When recording a measurement, how many significant digits should you record?
What is a significant digit?
all digits that are certain plus the first uncertain digit
When multiplying or dividing numbers, how many significant digits can your answer have?
Has the same number of Sig figs as the number with the smallest Sig figs used in the problem
Describe the 5 methods of physical separation
Distillation, Evaporation, Decantation, Boiling, Chromatography
Name 5 properties that a specific material can be identified by
freezing point, density, atomic mass, condensation point, boiling point, melting point
Name the 7 diatomic elements, what does diatomic mean?
H2, I2, N2, Cl2, Br2, O2, F2 ; 2 atoms
List the 5 properties of metals, where are they located on the Periodic Table? Where is the most reactive metal located?
luster, malleable, ductile, most solids at room temp., conductors of heat & electricity, 3 or fewer valence electrons, to the left, all the way to the left Francium
List the 5 properties of nonmetals, where are they located on the Periodic Table? where is the most reactive metal located?
little to no luster, non-malleable, non-ductile, most gases at room temp., poor conductors of heat & electricity, 5 or more valence electrons, to the right, all the way to the right ;Fluorine
Name and describe the 2 main classifications matter
heterogeneous-different parts, different properties
homogeneous-all properties are the same
Name any 2 materials that can be classified as substances & give 2 ways that they are different from each other
element- can't be broken down by heat vs chemical mean
compound-can be broken down by heat
A combo nation of sugar & water would be classified as:
What are the 2 types of energy transfer that can occur between a system & its surroundings?
Endothermic-heat goes in, requires heat to occur
Exothermic- heat goes out, reaction produces heat (burning of coal)
What is a physical property? Give 5 ex.
characteristics that can be observed without altering the identity of a substance ( color,length, size, volume, mass)
What is a chemical property? Give 5 ex.
characteristics of a substance that can't be observed without altering the make-up of the substance (does it burn, is it toxic, does it react with water, is it acidic, does it rust)
What is a physical change? Give 5 ex.
changes that don't alter the chemical make-up of a substance, generally easy to reverse (chopping, tearing, crushing, mixing, pouring)
What is a chemical change? Give 5 ex.
changes that alters identity (burning, milk souring, aging, growing, rusting)
What are 4 good indications that chemical change has occurred?
gas given off, bubbles, change in temp., precipitation occurs
What are the 3 phases of matter? describe each in their shape, kinetic energy, & spacing of molecules.
gas- molecules far apart, high kinetic energy
liquid- loose molecules, medium kinetic energy
solid-molecules close together, low kinetic energy
Elements are represented by
Compounds are represented by:
Which subatomic particle is involved in a chemical reaction?
When metals react they _______ electrons forming ____ ions called _________.
lose, positive, cation
When nonmetals react they ____ electrons forming ____ ions called _____.
gain, negative, anion
Atoms react to become _____ like the ________ which are in Group I8. This Group has a full outer shell called an ___________. Since they are stable and don't want to react their oxidation number is ___.
stable, noble gases, octet, 0
What is the characteristic ion present in water solutions of all acids?
What is the characteristic ion present in water solutions of all bases?
What are the 5 main reactions types & how do you recognize each type?
composition (element + element), decomposition (compound), single replacement (element + compound), double replacement (compound +compound), combustion (hydrocarbon + ox ----> Co2 + H2O)
What are the 4 pieces of info that a coefficient gives you?
# of moles, # of molecules, # of atoms, volume iff gas or STP
Name the 3 subatomic particles, their charge & their location within the atom
neutron= nucleus, proton (+) = nucleus, Electron (-) - outside nucleus
What is an isotope?
atoms of the same element , but with a different number of neutrons