Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Do you really want to delete this prezi?
Neither you, nor the coeditors you shared it with will be able to recover it again.
Make your likes visible on Facebook?
You can change this under Settings & Account at any time.
Chapter 3: Scientific Measurement
Transcript of Chapter 3: Scientific Measurement
, a given number is written as the product of two numbers:
A coefficient and 10 raised to a power
Ex: the number 702,000,000,000,000,000,000,000 can be wrtten as 7.02 x 10^23
The coefficient is 7.02
The power of 10 or exponent is 23
How do you write numbers in scientific notation?
The coefficient is always a number greater than or equal to one and less than ten. The exponent is an integer.
indicates how many times the coefficient must be multiplied by 10
indicates how many times coefficient must be divided by 10.
Multiplication and Division
To multiply numbers written in scientific notation multiply the coefficients and add the exponents
To divide numbers written in scientific notation, divide the coefficients and subtract the exponent in the denominator from the exponent in the numerator
is a quantity that has both a number and a unit
Measurements are fundamental to the experimental sciences
In Chemistry you often encounter
a single gram of hydrogen contains 602,000,000,000,000,000,000,000 hydrogen atoms
the mass of an atom of gold is 0.000 000 000 000 000 000 000 327 gram
Krystiana Ceselka and Jasmine Varma
Addition and Subtraction
When adding and subtracting numbers in scientific notation without a calculator
be the same
be aligned before you add and subtract
Accuracy and Precision
is the measure of how close a measurement comes to the actual or true value of whatever is measured
is a measure of how close a series measurements are to one another, irrespective of the actual value
How do you evaluate accuracy and precision?
: the measured value must be compared to the correct value
: must compare the values of two or more repeated measurements
is the correct value for the measurement based on reliable references
the value measured in a lab
is the difference between the
is the absolute value of the
divided by the
multiplied by 100%
in a measurement include all of the digits that are known, plus a last digit that is estimated
Why must measurements be reported to the correct number of significant figures?
Because calculated answers often depend on the number of significant figures in the values used in the calculations
Significant Figure Rules
All digits 1-9 are significant
Embedded zeros embedded between significant digits
Trailing zeros in a number are significant
if the number contains a decimal point
The leading zeros at the beginning of a number are
Zeros following a decimal significant figure
Exceptions to the rule are number with an
number of sig figs
First determine the number of sig figs, then count from the left, and round
< 5: stays the same
> 5: increases by 1
Multiplying and Dividing
Limit and round the the
in any of the factors
Addition and Subtraction
Limit and round your answer the to the
in any of the numbers that make up your answer
Units of Measurement
The standards of measurement used in science are those of the metric system
All metric units are based on multiples of 10
They can be converted between units easily
International System of Units
(SI) is a revised version of the metric system
Scientists commonly use two equivalent units of temperature: the degree Celsius and the kelvin
uses the freezing point of water (0°C) and the boiling point of water (100°C) as reference values
the freezing point of water is 273.15 kelvins (K) and the boiling point is 373.15 K
is the ratio of the mass of an object to its volume
It is an intensive property that depends only on the composition of a substance, not on the size of the sample
is a ratio of equivalent measurements
The measurement in the numerator is equivalent to the denominator
Examples: the ratios
100 cm/1 m
1 m/ 100 cm
What happens when a measurement is multiplied by a conversion factor?
The numerical value changes
The actual size of the quantity measured remains the same
is a way to analyze and solve problems using the units, or dimensions, of the measurements
Many problems in chemistry are conveniently solved using dimensional analysis
What kind of problems can you solve using dimensional analysis?
Conversion problems in which a measurement with one unit is changed to an equivalent measurement with another unit
When multiplying with scientific notation
A) divide the coefficients, subtract exponents
B)multiply coefficients, add exponents
C) subtract exponents, divide exponents
D) add coefficients, multiply exponent
2.The standards of measurements in science are those of the metric system. All metric units are based on multiples of:
3. Conversion factor is:
A) a ratio of equivalent measures
B) the ratio of the mass of an object to its volume
C) a quantity that has a number and a unit
D) a given number written as a product of two numbers
4. What is the formula for converting Celsius to Kelvin?
A) K= C-273
B) K= C*273
C) K= C/273
D) K= C+273
5. If the temperature is 478K, what is the temperature in Celsius?