approximately how many cells in the human body? 10 trillion
TRANSCRIPT
Approximately how many cells in the human body?10 Trillion
Approximately how many bacterium in a human body’s biome?
100 Trillion
Metric MeasurementReview
Metric Prefixes: kilo- to mili-
Metric Prefixes mL Liter
mL are a small unit—how many drops per mL
Liters are a larger unit
Bigger unit of measurement= bigger or smaller number?
Move decimal to the? 7000 mL
Using Graduated Cylinders-Volume
Value of graduation marks (lines) Distance between long lines
Count lines & do simple math
40-20= 20 mL between long lines
10 lines between long lines
20/10= 2 mL per line
Using Graduated Cylinders-Volume
Value of graduation marks (lines) ?
Reading a graduated cylinder Meniscus – The curve of the water
Read at the BOTTOM of the curve
Example=?
Using Graduated Cylinders-Volume Take measurement as precise as
equipment allows
Estimate to the next place
Example=?
Volume of object= difference of first measurement and second
Ex 70.5 & 75.0= difference/volume of ?
Volume through dimensions & equation Volume= Length x Width x Height
Thickness of slide 1mm = cm3
Human error Measurements Calculations
More accurate when there are less steps required because there is less human error Always use equipment that allows you to get the answer you want if possible
Graduated Cylinder for Volume instead of Ruler
Volume by Formula Item too large to use graduated cylinder?
Length x Width x Height
Aquarium cm3=mL
mLL Divide by 1,000 or move decimal to the left 3 places
Lgallons
Appropriate measurements Inside dimensions
TRIPLE BEAM BALANCE
• Zeroing balance BEFORE measurement
• Pointer
• Zero Mark
• Adjustment Knob
Triple Beam Balance
LargestMediumSmall
Add values of three arms to get total Example?
Estimate one place further
Comparing Balances Triple Beam Balance
Zero More precise
measurement
135.15 More human error
Electronic Balance Zero Less precise
135.0 Less Human Error
Precision of Measurement 100 grams vs. 100.0 grams
100 grams = 99.5-100.4 grams 100.0 grams= 100.0-100.04
Always measure as accurately as possible with equipment
Estimate one place further Don’t give answers of around 2 when it is 2.33333
Percent Error The difference in the accepted value and your value
Divide by accepted value
Multiplied by 100
Your answer 10.5 Accepted value 10
10.5-10= .5 .5/10=.05 .05 x 100= 5.0%
Color Challenge & Density Directions should have left you with rainbow with 10mL in each test tube
Left over water in tubes
Inaccurate measurements
Mass & Volume Density Mass/Volume=Density g/cm3
Ruler Errors
1. Hydrogen
2. Nitrogen
3. Neon
4. Carbon
5. Helium Turn Over
6. Oxygen
7. Fluorine
8. Beryllium
9. Boron
10. Lithium
Element Flashcards Set 1
Oxygen O