Day 2 – Meet the Elements
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Warm-up
Pick up the chemistry pretest
Turn in your signed syllabus and lab safety forms
if you have them
Pick up your name tag and head to your
assigned seat
If you were not in class the first day come see
Mr. Burkhead!
We will spend approximately 40 minutes on the
pretest, no need to guess if you don’t know the
answers
Last half of class we’ll start the periodic table
scavenger hunt
Day 2 – Meet the Elements
Key Vocab
Atom: smallest unit of a substance that maintains its
identity
Element: pure substance containing only one kind of
atom; found on the periodic table
Periodic table: organization of elements by group
(vertical columns) and period (horizontal rows)
Note: We’ll cover all these concepts in more detail
next unit
Day 2 – Meet the Elements
Information provided for each element on the
periodic table includes identity of the element
(name and/or symbol), atomic number, and
atomic weight.
Matter and Measurement
Warm-up 9/1 and 9/2
What does chemistry mean to you? What do
you think we will be studying in this class?
• Jot down a few ideas in your notebook then
pair-share with someone at your table.
• Prepare to share your answer with the class!
Matter and Measurement
Warm-up 9/1 and 9/2
Chemistry is the study of matter and its
interactions.
Matter is anything that has mass and volume
(anything that takes up space essentially).
In a nutshell, chemistry is the study of the
physical world around us!
Matter and Measurement
Unit Learning Targets
1) Categorize matter as elements, compounds,
or mixtures
2) Identify and distinguish different properties
and changes of matter
3) Utilize SI units, significant figures, and
scientific notation
4) Perform unit conversions using dimensional
analysis
5) Determine the density of a substance
experimentally
Matter and Measurement
Unit Vocabulary (Chapter 1 and 2)
Chemical change
Atom
Physical change
Change of state
Extensive property
Significant figures
Intensive property
Scientific notation
Compound
Accuracy
Element
Precision
Mixture
Density
Activity: Define in your own words and provide
an example for the vocab above. Use index or
pages 25 and 58 to locate vocab in the text.
Matter and Measurement
Warm-up 9/3-9/4
Name one metal, one non-metal, one metalloid,
one noble gas, the lightest element, and an
element that is liquid at room temperature.
Matter and Measurement
Learning Target #1
Categorize matter as elements, compounds,
heterogeneous mixtures, or homogeneous
mixtures.
Matter and Measurement
A mixture is a blend of two or more pure
substances that retain their own identity and
properties.
Example: Jot down in your notebook some
examples of a mixture.
Matter and Measurement
A mixture is a blend of two or more pure
substances that retain their own identities and
properties.
Example: air, blood, salt water, soil
Matter and Measurement
A homogeneous mixture (homo=same) is
uniform throughout, like the different air
particles in air while . . .
A heterogeneous mixture (hetero=different) is
not uniform throughout, like soil where heavier
particles tend to settle in lower soil layers.
Matter and Measurement
Pure substances have fixed compositions and
characteristic properties unlike mixtures that can
vary due to the mix.
Element: pure substance containing only one
atom (found on the periodic table)
Compound: pure substance containing more
than one kind of atom chemically bonded
together
Matter and Measurement
Atomic level view
of elements,
compounds, and
mixtures
Each colored
sphere represents
one kind of atom
Matter and Measurement
Matter and Measurement
Warm-up 9/8-9/9
What are some methods you could use to
separate the components of a heterogeneous
mixture? A homogeneous mixture? A
compound?
Be as specific as you can!
Matter and Measurement
Learning Target #2
Identify and distinguish different properties and
changes of matter
Matter and Measurement
Physical separation is a physical change where
the substance does NOT change its identity.
Examples: Grinding, cutting, melting, boiling,
sorting, filtering, etc.
Chemical reactions are chemical changes where
the identity of a substance DOES change.
Examples: rusting, burning, decomposition,
cooking, acid neutralization, etc.
Matter and Measurement
Phase changes are often confused as chemical
changes but the substances do NOT change
identity.
