Chem 151 Exam 1 ACTUAL UPDATED QUESTIONS AND CORRECT ANSWERS
, What are chemists' three central goals and what kind of Analysis- What is this?
questions should be asked? Synthesis- How do I make it?
Modeling- How do I explain it?
intensive property DO NOT depend on the amount of material
Melting point, boiling point, density, color
CHARACTERISTIC
of a material
extensive property Depend on the amount of material
Length, Mass, Area
Independent of the type or identity of the material
Tell you HOW MUCH
quantitative any value recorded directly from a tool is considered quantitative data (numbers
based)
qualitative It includes such descriptions as color as well as observations about texture
changes and anything else that is actually an opinion (try describing the
difference in color between two different blades of grass)
significant figures rules 1. Zeroes in the beginning of a number never count.
2. Zeroes at the end of a number count only if there is a written decimal point.
3. The digits 1 - 9 always count.
4. Zeroes between the digits 1 - 9 always count.
matter anything that has mass and occupies space
substance that object which has mass and occupies space
composition the makeup of something (components)
state its physical form/condition
three states of matter gas, liquid, solid
solid -atoms or molecules pack close to each other in fixed locations
-vibrate but do not move around or past each other
-fixed volume and shape
, What are chemists' three central goals and what kind of Analysis- What is this?
questions should be asked? Synthesis- How do I make it?
Modeling- How do I explain it?
intensive property DO NOT depend on the amount of material
Melting point, boiling point, density, color
CHARACTERISTIC
of a material
extensive property Depend on the amount of material
Length, Mass, Area
Independent of the type or identity of the material
Tell you HOW MUCH
quantitative any value recorded directly from a tool is considered quantitative data (numbers
based)
qualitative It includes such descriptions as color as well as observations about texture
changes and anything else that is actually an opinion (try describing the
difference in color between two different blades of grass)
significant figures rules 1. Zeroes in the beginning of a number never count.
2. Zeroes at the end of a number count only if there is a written decimal point.
3. The digits 1 - 9 always count.
4. Zeroes between the digits 1 - 9 always count.
matter anything that has mass and occupies space
substance that object which has mass and occupies space
composition the makeup of something (components)
state its physical form/condition
three states of matter gas, liquid, solid
solid -atoms or molecules pack close to each other in fixed locations
-vibrate but do not move around or past each other
-fixed volume and shape
