Measurement

MeasurementMetric units

• The fundamental units :

• length is the meter (m)

• Mass is the gram (g)

• Volume is the liter (l)

• Temperature is degree Kelvin (°K) – but Celsius (°C) is more commonly used

Measurement Metric units

• The metric system is based on the number 10 and therefore a decimal system

• Prefixes precede the root or main word (gram, liter, meter).

• The following prefixes are commonly used in science:

MeasurementMetric units

• Examples:• A millimeter is about how

thick as a toenail.

• A centimeter is about as thick as a dime.

• A kilometer is a little more than half of a mile.

MeasurementConversions

• The base represents gram, liter and meter.

------------------●-------●-------●------●--------●--------●--------------●-----------●---------●-----------●-------●--------●-------●------------*--- Prefix:     Mega                           Kilo      Hecto    Deca       Basic Unit      Deci        Centi      Milli                              MicroAbbrev:      M                                k             h           dc             m, l, g            d              c            m                              mc or  μ

MeasurementConversions

• Moving to the RIGHT ------increase

• Moving to the LEFT -------decrease

MeasurementConversions

• Hint – we are referring to the exponent associated with 10 when we “count” places to move the decimal

• We are NOT counting actual words listed on the chart

For example

• if you have 80 hl and you want to convert to cl then you must move 44 spaces to the right.

• So you move your decimal point 4 spaces to the right.

• Your answer is 800000 cl

For example

• if you have 5mg and you want to convert to g then you must move 3 spaces to the left.

• So you move your decimal point 3 spaces to the left.

• Your answer is 0.005g

MeasurementLength

• The basic metric unit of length is the meter (m).

• DIFFERENCES BETWEEN:– English units – Metric units

MeasurementLength

Volume

• When a figure has three dimensions

(length, width, and height) we can find its volume.

• In the metric system volume can be expressed in terms of liters or cubic centimeters

(cm3 or cc)

Volume• The meniscus is the curved interface

between the water and air.

• This is due to the surface tension and adhesive forces of water as it interacts with its container.                                              

  A: The bottom of a concave meniscus.B: The top of a convex meniscus.

Volume

• In a laboratory you would work with

• pipettes: pipette pump or filling device is used to draw and dispense fluids

Volume

• In a laboratory you would work with

• Graduated cylinders

• Erlenmeyer flasks

• Beakers

Mass

• Mass is a measurement of the amount of matter in an object. It is determined by the molecular structure of the object.

• Not to be confused with…………..

Mass

• Weight is a measure of the gravitational pull on an object. It is not the same as mass.

Mass

• In a laboratory you would work with

Triple beam balance / Electronic scale

Scientific Notation

• Scientific notation uses powers of 10 so very large or small numbers can be expressed concisely.

Scientific Notation

• The number we use as the base for this system is 10. The exponent is the power of the number and is applied to the base.

For example

• Write the following large number using Scientific Notation : 146,000,000,000.– Step 1 :place the decimal after the first digit and drop

all the zeros.

1.46 000,000,000_- Step 2: count the number of places from the decimal

to the end of the number. There are 11 places after the decimal point; therefore the exponent is 11.

1.46 X 1011

For example

0.00000123– Step 1: with small numbers you count from the

decimal the number of zeroes until you reach the first non-zero number

0.00000123 = 1.23 X10-6

Graphing Data

Line graphs have both X axis and Y axis. Each X and Y axis is subdivided into uniform intervals.