Scientific Reasoning

Question 1

Units of Measurement I

Answer 1

Scientist use the metric system or Systeme International (SI) to measure and record data. The SI base units for mass, length, and time are kilogram, meter, and second. SI units are also used to measure volume of a three dimensional object: length, height, width, which are all measured in length units. Volume of a container is 10 cm x 10 cm x 10 cm = 1000 cm3. SI base unit for volume is liter.

Question 2

Units of Measurements II

Answer 2

SI system also uses prefixes to indicate the size of units. Common Prefixes are:
Kilo=1000
Hecta 100
Deca= 10
1
Deci = 0.1
Centi= 0.01
Mili= 0.001
Micro= 0.0001

Question 3

Dimensional Analysis

Answer 3

Used to convert measurements from one unit to another. A conversion factor expresses the relationship between units that is used to change the quantity without altering the value of the measurement. Example, 5 liters to milliliters we can multiply 5L by 1,000 mL/1L.

Question 4

Volume

Answer 4

The amount of space something takes up.

Question 5

Mass

Answer 5

The measurement of intertia, commonly considered the amount of material contained by an object and causing it to have weight in a gravitational field.

Question 6

Length

Answer 6

Measurement of distance from end to end.

Question 7

SI Units (Systeme International)

Answer 7

International System of Units based on meters, kilograms, seconds, amperes, Kelvin, candela, mole. Known as the metric system.

Question 8

Liter

Answer 8

Measurement of Liquid volume.

Question 9

Selecting a Measurement Tool I

Answer 9

Length is typically measured with a ruler or meterstick. Length is the distance from end to end of an object and is used to describe width, height, and length. Volume can be measured in different ways. Volume of solids can be measured using rulers or metersticks multiplying length, width, and height.

Question 10

Selecting a Measuring Tool II

Answer 10

Measuring volume of liquids in large volumes is a volumetric flaskand small volume volumetric pipette. Graduated cylinders can also be used to measure a range of volumes, they are less accurate than volumetric flask or pipette.

Question 11

Meniscus

Answer 11

Liquids form a meniscus in a measuring tool. Is the curve formed at the top of a liquid in response to its container. The meniscus curve can be upward (concave), downward (convex), or flat, depending on the line you are reading. Ensure the line you are reading is even with the center of the meniscus.

Question 12

Balances

Answer 12

Are used to measure the mass of an object. The mass is the amount of matter in an object. Two types of balances used to measure mass: triple beam balance and electronic balance. Electronic balance is more common because its easier to use.

Question 13

Choosing Appropriate Scale

Answer 13

Important to choose to the most appropriate scaled unit when measuring items. Large mass items would likely be measured using kilograms (kg). Ex: Person has a mass of 75kg than 75,000 g Measuring a few drops of water would be in milliliters than liters. Fingers, insects in milliliters. Height of a door meters. Distance between two towns in Kilometers.

Question 14

Volumetric Pipette

Answer 14

A device used for precise measurement of small amounts of liquid volume

Question 15

Graduated Cylinder

Answer 15

A narrow cylinder used to measure liquid volume.