Exam 1 Flashcards
chemistry
study of matter, its properties, the changes that matter undergoes, and the energy associated with these changes
matter
anything that has mass and volume
solid
fixed shape and volume
liquid
varying shape, fixed volume
gas
no fixed shape or volume
element
simplest type of substance with unique physical and chemical properties; consists of only one type of atom; cannot be broken down into simpler substances by physical or chemical means
molecule
a structure that consists of two or more atoms that are chemically bound together and thus behaves as an independent unit
compound
substance composed of two or more elements that are chemically combined in a fixed ratio by mass (do not retain own identities)
mixture
a group of two or more elements and/or compounds that are physically intermingled (retain own identities)
Dalton’s Atomic Theory of Matter: 1st Postulate
All matter consists of atoms; tiny indivisible particles of an element that cannot be created or destroyed
Dalton’s Atomic Theory of Matter: 2nd Postulate
Elements are composed of one type of atom. Atoms of an element are identical in mass and other properties and are different from the atoms of any other element.
Dalton’s Atomic Theory of Matter: 3rd Postulate
Compounds are formed by the chemical combination of 2 or more atoms in a specific ratio by mass
Dalton’s Atomic Theory of Matter: 4th Postulate
During a chemical reaction, atoms will combine, separate or rearrange to give different substances. Atoms are neither created nor destroyed during a chemical reaction.
Law of Definite (or Constant) Composition
No matter what its source, a particular compound is composed of the same elements in the same parts (fractions) by mass
Law of Mass Conservation
The total mass of substances does not change during a chemical reaction
Law of Multiple Proportions
When different numbers of atoms of elements combine, they must do so in ratios of small, whole numbers
Who discovered the electron and determined the mass/charge ratio?
JJ Thomson with Cathode Rays
Who determined the mass and charge of the electron?
Millikan with Oil-Drop Experiment
Who discovered the atomic nucleus?
Rutherford with gold foil beta particle experiment
Mass Spectrometry
method for measuring the relative masses and abundances of atomic-scale particles
ionic bond
results from transfer of electrons; between metal and nonmetal atoms
covalent bond
results from sharing of electrons; between nonmetal atoms
cation
positively charged ion
anion
negatively charged ion
binary compounds
two elements
ternary compounds
three elements
mole (mol)
amount of a substance that contains the same number of entities as there are atoms in exactly 12g of carbon-12; Avogadro’s number (NA) of anything
molar mass
mass of a mole of a substance’s entities (atoms, molecules, formula units)
empirical formula
simplest formula for a compound that agrees with the elemental analysis
molecular formula
actual number of atoms of each element in a molecule of the compound
combustion analysis
used to measure the amount of carbon and hydrogen in a combustible organic compound
SI Unit Prefix
mega (M)
1x106
SI Unit Prefix
kilo (k)
1x103
SI Unit Prefix
deci (d)
1x10-1
SI Unit Prefix
centi (c)
1x10-2
SI Unit Prefix
milli (m)
1x10-3
SI Unit Prefix
micro (u)
1x10-6
SI Unit Prefix
nano (n)
1x10-9
SI Unit Prefix
pico (p)
1x10-12
