Definitions Flashcards
Pure Substance
- large collection of very small particles in which the particles are all alike
- made of elements & compounds.
Element
- one type of substance
- maybe atoms or molecules
Compound
- one type of pure substance
- made of molecules or ions
Particles
- what matter is made of
• atoms
• molecules
• ions
Molecule
- single particle composed of two or more atoms
- held together by very strong bond
Ion
- particle with electric charge
- positive or negative
- monatomic or polyatomic
Monatomic Ion
- atom with an electric charge
- postive or negative
Polyatomic Ion
- molecule with an electric charge
- postivie or negative
Mixture
- particles are not all alike
Homogenous mixture
- mixture that is homogenous in appearance
- uniform compostion
Heterogenous Mixture
- mixture that is heterogenous in appearance
- not uniform in composition
Significant Figures
- Non zero #’s are sig
- Zeros between non zeros are sig
- Zeros left of non zeros are not sig
- Zeros right of non zeros are ambiguous
- Add/Sub measured by decimal places
- Mult/Div measured by sig figs
Units of Mass
Metric: gram (g)
English: pound (lb), ounce (oz)
Units of Length
Metric: meter (m)
English: foot (ft), yard (yd), mile (mi)
Units of Area
Metric: derived units: square meter (m2),
square centimeter (cm2)
English: square inch (in2), square yard (yd2),
square foot (ft2)
Units of Volume
Metric: basic unit: Liter (L)
derived units: meter cubed (m3),
centimeter cubed (cm3)
English: gallon (gal), quart (qt), pint (pt)
Equivalent units
cm3 = cc = ml
Kilo-
1,000 = 1 x 10 exp 3
deci-
0.1 = 1 x 10 exp -1
centi-
0.01 = 1 x 10 exp -2
milli-
0.001 = 1 x 10 exp -3
micro-
0.000001 = 1 x 10 exp -6
nano-
0.000000001 = 1 x 10 exp -9
Kelvin to Celsius
K - 273.15 = C (3 sf’s)
Celsius to Kelvin
C + 273.15 = K (3 sf’s)
Density
mass / volume
Density of Water
1 g/ml
Periodic table: Group (families)
- Vertical columns
- similar chem & physical properties
- Group A: representative elements
- Group B: transition elements/metals
- Group IA = alkali metals (not H)
- Group IIA = alkaline earth metals
- Group VIIA = halogens
- Group VIII = nobles gases (inert gases)
Periodic Table: Periods
- Horizontal rows
Periodic Table: Atomic Mass
- weighted of average of masses of all the isotopes of an element relative to mass of carbon-12
- units of atomic weight (amu)
Diatomic Elements (nonmetal)
- Hydrgen (H2)
- Nitrogen (N2)
- Oxygen (O2)
- Flourine (F2)
- Chlorine (Cl2)
- Bromine (Br2)
- Iodine (I2)
Chemical Change
- Change that results in the formation of one or more new substances
- Different chem & phys property
Kinetic Energy
- Energy of motion
- K.E. = 1/2mv exp 2
Exothermic
- phys or chem change where HEAT is released
Endothermic
- phys or chem change where HEAT is absorb
Law of Conservation of Matter (mass)
- matter is neither created nor destroyed, mass is conserved and changed
Law of Conservation of Energy
- energy is neither created nor destroyed
Matter
- Collection of very small particles
- Three kinds of particles:
• Atoms
• Ions
• Molecules - Two kinds of matter:
• Pure substances
• Mixtures
Formula Unit
- lowest whole number ratio of ions in an ionic compound
- analogous to molecule of a molecular compound
Nucleus
- where protons and neutrons are located
- electrons located outside of nulceus
Isotope
- atom of same element that differs in number of neutrons
Valence Shell
- outermost occupied shell of atom
Valence Electron
- outermost electron in Valence shell
Atomic number
- identity. Number of protons in nucleus
- equal number of electrons in neutral atom
Mass number
- Sum of protons and neutrons
Atomic mass
- weighted average of masses in an atom/molecule
- compared to Carbon-12 (12.00000 amu)
Ion
- atom (molecule) that lost or gained electrons for a charge
Cation
- positively charged ion
Anion
- negatively charged ion
Ionic bond
- metal to nonmetal; metal transfers electrons to nonmetal
Covalent bond
- two nonmetals; share electrons
Neutral atom
- atom with no net charge
- equal number of electrons and protons
Formula unit
- basic unit of ionic compounds
- smallest electrically neutral collection of cation/anion in compound
Molecular mass
- average mass of molecules in compound
Mole
- mass in grams = atomic mass in amu
- avogardo’s number 6.022 x 10e23
Empirical formula
- formula for a compound that gives the smallest whole number ratio of each atom
Molecular formula
- formula for compound that gives specific number of each atom in molecule
