Transcript Graduated Cylinder

SI Units
• International System of Units (SI)
Metric Preferences
Graduated Cylinder
• Measure 26.1mL
Scale
• Weigh the object
Ruler
• Measure the length of the object
Bubble Lab
• Does sugar or salt affect the ability to blow
bubbles?
What are the
steps of the
scientific
method?
• Problem
• The problem is the question we want to
answer
• Must be specific and testable
• Observations
• Objective (using facts), not subjective
(using opinions)
• Quantitative (counting or measuring) and
qualitative
• Hypothesis
• A hypothesis is an educated prediction
based on observations.
• MUST BE TESTABLE.
• Experiment
• An experiment tests the hypothesis
• Controlled variables—factors that are kept
constant
• Ex.
• Manipulated variable—factor that
changes (only have one of these at a time)
• Ex.
• Independent variable—factor that causes
a change
• Ex.
• Dependent variable—factor that changes
(the thing you’re measuring).
• Ex.
• Data analysis
• Data analysis is making judgments or
evaluations about the results of an
experiment
• Use graphs, tables, and statistics
•Conclusion
• A conclusion explains the results of the
experiment
• Tell whether or not the hypothesis was
supported
• Explain sources of error
• Retest (OR revise hypothesis)
• Experiment is redone many times
• Theory
• A theory is a conclusion that is accepted
by many scientists that EXPLAINS
something.
•Law
• A law describes behavior of natural events
PROBLEM
OBSERVATIONS
HYPOTHESIS
EXPERIMENT
ANALYZE DATA
DRAW CONCLUSIONS
RETEST
THEORY
DISCARD
Accuracy vs. Precision
• Accuracy: How close to the real value
• Precision: How close a series of measurements are
to each other
Scientific Notation
• Method of writing very small or very large numbers
– A positive exponent means the decimal moved to the left.
– A negative exponent means the decimal moved to the right
Scientific Notation
• 602,200,000,000,000,000,000,000 = ?
– Step 1: Make the Coefficient less than 10 and more
than 1.
– Step 2: Find out how many places over the decimal has
to move to give you the number in step 1.
Scientific Notation
① 5,300,000 = ?
② 4,302,000,000 = ?
③ -24,500 = ?
④ .000034 = ?
⑤ -.0000007 = ?
Scientific Notation
① 5.3 x 104 = ?
② 7.02 x 108 = ?
③ -3.21 x 103 = ?
④ 7.093 x 10-4 = ?
⑤ -5 x 10-3
Scientific Notation
• Addition and Subtraction:
1) Make the exponents the same number
2) Add/Subtract the coefficient
5.3x102 + 2.6x103 =
5.3x102 + 26.x102 =
31.3x102=
3.13x103
Scientific Notation
• Multiplication and Division
1) Add or Subtract exponents
2) Multiply or Divide coefficients
Multiply
5.2x102 x 4.8x104 =
(5.2 x 4.8) x10(2 + 4)
3)=
24.96x106
2.496x107
Divide
5.0x104 ÷ 2.5x103=
(5.0 ÷ 2.5) x10(42.0x101
Scientific Notation
① 5.6x104 + 4.3x102 = ?
② 4.0x106 – 8.3x105 = ?
③ 2.3x105 x 4.3x106 = ?
④ 8.2x1012 ÷ 4.1x107 = ?
Significant Figures
– Rounding Numbers:
-Round up if the digit to the right is between 5-9
59.48  59.5
-Don’t change the number if the digit is between 0-4
3.84  3.8
Significant Figures Tell You What Number To Round To!
Significant Figures
• All Non-zero numbers (1,2,3,4,5,6,7,8,9) are significant
• Zeros –
1) Front of number are NEVER significant
0.0071, 0.42, .000099 all have 2 sig. figs
2) Middle of number are ALWAYS significant
7003, 40.79, 1.503 all have 4 sig. figs
3) End are SOMETIMES significant
At end AFTER decimal, ALWAYS significant
36.00, 1.010, 9.000 all have 4 sig figs
At end BEFORE decimal, NEVER significant
300, 7000, 20000 all have 1 sig fig
Significant Figures
① 5.30 = ?
② 76009.0 = ?
③ 1900 = ?
④ .0000000891 = ?
Significant Figures
• Addition and Subtraction
– Match the number with the least number of decimals
• Ex:
13.21 + 4.1 = 17.3
13.21 + 4.100 = 17.31
13.21 + 4 = 17
• Multiplication and Division
– Match value with fewest number of sig figs
• Ex:
2.00 x 11 =22
2.00 x 11.0 = 22.0
2 x 11 = 20
BIG
1000
k
kilo
100
h
hecto
10
dk
deca
1
BASE
(m, g, L)
.1
d
deci
.01
c
centi
.001
m
milli
SMALL
How do you
convert
between metric
units?
1. Determine whether you are going
up the ladder or down the ladder.
• If you go up, move the decimal to the
left.
• If you go down, move the decimal to the
right.
2. Use the ladder to determine how
many places to move the decimal.
• The number of steps on the ladder is
equal to the number of decimal places.
3. Write the correct units with your
answer.
Conversions
• How many quarters make up $2?
• How many dimes make up $3?
• How many inches make up 2ft?
Conversions
Convert 892cm to meters……
①Make the units cancel to get the units you want
②Find the conversion factor
1) Which is bigger?
(This will have the value of 1)
2) Which one is smaller
(This will have the big number)
3) What is the difference between them
(Count how many steps you take, each one is
101 more)
Conversions
① 23mL = _____ L
② 45km = _____ cm
③ 78.1cm = ______ mm
④ 750dg = _____ mg
⑤ .073m = ______ mm
Conversions
① 8.9g/cm3 = _______ kg/m3
② 4.23m/L = _______ cm/mL
③ 19.6cm/L = ______ m/mL
④ 2.5g/m3 = ______ g/cm3