Matter and Measurement
http://vital.cs.ohiou.edu/steamwebsite/downloa
ds/ChangeLab.swf
Matter and Measurement
Physical properties can be observed or
measured without changing the identity of the
substance (no chemical change necessary).
Examples: mass, volume, state, solubility
Chemical properties determine how a substance
may change its identity during a chemical
change.
Examples: flammability, reactivity, toxicity
Matter and Measurement
Extensive properties depend on the amount of
matter that is present. Mass, volume, and
amount of energy in a substance are extensive
properties.
Intensive properties do not depend on the
amount of matter that is present and can be
used to identify a substance. Density, melting
point, boiling point, and conductivity are
intensive properties.
Matter and Measurement
Warm-up 9/10 and 9/14
Pick up and complete “Hypothesis Worksheet”
Matter and Measurement
Learning Target #3
Utilize SI units, significant figures, and scientific
notation
Matter and Measurement
SI Units are standardized units used by scientists
all over the world.
Length = meter (m)
Amount = mole (mol)
Mass = kilogram (kg)
Current = ampere (A)
Time = second (s)
Luminosity = candela
Temperature = Kelvin (K)
Other units can be derived from these base
seven units.
Matter and Measurement
SI Units may use metric prefixes to make larger
and smaller numbers more convenient.
Matter and Measurement
Accuracy vs. Precision
Accuracy refers to how close a measurement is
to the correct or accepted value.
Precision refers the closeness of a set of
measurements.
Matter and Measurement
Warm-up 9/15 and 9/16
Accuracy is quantitatively measured by
calculating a percent error.
Percent error = │(Actual – Experimental)│× 100
Actual
Example: A student experimentally determines
that the density of a substance is 1.40 g/mL.
The accepted value is 1.36 g/mL. What is the
student’s percent error?
Matter and Measurement
Warm-up 9/15 and 9/16
Percent error = │(Actual – Experimental) × 100
Actual
Example: A student experimentally determines
that the density of a substance is 1.40 g/mL.
The accepted value is 1.36 g/mL. What is the
student’s percent error?
Percent error = (1.40-1.36)× 100 ÷ 1.36
Matter and Measurement
Significant figures consist of every digit that has
been measured plus one more digit that has
been estimated.
Matter and Measurement
Matter and Measurement
Warm-up 9/17 and 9/21
Density = mass (g) ÷ volume (mL)
A student determining the density of an unknown
measures a mass of 10.10 g and a volume of 8.2 mL.
How many sig figs does each measurement have?
What is the experimental density of the unknown?
Matter and Measurement
Warm-up 9/17 and 9/21
Density = mass (g) ÷ volume (mL)
A student determining the density of an unknown
measures a mass of 10.10 g and a volume of 8.2 mL.
How many sig figs does each measurement have?
What is the experimental density of the unknown?
10.10 g has 4 sig figs
8.2 mL has 2 sig figs
D = m/v = 10.10 g/8.2 mL = 1.2 g/mL
Matter and Measurement
Scientific notation is used to write very large
and very small numbers in short-hand form.
Why do we need this notation?
Powers of Ten
Matter and Measurement
Converting into Scientific Notation
• Only one digit (non-zero) should be written
on the left of the decimal point.
• If you moved the decimal to the RIGHT you
will write a negative exponent.
• If you moved the decimal to the LEFT you will
write a positive exponent.
Matter and Measurement
Matter and Measurement
Using a calculator
The class set calculators allow you to write scientific
notation by hitting the 2nd button followed by the
EE button.
https://www.youtube.com/watch?v=BW55IniDb2g
The link above goes to a Youtube tutorial for
additional help.
Matter and Measurement
Warm-up 9/22 and 9/23
What is a more reasonable mass for a single carbon
atom, 1.99 x 1023 g or 1.99 x 10-23 g? Explain why.
The sun is 152000000 km away from Earth. How
many meters is that? Provide your answer in
scientific notation (1 km = 1000 m)
Matter and Measurement
Warm-up 9/22 and 9/23
What is a more reasonable mass for a single carbon
atom, 1.99 x 1023 g or 1.99 x 10-23 g? Explain why.
