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Matter Introduction Table of Contents Reference

Matter and Measurements

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MatterIntroductionTable of ContentsReference

IntroductionMatter, the stuff of which the universe

is composed, has two characteristics: It has mass, and it occupies space. Matter comes in a great variety of forms: the stars, the air that you breathing, the gasoline that you put in your car, the chair on which you are sitting, and so on.

It is surprising that the basic building blocks in the cake are very similar to the components of air.

Table of Contents Units of Measurement Dimensional Analysis Uncertainty in Measurement Types of Mixtures Separation of Mixtures

Units of Measurement English System – is the most widely

used system in the United States of America.

Metric System – is used in most of the rest of the industrialized world.

SI units – or International System; the most comprehensive system of units. This is based on the metric system and units, & derived from the metric system.

S.I. UnitsPhysical Quantity

Name of Unit Abbreviation

Mass Kilogram Kg

Length Meter m

Time Second s

Temperature Kelvin KSome fundamental SI Units

S.I. Units and Conversion Factors

Length SI Unit: Meter (m)

1 meter = 1.0936 yards

1 centimeter = 0.39370 inch

1 inch = 2.54 cm

1 kilometer = 0.62137 mile

1 mile = 1.6093 km= 5280 feet

S.I. Units and Conversion Factors

Mass SI Unit: Kilogram (kg)

1 kilogram = 1000 grams= 2.2046 pounds

1 pound = 453.59 grams= 0.45359 kilogram= 16 ounces

1 atomic mass unit = 1.66057 x 10 -27 kilograms

Volume SI Unit: Pascal (Pa)

1 liter = 10 -3 m3

= 1 dm3

= 1.0567 quarts

1 gallon = 4 quarts= 8 pints= 3.7854 liters

1 quart = 32 fluid ounces= 0.94635 liter

S.I. Units and Conversion Factors

Pressure SI Unit: Pascal (Pa)

1 atmosphere = 101.325 kilopascals= 760 torr (mm Hg)= 14.70 pounds per square inch

S.I. Units and Conversion Factors

Energy SI Unit: Joule (J)

1 joule = 0.23901 calorie

1 calorie = 4.184 joules

SI PrefixesMultipl

ePrefix Symbo

lMultipl

ePrefix Symbo

l

10 Deca da 10-1 Deci d

102 Hecto H 10-2 Centi c

103 Kilo K 10-3 Milli m

106 Mega M 10-6 Micro µ

109 Giga G 10-9 Nano n

1012 Tera T 10-12 Pico p

1015 Peta P 10-15 Femto f

1018 Exa E 10-18 Atto a

1021 Zetta Z 10-21 Zepto y

1024 Yotta Y 10-24 Yocto z

Sample Exercise I Suppose we know that the height of

Angel falls is 3212 feet and we need to find its height by miles.

use: 1 mi = 5280 ft 1 mi

3212 ft x 5280 ft = 0.6083 mi

Sample Exercise II Problem: 

How many grams are in an eighth of a kilogram? 

Solution: 

There are 1000 grams in 1 kilogram. Set up the conversion so the desired unit will be cancelled out. In this case, we want g to be the remaining unit. 

mass in g = (mass in kg ) x (1000 g/1 kg) 

Note how the kilograms unit will be cancelled out in this equation. 

mass in g = (1/8 kg) x 1000 g/kg mass in g = (0.125 kg) x 1000 g/kg mass in g = 125 g 

Answer: 

There are 125 grams in an eighth of a kg.

Sample Exercise IIIProblem: 

What is the volume of a 5 gallon bucket in liters? 

Solution: 

1 gallon = 3.785 liters 

Set up the conversion so the desired unit will be cancelled out. In this case, we want liters to tbe the remaining unit. 

volume in L = (volume in gal) x (3.785 L/1 gal) volume in L = (5 x 3.785) L volume in L = 18.925 L 

Answer: 

A 5 gallon bucket contains 18.925 liters.

Uncertainty in MeasurementPerson Result of Measurement

1 2.85 cm

2 2.84 cm

3 2.86 cm

4 2.85 cm

5 2.86 cm

The last number in measurements that used measuring devices is usually based on visual estimate, thus, the result may be different when another person makes the same measurement.

Uncertainty in MeasurementCertain Numbers – digits that are

the same regardless of who made the measurement.

Uncertain Number – digit that is estimated and can vary.

A measurement always has some degree of

uncertainty.

Random Uncertainties: result from the randomness of measuring instruments. They can be dealt with by making repeated measurements and averaging. One can calculate the standard deviation of the data to estimate the uncertainty.

Systematic Uncertainties: result from a flaw or limitation in the instrument or measurement technique. Systematic uncertainties will always have the same sign. For example, if a meter stick is too short, it will always produce results that are too long.

Types of Uncertainties

Absolute and Percent Uncertainties If x = 99 m ± 5 m then the 5 m is

referred to as an absolute uncertainty and the symbol σx (sigma) is used to refer to it. You may also need to calculate a percent uncertainty ( %σx):

%5%100m99

m5%

x

Types of MixturesMixture - something that has variable composition Examples: wood – its composition varies greatly depending on the three from which it originates.coffee – it can be strong, weak, or bitter.Wine – it can be red or pale yellow, sweet or dry.

Types of Mixture

Homogenous Mixture - is the same or uniform throughout.- it is also called as a solution.

Example:When we dissolve salt in water and

stir well, all regions of the resulting mixture have the same properties.

Heterogeneous Mixture- contains regions that have

different properties from those of other regions.Example:

When we pour sand into water, the resulting mixture has one regions containing water and another, containing mostly sand.

Types of Mixture

Separation of MixturesHere is the two most common method in separating mixtures.

Distillation- a method for separating the

components of the mixture that depends on the different boiling points of the substances.

Example:Seawater is water containing

dissolved minerals. We can separate the water from the minerals by boiling, which changes the water to stem (gaseous water) and leaves the minerals behinds as solids. If we collect and cool the steam, it condenses to pure water.

Filtration- a method for separating the

components of the mixture containing a solid and a liquid.Example:

A seawater with a scoop of sand. We pour the mixture onto a filter paper which allows the liquid to pass through and leaves the solid behind.

Sample Exercise II

Classify the following as homogenous or heterogeneous.a. Gasolineb. A jar of jelly beansc. Chunky peanut butterd. Margarinee. The paper on which the question is

printed.

Reference Zumdahl, S., et. al. (2013) World of

Chemistry. USA: Cengage Learning. Silberg,M. (2006) Chemistry: the

molecular nature of matter & change