Lesson seven
What is a chemical reaction? Science Grade 8
C o ns tr u ct in g E x p la na tio n s , E n ga g in g in A r g u m e nt a nd O bt a in in g , E v a lu a t in g, a nd C om m u n ica tin g I nf or m a t ion ENGLISH LANGUAGE ARTS 90 minutes R e a d in g I nf or m a t ion a l T e x t , W ri t in g a n E x p la na t io n PURPOSE
In this lesson, students learn about the process of chemical reactions, setting a foundation for
subsequent lessons. Students formulate conjectures about chemical reactions and gather information
from text to revise these conjectures. Students work with their peers to revise and document these
developing understandings.
STANDARDS
C o m m o n C o r e S ta te S ta n d a rd s
•
D e v e l op th e to p ic w it h r e le v a n t, w e l l-­ ch o s e n f a c ts , de f i n it io n s , c on c re te d e t a i ls , q u ot a t i on s , or o t h e r i nf o r m a t i on a n d e x a m pl e s. C C S S .E L A -­
L IT E R A C Y . W H S T . 6 -­8 . 2. B •
U s e p re c is e l a n g ua ge a n d d o m a in -­ s p ec if i c v oc a b ul a r y to in f o r m a bo u t o r e x p la in t h e t o pic . C C S S . E L A -­ L IT E R A C Y . W H S T . 6 -­ 8 . 2. D •
G a th e r r e le v a nt i nf o r m a ti on f ro m m ul tip le pr in t a n d d ig it a l s ou r ce s , u s in g s e a r ch t e rm s e f f e c tiv e ly ; a s s e ss th e c re d ib il ity a n d a cc ur a c y o f e a c h s ou r ce ; a n d q u ot e o r p a r a p h ra se th e d a ta a n d c on cl us io n s o f oth e r s w h il e a v oid in g p la g ia ri sm a n d f oll ow in g a s t a n d a r d f o rm a t f o r cit a t i on . C C S S .E L A -­ L IT E R A C Y . W H S T . 6-­ 8 . 8 •
D r a w e v i de n ce f r om in f o rm a tio n a l te x ts t o s up p or t a n a ly s is , r e f l e ctio n , a n d r e s e a r ch . C C S S . E L A-­ L IT E R A C Y . W H S T . 6 -­ 8 . 9 Lesson SEVEN
W h a t i s a ch em ic a l r e a ct io n ?
Formative Assessment
Lesson Plans
STANDARDS Continued
C o m m o n C o r e S ta te S ta n d a rd s
•
D e l in e a te a s pe a ke r ' s a rg u m e nt a nd s pe c if ic c la i m s, e v a lu a ti ng th e s ou n d ne s s of th e re a so n in g a n d r e le v a nc e a nd s uf f ici e nc y of th e e v id e n ce a n d id e n t if y in g w h e n i rr e le v a nt e v i de n ce is in t r od u ce d . C C S S .E L A -­ L IT E R A C Y . S L . 8 .3 N e x t G e n e ra ti o n S c i en c e S ta n d a rd s
•
A n a ly z e a nd in t e r pr e t da t a o n t h e p r op e r t ie s of s u bs t a nc e s b e f o re a n d a f te r th e su b s ta n c es in te r a c t t o d e te rm in e if a ch e m ic a l r e a ct io n h a s o ccu r re d . M S -­ P S-­ 1 -­ 2 •
S t ru ct ur e s a n d Pr o pe r t ie s of M a t t e r. PS 1. A S u b s t a n ce s a r e m a de f r om d if f e r e n t t y p e s o f a t o m s , w h ich co m bi ne w it h o ne a n o t h e r in v a r iou s w a y s . A t o m s f or m m o le cu le s th a t r a n ge in si z e f r om tw o to t ho u sa n ds of a t om s . •
C h e m ica l R e a ct io ns . PS 1. B S u b s t a n ce s re a ct ch e m ic a ll y in c ha ra ct e r is t i c w a y s . I n a ch e m ic a l p ro ce s s , th e a t o m s t ha t m a k e u p t he o rig in a l s u b st a n ce s a r e r e g ro up e d i nt o d if f e r e n t m ole c u le s , a n d t h e s e n e w s ub s t a n c e s h a v e d if f e r e nt p r op e r t ie s f r om th os e of r e a ct a n ts . S c i en c e a n d E n g i n e er i n g P r ac t i c e s •
C o ns tr u ct in g e x p la n a t io ns a n d d e s ig ni n g s olu t ion s •
E n g a g in g in a r gu m e n t f r om e v id e n ce •
O bt a in in g , e v a lu a ti ng , a n d co m m u n ica t in g in f o r m a t i on LEARNING GOALS
Understand that atoms rearrange during a chemical reaction.
Explain the process of a chemical reaction.
2 Lesson SEVEN
W h a t i s a ch em ic a l r e a ct io n ?
Formative Assessment
Lesson Plans
SUCCESS CRITERIA
1
Identify components of chemical reactions (reactants and products).
2
Construct an explanation of chemical reactions.
3
Reference relevant and appropriate evidence to support explanation of the
process of a chemical reaction.
SUMMARY OF LESSON TASKS
1
Record and discuss initial conjectures.
2
Read and annotate: Middle School Chemistry Chapter 6.
3
Complete Double Entry Journal and discuss.
4
Write explanation.
Culminating task
Write a one to two-paragraph explanation in response to the question, “What is a
chemical reaction?” Include information that describes chemical reactions, including
what happens when one takes place. Support your explanation with evidence from
the demonstration, texts, discussions, and other sources. Cite your sources.
PART I: INTRODUCTION
ACTIVATE PRIOR KNOWLEDGE Open the lesson with a connection to what
students have previously learned about atoms and molecules. You may wish to review some
of the charts you created with students in previous lessons.
