Quest #2 Flashcards
Rules for Sig Fig
#1 All non-zero digits are significant #2 Any zero that falls b/w two sig digs is also sig #3 Zeros to the right of the decimal place and to the right of a significant dig are sig. #4 Zeros to the left of the decimal place are not significant unless the decimal point is explicitly written.
Sig Fig Calculations
Mult/Div - The answer to the calculation can only have as many significant digits as the numb. in the calc. w/ the least # of sig digs
Sig Fig Calculations
Add/Sub- The answer to the calc. can only have as many decimal locations as the # in the calculation w/ the least # of decimal places.
Order of Operations
P.E.M.D.A.S.
Exact Numbers
Defined quantities (e.g. Unit conversions, 1cm =1x10-2) and (i.e., counting: 10 chairs) are exact.
Inexact Numbers
Any property based on measurement (mass, volume, pressure, density, etc…)
-subject to the rules for sig figs
Matter
anything that has mass (“weight”) and takes up space (“volume”)
States of Matter
Solid- rigid; has a fixed shape and volume
Liquid- take shape to its container and has a definite volume
Gas- no fixed volume or shape, takes shape and volume of its container
Compounds
Elements which bond together to form compounds, constant composition no matter where they are found.
Mixtures
something that has a variable composition.
Pure Substance
-substances that will always have the same composition
Homogeneous Mixture
a mixture which is same throughout.
ex. salt in water
Heterogeneous Mixture
regions of a mixture are not the same throughout
ex. sand in water
Physical Property -substance can change with out becoming a new substance
physical properties; odor, color, volume, state (gas, liquid, or solid), density, melting point, and boiling point
Chemical Property- ability to change into a diff substance
used to describe a pure substance. Refers to its ability to from new substances
Physical Change
involves a change in one or more physical properties, but no change in fundamental components that make up the substance. The most common physical changes are changes of state: solidliquidgas
Chemical change
involves a change in fundamental components of the substance; a given substance changes into different substance or substances. Also called reactions.
ex. plants growing, wood burning, silver tarnishing
Distillation - a separation process for homogeneous mixtures or pure substances
ex. physical change
Filtration- method used for separating a heterogeneous mixture
ex. physical change
Dalton's Atomic Theory #1 Elements are made of tiny particles called atoms #2 All atoms of an element identical #3 Atoms of different elements are not the same
#4 Atoms of elements can combine w/ atoms of other elements to form compounds. A compound always has the same relative #'s and types of atoms. #5 Atoms are indivisible in chemical processes, that is atoms are not created or destroyed in chemical reactions. Chemical reactions just change the way the atoms are grouped together.
Law Conservation of Mass
that mass is neither created nor destroyed in chemical reactions. In other words, the mass of any one element at the beginning of a reaction will equal the mass of that element at the end of the reaction.
Law of Constant Composition
A given compound always contains the same proportions (by mass) of the elements
- states of matter can be changed form one for to another
- mixtures can be separated or made
- pure substances can be decomposed
- total amount of mass remains constant
Metals
Groups 1- some of 16
Metalloids
Group 14 - 17 -(stair-step) Si-Silicon Ge- Germanium As- Arsenic Sb- Antimony Te- Tellurium Po- Polonium
Non-metals
Group 13-18 B-Boron C-Carbon O-Oxygen P-Phosphorus
