Metric Measurements

Chapter 5

Metric and SI UnitsMETRIC BASE UNITS SI BASE UNITS

(standard for measuring)

Length – meter (m) meter (m)

Mass – gram (g) kilogram (kg)

Volume – liter (L) cubic meter (m3)

Time – second (s) Second (s)

Temperature – Celsius (oC)

Kelvin (K)

Amt of substance – mole (mol)

mole (mol)

Metric Prefixes

Giga (G) 109

Mega (M) 106

Kilo (k) 103

Hecto (h) 102

Deka (da) 101

These units are all LARGER than the base unit

More Metric PrefixesThese units are all SMALLER than the base unit

Deci (d) 101

Centi (c) 102

Milli (m) 103

Micro (μ) 106

Nano (n) 109

Steps for Successful Dimensional Analysis

• Identify the given and write that value including units.

• Build a fraction to be used as the conversion factor. – Remember: the given unit goes on the bottom and the

unknown unit goes on top. – The numerical values are assigned to the units in the

fraction so that the two quantities are equal.

• Multiply the fraction by the given and cancel units where appropriate.

Sample problem

Convert 654 milligrams to grams.• The given is 654 mg.

• The fraction should then have mg on the bottom and g on the top. The numerical values needed to make those quantities equal are 1 (with g) and 1000 (with mg).

1 g

1000mg

• Multiply and cancel units:

654 mg x (1g/1000mg) = 0.654 g

More Info:

• Any equality can make two conversion factors.

• When converting from a unit other than the base unit to a unit other than the base unit, do a 2-step problem (i.e., go through the base unit).