2/3+2/3-1/3=3/3=+1 charge)
Democritus
400 BC Philospher, called smalliest particle “Atoms” (found atoms)
12th century alchemists goals:
turn metals into gold
elixir of life
universal solvent
20th century
discovered atoms consist of charged components-positive and negative
JJ. Thomson
discovered electrons in 1897 and developed the “Plum Pudding Model”
thought electrons were randomly placed throughout the atom
Who did the gold foil experiment and disproved J.J. Thomson theory
Ernest Rutherford
What happened during the gold foil experiment
Rutherford’s two conclusions
The atom is mostly empty space
Protons are densely packed (with neutrons) in the center of the atom
Parts of an atom (their mass and charge)
Proton-1 amu positive +1
Neutron-1 amu neutral 0
Electron-1/2000 amu negative -1
atomic mass unit (1.66x10^-24)
How do protons stick together
u and d quarks have opposite “color charges”
color charge is different and much stronger than electrical charge
the force “strong force” is one of the four forces in nature
Nuclear Reactions
changes that occur in the nucleus
a. fusion- two small nuclei combine and form one large nucleus releasing large amounts of energy (occurs in sun and stars)
b. fission-one large atom splits into 2+ smaller atoms releasing a large amount of energy (occurs in unstable atoms at a constant rate on earth, used in power plants)
whats a mole
a number that provides a bridge between our world and the atomic world
gas to liquid
condensation
liquid to solid
freezing
solid to gas
sublimation
gas to solid
deposition
solid to liquid
fussion or melting
liquid to gas
vaporization
