approximately how many cells in the human body? 10 trillion

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