INTRODUCE THE TOPIC Explain that in today’s lesson, students will explore
what happens to atoms and molecules during a chemical reaction. By the end of the lesson,
students should be able to answer the question: What is a chemical reaction? To begin this
exploration, conduct a short demonstration illustrating a chemical reaction. Ask students to
think about what is happening and encourage them to ask questions while you are
conducting the demonstration. Possible demonstrations: Briggs-Rauscher Oscillating Color
Change Reaction (http://chemistry.about.com/cs/demonstrations/a/aa050204a.htm) or
Formation of Silver Crystals (https://www.youtube.com/watch?v=rgYhkVy5cBU).
3 Lesson SEVEN
W h a t i s a ch em ic a l r e a ct io n ?
Formative Assessment
Lesson Plans
RECORD AND DISCUSS INITIAL CONJECTURES Provide students with
time to construct a Double Entry Journal in their Science Notebooks. In the left-hand
column, students record initial conjectures about the process of chemical reactions, using
their observations and knowledge about atoms and molecules. Students record their
reasoning in the right-hand column of the Double Entry Journal. When students complete
their individual Double Entry Journal, they work in small groups to discuss what they have
observed and compare initial conjectures about what might be happening during a chemical
reaction. Students should record group-level conjecture(s) and prepare to share these with
the whole class. Remind students to select group roles, including recorder and reporter.
Record student contributions in a whole class Double Entry Journal visible to all students.
PART II: guided practice
READ AND ANNOTATE Provide students with a copy of Middle School Chemistry
Chapter 6
(http://www.middleschoolchemistry.com/pdf/chapter6/chapter6_student_reading.pdf).
The text gives information about chemical reactions, including explanations of what these
are and descriptions of what happens when one occurs. Inform students that they will read
pages 680 – 683. Remind them to consider the question, “What is a chemical reaction?” as
they read. At this point students have probably read and annotated several texts and are
ready to do annotate with minimal support. Nonetheless, the text may present specific
challenges for some students. If this is the case, read and annotate the first few paragraphs
of the text together, periodically stopping to discuss the main ideas and supporting details.
After a few sections, allow students to read the remaining text independently.
SUCCESS CRITERION
EVIDENCE-GATHERING OPPORTUNITY
•
Identify main ideas and supporting details.
As students read and annotate the text, gather evidence of learning by
looking at student annotations. Check that students are accurately
identifying the main ideas and supporting details in the text.
4 Lesson SEVEN
W h a t i s a ch em ic a l r e a ct io n ?
Formative Assessment
Lesson Plans
ANTICIPATED RESPONSE
PEDAGOGICAL ACTION
If you notice that students have difficulty identifying main ideas or
supporting details, support students by conducting a guided annotation. You
may choose to first read and annotate one paragraph together. Then, release
responsibility gradually by having students annotate one paragraph on their
own with your support, if needed. Repeat the process, alternating between
teacher-led annotation and independent student annotation with paragraphs
or text sections until students are successful.
COMPLETE DOUBLE ENTRY JOURNAL AND DISCUSS After
students read and annotate text, they work with a partner or two to record main ideas and
supporting details. Each student will construct their own Double Entry Journal in their
Science Notebooks. Pairs or triads should discuss and decide on the main ideas and
supporting details in the text. Students use the Double Entry Journal to organize main ideas
and supporting details in the text, and practice paraphrasing prior to participating in
discussion. Bring the class together and first lead a discussion of the main ideas and
supporting details in the text. Then, discuss the opening question, “What is a chemical
reaction?” Return to the recorded responses at the beginning of the class period and revise
responses using the information from the text.
SUCCESS CRITERION
EVIDENCE-GATHERING OPPORTUNITY
•
Identify and paraphrase main ideas and supporting details.
Gather evidence of learning by checking Double Entry Journals as students
work to paraphrase main ideas and supporting details. During the whole
class discussion, check students’ developing understanding of chemical
reactions. Note the language students use to describe chemical reactions.
Take this opportunity to assess the degree to which students refer to
information from the text or other sources to support their discussion.
5 Lesson SEVEN
W h a t i s a ch em ic a l r e a ct io n ?
Formative Assessment
Lesson Plans
ANTICIPATED RESPONSE
PEDAGOGICAL ACTION
If during discussion you notice that students do not reference the text to
support their responses, you might press for evidence and support by asking
the following questions:
What in the text makes you say that?
• How did you arrive at that conclusion?
•
PART III: culminating task
WRITE EXPLANATION In the final task, students write an explanation that shows
they understand that atoms are not lost but simply rearrange during a chemical reaction. The
explanation includes a description of the process that occurs during a chemical reaction.
Students use information from the text, discussion, and/or demonstration, to support their
explanation. The explanation:
•
•
•
•
provides an accurate description of the process that occurs during a chemical reaction
demonstrates the understanding that atoms rearrange during a chemical reaction
includes appropriate use of key content vocabulary
references relevant and appropriate evidence to support explanation
ADDITIONAL LESSON RESOURCES
B ac kg r ou n d •
Middle School Chemistry Teacher Guide http://www.middleschoolchemistry.com/lessonplans/chapter6/lesson3
6 Lesson SEVEN
W h a t i s a ch em ic a l r e a ct io n ?
Formative Assessment
Lesson Plans
DOUBLE ENTRY JOURNAL: INITIAL CONJECTURES
What is a chemical reaction?
What is your reasoning? 7 Lesson SEVEN
W h a t i s a ch em ic a l r e a ct io n ?
Formative Assessment
Lesson Plans
DOUBLE ENTRY JOURNAL: MIDDLE SCHOOL CHEMISTRY
Main ideas
Supporting details 8