ALEX Classroom Resource

  

Temperature Affects Density

  Classroom Resource Information  

Title:

 Temperature Affects Density

URL:

 https://www.middleschoolchemistry.com/lessonplans/chapter3/lesson6

Content Source:

 Other
American Chemical Society
Type: Lesson/Unit Plan

Overview:

In this lesson, students place hot and cold colored water into room-temperature water. They observe that the hot water floats on the room-temperature water and the cold water sinks. Students will combine the concepts of temperature, molecular motion, and density to learn that hot water is less dense than room-temperature water and that cold water is denser.

Students will be able to explain, on the molecular level, how heating and cooling affect the density of water.

Content Standard(s):
Science
SC2015 (2015)
Grade: 8
Physical Science
4 ) Design and conduct an experiment to determine changes in particle motion, temperature, and state of a pure substance when thermal energy is added to or removed from a system.

NAEP Framework
NAEP Statement::
P12.5: Changes of state require a transfer of energy. Water has a very high specific heat, meaning it can absorb a large amount of energy while producing only small changes in temperature.‡

NAEP Statement::
P12.8: Atoms and molecules that compose matter are in constant motion (translational, rotational, or vibrational).

NAEP Statement::
P8.1: Properties of solids, liquids, and gases are explained by a model of matter that is composed of tiny particles in motion.

NAEP Statement::
P8.6a: Changes of state are explained by a model of matter composed of tiny particles that are in motion.

NAEP Statement::
P8.6b: When substances undergo changes of state, neither atoms nor molecules themselves are changed in structure.

NAEP Statement::
P8.6c: Mass is conserved when substances undergo changes of state.

Unpacked Content
Scientific And Engineering Practices:
Planning and Carrying out Investigations
Crosscutting Concepts: Systems and System Models
Disciplinary Core Idea: Matter and Its Interactions
Evidence Of Student Attainment:
Students:
  • Design an experiment to determine changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed from a system.
  • Conduct an experiment to determine changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed from a system.
Teacher Vocabulary:
  • Particle motion
  • Temperature
  • State [of Matter]
  • Pure substance
  • Thermal Energy
  • Kinetic Energy
  • System
Knowledge:
Students know:
  • Changes in particle motion of a pure substance occur when thermal energy is added to or removed from a system.
  • Changes in temperature of a pure substance occur when thermal energy is added to or removed from a system.
  • Changes in state of a pure substance occur when thermal energy is added to or removed from a system.
Skills:
Students are able to:
  • Identify the phenomena under investigation, which includes changes in particle motion, temperature, and state of a pure substance when thermal energy is added to or removed from a system.
  • Identify the purpose of the investigation, which includes determining changes in particle motion, temperature, and state of a pure substance when thermal energy is added to or removed from a system.
  • Develop a plan for the investigation individually or collaboratively.
  • Describe factors used in the investigation including appropriate units (if necessary), independent and dependent variables, controls and number of trials for each experimental condition.
  • Perform the investigation as prescribed by the plan.
  • Use data from the investigation to provide an causal account of the relationship between the addition of removal of thermal energy from a substance and the change in the average kinetic energy of the particles in a substance.
Understanding:
Students understand that:
  • Adding or removing thermal energy from a system causes changes in particle motion of a pure substance.
  • Adding or removing thermal energy from a system causes changes in temperature of a pure substance.
  • Adding or removing thermal energy from a system causes changes in state of a pure substance.
AMSTI Resources:
AMSTI Module:
Exploring the Properties of Matter
Alabama Alternate Achievement Standards
AAS Standard:
SCI.AAS.8.4- Recognize that changes in temperature can cause changes in the state of matter of a substance; recognize that these changes are a result of changes in particle motion.
Science
SC2015 (2015)
Grade: 8
Physical Science
5 ) Observe and analyze characteristic properties of substances (e.g., odor, density, solubility, flammability, melting point, boiling point) before and after the substances combine to determine if a chemical reaction has occurred.

NAEP Framework
NAEP Statement::
P8.2: Chemical properties of substances are explained by the arrangement of atoms and molecules.

NAEP Statement::
P8.7a: Chemical changes can occur when two substances, elements, or compounds react and produce one or more different substances whose physical and chemical properties are different from the reacting substances.

Unpacked Content
Scientific And Engineering Practices:
Analyzing and Interpreting Data
Crosscutting Concepts: Patterns
Disciplinary Core Idea: Matter and Its Interactions
Evidence Of Student Attainment:
Students:
  • Observe characteristic properties of substances before and after the substances combine.
  • Analyze characteristic properties of substances before and after the substances combine.
  • Determine if chemical reactions have occurred based on observations and analysis of the characteristic properties of substances before and after the substances combined.
Teacher Vocabulary:
  • Characteristic properties (e.g., odor, density, solubility, flammability, melting point, boiling point)
  • Substances
  • Chemical reaction
Knowledge:
Students know:
  • Each pure substance has characteristic physical and chemical properties that can be used to identify it.
  • Characteristic properties of substances may include odor, density, solubility, flammability, melting point, and boiling point.
  • Chemical reactions change characteristic properties of substances.
  • Substances react chemically in characteristic ways.
  • In a chemical process, the atoms that make up the original substances are regrouped into different molecules, and these new substances have different properties from those of the reactants.
Skills:
Students are able to:
  • Observe characteristic physical and chemical properties of pure substances before and after they interact.
  • Analyze characteristic physical and chemical properties of pure substances before and after they interact.
  • Analyze the properties to identify patterns (i.e., similarities and differences), including the changes in physical and chemical properties of each substance before and after the interaction.
  • Use the analysis to determine whether a chemical reaction has occurred.
Understanding:
Students understand that:
  • Observations and analyses can be used to determine whether a chemical reaction has occurred.
  • The change in properties of substances is related to the rearrangement of atoms in the reactants and products in a chemical reaction (e.g., when a reaction has occurred, atoms from the substances present before the interaction must have been rearranged into new configurations, resulting in the properties of new substances).
AMSTI Resources:
AMSTI Module:
Exploring the Properties of Matter
Experimenting with Mixtures, Compounds, and Elements
Alabama Alternate Achievement Standards
AAS Standard:
SCI.AAS.8.5- Compare the properties of substances (color, texture, odor, state of matter) before and after chemical changes have occurred (e.g. burning sugar, burning steel wool, rust, effervescent tablets).
Tags: dense, density, experiment, mass, molecular motion, substance, temperature, thermal energy, volume
License Type: Custom Permission Type
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AccessibilityVideo resources: includes closed captioning or subtitles
Comments

A video that explains how to teach the lesson is provided.

  This resource provided by:  
Author: Stephanie Carver