MEASUREMENTS Flashcards
(56 cards)
The “Absolute temperature scale” begins at absolute zero and only has positive values
Kelvin ( K )
The temperature scale used by science, formally called centigrade, most commonly used scale around the world
Celsius ( oC )
Commonly used scale in the U.S. for our weather reports
Fahrenheit ( oF )
Refers to reproducibility or how close the measurements are to each other
Precision
Refers to how close a measurement is to the real value
Accuracy
Values that are either all higher or all lower than the actual value
Systematic Error
In the absence of systematic error, some values that are higher and some that are lower than the actual value
Random Error
Operation that, under specified conditions, in a first step, establishes a relation between the quantity values with measurement uncertainties provided by measurement standards and corresponding indications with associated measurement uncertainties (of the calibrated instrument or secondary standard) and, in a second step, uses this information to establish a relation for obtaining a measurement result from
Calibration
ratio of mass over volume
Density
Any characteristic of matter that does not depend on the amount of the substance present
Intensive Property
Any characteristic of matter that depends on the amount of matter being measured
Extensive Property
The Density of Water is
1 g/mL
defined as the mass per unit volume of a substance, and it is a physical property of matter
Density
The units of density are commonly expressed as
g/cm for solids, g/mL for liquids, and g/L for gases
Your eye must be level with the volume mark and the pipet vertical. If you are looking up at the pipet, the meniscus will be too high when it appears to align with the mark. It you are looking down at the pipet, the meniscus will be too low when it appears to align with the mark
Parallax error
the simple average of your replicas
The mean
related to the spread in values of replicas of your experiment
The standard deviation
The standard deviation of the mean, σ𝑥̅, is also called the
estimated standard error
measure of the average kinetic energy of molecules in a substance
Temperature
5 types of glasses
- Soda lime glass
- Lead glass
- Borosilicate glass
- Fused silicate glass (Quartz glass)
- Ceramics
A substance that is made from clay and hardened by heat in a furnace maintained at a high temperature
Ceramics
Sand is heated until it melts at 1700°C, and the viscous liquid is cooled immediately which produces a transparent solid with an uneven arrangement of atoms. Properties: Cannot expand or contract easily when there are temperature changes. Difficult to be made into different shapes. High melting point.
Fused silicate glass (Quartz glass)
Boron oxide (B2O3) and sodium carbonate is added to molten silica. Properties: Able to withstand high temperature and chemical reaction. It does not break easily. High melting point. Transparent to light and infrared ray but no to ultraviolet ray.
Borosilicate glass
A mixture of lead(II) oxide, sodium oxide and silica, Lead glass of better quality contains a higher percentage of PbO. Properties: High refractive index and density, Glittering and attractive surface, Very transparent.
Lead glass
