Vocabulary Flashcards
(125 cards)
Law of Definite Composition/Proportions
compounds are made by combining atoms of two or more elements in a definite proportion or ratio by mass
physical properties
observed with senses; physical state, color, odor, solubility in water, density, melting point, taste, boiling point, hardness
chemical properties
can be observed in regard to whether or not a substance changes chemically; result of reacting with other substances; Ex: iron rusting, nitrogen not burning, gold not rusting, sodium and water react, silver and water don’t react, water can be decomposed by electric current
Law of Conservation of Mass
mass of reactants equals mass of products
Law of Conservation of Energy
energy is neither gained nor lost in physical or chemical changes
Law of Conservation of Mass and Energy
mass and energy are interchangeable under special conditions
Kelvin and Celsius
K = C + 273 C = K - 273
Joule and calorie
1 calorie = 4.18 joules
accuracy
how close you have come to the true value
precision
how repeatable the results are
+/- Sig figs
to the least common place
Mult or Div Sig Figs
least amount
Example of Sig Figs
- all digits except zero
- zeros between nonzero digits
- zeros to the right of the decimal point
Dalton’s Atomic Theory
Matter = small particles called atoms
atoms of an element have similar weight different than other elements
atoms cannot be subdivided, created, or destroyed
atoms of diff elements combine in simple whole number ratios to form chemical compounds
chemical rections: atoms are combined, separated, or rearranged
J.J. Thompson
electron
Rutherford
protons
James Chadwick
neutrons
Niels Bohr
orbitals/energy levels
Henry Moseley
atomic numbers; periodic law: properties of elements are periodic functions of their atomic numbers
isotopes
same number of protons; diff masses bc of neutrons
Heisenberg uncertainty principle
it’s impossible to know both the precise location and precise velocity of a subatomic
Pauli Exclusion Principle
No two electrons can have the same four quantum numbers
Aufbau Principle
an electron occupies the lowest energy orbital that can receive it
Hund’s Rule of Maximum Multiplicity
pairing will occur with the addition of one more electron to each orbital