Appendix 1 - Measurements. We make QUALITATIVE observations of reactions — changes in color and physical state. We also make QUANTITATIVE MEASUREMENTS , which involve numbers . Use SI units —(International System of Units) based on the metric system. Standards of Measurement.
When we measure, we use a measuring tool to compare some dimension of an object to a standard.
For example, at one time the standard for length was the king’s foot. What are some problems with this standard?
Which tool(s) would you use to measure:
Match L) length M) mass V) volume
____ A. A bag of tomatoes is 4.6 kg.
____ B. A person is 2.0 m tall.
____ C. A medication contains 0.50 g Aspirin.
____ D. A bottle contains 1.5 L of water.
- accuracy report
S.I. Units are:
- related by factors of 10
* Table C of Reference Tables
1 km or 1000 m
10 m 1 km
100 cm or 1 m
1 m 100 cm
Mass vs. Weight
Mass: Amount of Matter
Weight: Force exerted by the mass, only present with gravity
*Thermometer is a molecular speedometer. Shows vibrational energy.
The base unit for time = seconds (s)
60 seconds = 1 minute = 1/60 hour
Heat (q) = 4.18J/gK X g (water) X t
1 calorie = 4.18 Joules
D X V = m