Large negative exponents are very small numbers.
The sun is 152000000 km away from Earth. How
many meters is that? Provide your answer in
scientific notation (1 km = 1000 m)
1.52 x 1011 m
Matter and Measurement
Learning Target #4
Perform unit conversions using dimensional
analysis.
Matter and Measurement
Dimensional analysis
A systematic approach to solving calculations
using units and conversion factors.
Matter and Measurement
Matter and Measurement
Example!
How many seconds in a day?
Step 1: Determine the known (given) and unknown (what
you’re solving for)
Matter and Measurement
How many seconds in a day?
Step 1: Determine the known (given) and unknown (what
you’re solving for)
1 day is the known, # of seconds is the unknown
Step 2: Write needed conversion factors = 1
Matter and Measurement
How many seconds in a day?
Step 1: Determine the known (given) and unknown (what
you’re solving for)
Step 2: Write needed conversion factors = to 1
Step 3: Set up math using conversion factor to cancel out
the unit you have and convert to the desired unit.
Matter and Measurement
How many seconds in a day?
Step 1: Determine the known (given) and unknown (what
you’re solving for)
Step 2: Write needed conversion factors = to 1
Step 3: Set up math using conversion factor to cancel out
the unit you have and convert to the desired unit.
1 day x 24 hours x 60 minutes x 60 seconds =
1 day
1 hour
1 minute
Step 4: Cancel units and solve by multiplying all factors on
the top (numerator) and dividing by factors on the bottom
(denominator)
Matter and Measurement
How many seconds in a day?
Step 1: Determine the known (given) and unknown (what
you’re solving for)
Step 2: Write needed conversion factors = to 1
Step 3: Set up math using conversion factor to cancel out
the unit you have and convert to the desired unit.
Step 4: Cancel units and solve by multiplying all factors on
the top (numerator) and dividing by factors on the bottom
(denominator)
86400 seconds!
Matter and Measurement
Warm-up 9/24 and 9/28
1. What is the metric (and SI) unit for length
and its symbol?
2. What is the metric (and SI) unit for mass and
its symbol?
3. What is the metric (and SI) unit for volume
and its symbol?
Matter and Measurement
Warm-up 9/24 and 9/28
1. What is the metric (and SI) unit for length
and its symbol? Meter (m)
2. What is the metric (and SI) unit for mass and
its symbol? Gram (g)
3. What is the metric (and SI) unit for volume
and its symbol? Liter (L)
These are all called base units and all can be
modified using metric prefixes.
Matter and Measurement
Matter and Measurement
Extra Practice
1. Click on the link below
http://nursing.flinders.edu.au/students/stud
yaids/drugcalculations/page.php?id=1
2. Click on Quiz 2: Converting Metric Units
Matter and Measurement
Warm-up 9/29 and 9/30
1. Pick up lab sheets
2. Read “Beverage Density Lab”
3. Make a guess, which beverage contains the
most sugar? Record in your notebook.
Matter and Measurement
Learning Target #5
Determine the density of a substance experimentally.
Matter and Measurement
Density Lab
Density: amount of matter packed into a given
volume (Density = mass/volume)
Wild guess Question: Which beverage contains the
most sugar?
Research Question: How does sugar concentration of
a beverage affect the density?
Hint: Is sugar less or more dense than water?
Matter and Measurement
Density Lab
Procedure:
1. Measure and record the mass of a 10 mL
graduated cylinder
2. Measure 10.0 mL of each liquid provided into the
graduated cylinder using a pipet
3. Measure and record the mass of each liquid
4. Subtract the mass of the graduated cylinder
5. Divide the mass by the volume (10.0 mL) to get
the density and record
Matter and Measurement
Warm-up 10/1 and 10/5
Review Problem!
What is the density in g/mL of a rock that
weighs 7001.2 kg and displaces 2.80 kL of
water? Give answer with the appropriate # of
significant figures.
How much does the rock weigh in mg expressed
in scientific notation?