Day 2 – Meet the Elements Warm-up 1.Pick up the chemistry pretest 2.Turn in your signed syllabus and lab safety forms if you have them 3.Pick up your name

Day 2 – Meet the ElementsWarm-up

1. Pick up the chemistry pretest2. Turn in your signed syllabus and lab safety forms

if you have them3. Pick up your name tag and head to your assigned

seat4. If you were not in class the first day come see

Mr. Burkhead!5. We will spend approximately 40 minutes on the

pretest, no need to guess if you don’t know the answers

6. Last half of class we’ll start the periodic table scavenger hunt

Day 2 – Meet the ElementsKey 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!


Warm-up 9/1 and 9/2Chemistry 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!


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


Unit Vocabulary (Chapter 1 and 2)Chemical change AtomPhysical change Change of stateExtensive property Significant figuresIntensive property Scientific notationCompound AccuracyElement PrecisionMixture 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 MeasurementWarm-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.


Learning Target #1

Categorize matter as elements, compounds, heterogeneous mixtures, or homogeneous mixtures.


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.


A mixture is a blend of two or more pure substances that retain their own identities and properties.

Example: air, blood, salt water, soil


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.


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


Each colored sphere represents one kind of atom

Atomic level view of elements, compounds, and mixtures



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!


Learning Target #2

Identify and distinguish different properties and changes of matter


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.


Phase changes are often confused as chemical changes but the substances do NOT change identity.


http://vital.cs.ohiou.edu/steamwebsite/downloads/ChangeLab.swf





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


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.


Warm-up 9/10 and 9/14

Pick up and complete “Hypothesis Worksheet”


Learning Target #3

Utilize SI units, significant figures, and scientific notation


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 = candelaTemperature = Kelvin (K)

Other units can be derived from these base seven units.


SI Units may use metric prefixes to make larger and smaller numbers more convenient.


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.



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?



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


Significant figures consist of every digit that has been measured plus one more digit that has been estimated.


Matter and MeasurementWarm-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 MeasurementWarm-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


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

https://www.youtube.com/watch?v=0fKBhvDjuy0


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.



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.





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)



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


Learning Target #4

Perform unit conversions using dimensional analysis.


Dimensional analysis

A systematic approach to solving calculations using units and conversion factors.


Matter and MeasurementExample!How many seconds in a day?

Step 1: Determine the known (given) and unknown (what you’re solving for)

Matter and MeasurementHow 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


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 1: Determine the known (given) and unknown (what you’re solving for)Step 2: Write needed conversion factors = to 1Step 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)


Step 1: Determine the known (given) and unknown (what you’re solving for)Step 2: Write needed conversion factors = to 1Step 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!



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?



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.



Extra Practice

1. Click on the link below http://nursing.flinders.edu.au/students/studyaids/drugcalculations/page.php?id=1

2. Click on Quiz 2: Converting Metric Units

http://nursing.flinders.edu.au/students/studyaids/drugcalculations/page.php?id=1





1. Pick up lab sheets2. Read “Beverage Density Lab”3. Make a guess, which beverage contains the

most sugar? Record in your notebook.


Learning Target #5

Determine the density of a substance experimentally.


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?


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 liquid4. Subtract the mass of the graduated cylinder5. Divide the mass by the volume (10.0 mL) to get

the density and record



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?

Documents

Day 2 – Meet the Elements Warm-up 1.Pick up the chemistry pretest 2.Turn in your signed syllabus and lab safety forms if you have them 3.Pick up your name