Chapter 2 Standards CHEM.A.1.1.3 Utilize significant figures to communicate the uncertainty in a quantitative observation. 3.1.10.D Apply scale as a way of relating concepts and ideas to one another by some measure. • Apply dimensional analysis and scale as a ratio. • Convert one scale to another.

Section 2.1 Units of Measurement Chapter 2 Data Analysis Section 2.1 Units of Measurement

Objectives Define SI base units Explain how adding a prefix changes a unit Compare derived units for volume and density

Metric System Units for scientific measurements Developed in France in 18th century Unlike English system

SI Units International agreement Updated metric system 7 Base Units

Base Units

Prefixes Attach to metric unit You will need to know: milli centi kilo

Prefixes

Length and Mass Length SI Unit  meter (m) 1 mile = 1.61 km 1 mile = 5280 ft Mass SI Unit  kilogram (kg) 1 kg = 2.2 lbs

Celsius Scale Everyday scale in most countries Used often in scientific studies

Fahrenheit /Celsius

Kelvin Scale SI temperature scale Zero is the lowest obtainable temperature Absolute Zero

Kelvin to Celsius K = C + 273.15

Derived Units Unit derived from a combination of base units Ex: Volume and Density

Volume 1 milliliter = 1 cubic centimeter 1 mL = 1 cm3

Density Density = Mass/Volume g/cm3 g/mL

Homework Temp Conversions/ Density Worksheet