Approximately how many cells in the human body? 10 Trillion

Approximately how many bacterium in a human body’s biome?  100 Trillion

Metric Measurement Review

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 = cm 3  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  cm 3 =mL  mL  L Divide by 1,000 or move decimal to the left 3 places  L  gallons  Appropriate measurements  Inside dimensions

TRIPLE BEAM BALANCE Zeroing balance BEFORE measurement Pointer Zero Mark Adjustment Knob

Triple Beam Balance  Largest  Medium  Small  Add values of three arms to get total Example?  Estimate one place further

Comparing Balances  Triple Beam Balance  Zero  More precise measurement  More human error  Electronic Balance  Zero  Less precise  Less Human Error

Precision of Measurement  100 grams vs grams  100 grams = grams  grams=  Always measure as accurately as possible with equipment  Estimate one place further  Don’t give answers of around 2 when it is

Percent Error  The difference in the accepted value and your value  Divide by accepted value  Multiplied by 100  Your answer 10.5 Accepted value =.5.5/10= 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/cm 3  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