Grade: Grade 5 Subject: Science Unit: Matter & Properties SAT: ProblemSolving+DataAnalysis ACT: Science

Investigation Lab: Exploring Matter

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What is a Scientific Investigation?

A scientific investigation is a process scientists use to explore questions about the natural world. When studying matter, we conduct investigations to observe and measure physical and chemical properties. Good investigations follow careful procedures, collect accurate data, and lead to evidence-based conclusions.

Lab Safety Rules

  • Always wear safety goggles when working with liquids or chemicals
  • Never taste any substances unless specifically instructed by a teacher
  • Handle hot objects with care using proper tools
  • Clean up spills immediately and report any accidents
  • Wash hands thoroughly after completing experiments
  • Follow all instructions carefully - ask questions if unsure

Investigation Stations

Explore these hands-on investigations to observe properties of matter.

1

Density Discovery

Investigate why some objects float and others sink by calculating density.

Materials
  • Balance scale
  • Graduated cylinder with water
  • Various objects (marble, cork, penny, rubber ball)
  • Calculator
Procedure
  1. Measure the mass of each object using the balance
  2. Record the initial water level in the graduated cylinder
  3. Gently lower each object into the water
  4. Record the new water level (this change equals volume)
  5. Calculate density: mass divided by volume
  6. Predict which objects will float (density less than 1 g/mL)
2

Solubility Test

Investigate which substances dissolve in water and which do not.

Materials
  • 6 clear cups with 100mL water each
  • Salt, sugar, sand, oil, baking soda, flour
  • Spoons for stirring
  • Stopwatch
Procedure
  1. Add one teaspoon of each substance to separate cups
  2. Stir each mixture for 30 seconds
  3. Observe and record what happens
  4. Note which substances dissolve completely
  5. Record which substances remain visible
  6. Classify each as soluble or insoluble
3

Chemical Change Indicators

Observe signs of chemical changes using safe household substances.

Materials
  • Baking soda
  • Vinegar
  • Clear container
  • Steel wool and water
  • Observation journal
Procedure
  1. Add 2 tablespoons of baking soda to the container
  2. Slowly pour vinegar and observe the reaction
  3. Record all signs of chemical change you observe
  4. In a separate area, place wet steel wool
  5. Check the steel wool over several days
  6. Document the color changes as rust forms
4

States of Matter Observation

Observe water in different states and document particle behavior.

Materials
  • Ice cubes
  • Hot plate (teacher supervised)
  • Beaker
  • Thermometer
  • Timer
Procedure
  1. Place ice in the beaker and record the temperature
  2. Allow ice to melt at room temperature
  3. Record temperature every 2 minutes
  4. With teacher help, heat the water gently
  5. Observe steam rising as water boils
  6. Document temperature at each state change
Scientist Tip: Always record your observations exactly as you see them, even if the results are unexpected. Unexpected results often lead to important discoveries!

Examples

Virtual Density Lab

Calculate Object Density

Before: 50 mL
After: ? mL

Object: Mystery Marble

Mass (measured on balance): 25 g
Volume (water displacement): Click Measure
Density (mass / volume): ?
Will it float in water? ?

Sample Data Table

Object Mass (g) Volume (mL) Density (g/mL) Float or Sink?
Cork 3 12 0.25 Float
Penny 2.5 0.35 7.14 Sink
Rubber Ball 45 65 0.69 Float
Marble 5 2 2.5 Sink
Key Insight: Objects with density less than 1 g/mL float in water. Objects with density greater than 1 g/mL sink. Water has a density of exactly 1 g/mL!

Practice

Apply what you learned about scientific investigations.

Question 1: A student measures an object with a mass of 30 grams. When placed in water, the water level rises from 50 mL to 60 mL. What is the object's density?

A) 0.33 g/mL
B) 30 g/mL
C) 3 g/mL
D) 10 g/mL

Question 2: Which safety practice is MOST important when working with unknown liquids?

A) Wearing safety goggles at all times
B) Working as quickly as possible
C) Tasting a small amount to identify it
D) Mixing different liquids together

Question 3: A student tests whether salt dissolves in water. The salt disappears completely. What should the student conclude?

A) The salt was destroyed
B) Salt is soluble in water
C) A chemical change occurred
D) The experiment failed

Question 4: When measuring volume using water displacement, why is it important to read the water level at eye level?

A) To see the object better
B) To stay safe during the experiment
C) To get an accurate measurement without parallax error
D) To avoid spilling water

Question 5: An object has a density of 0.8 g/mL. What will happen when it is placed in water?

A) It will float
B) It will sink
C) It will dissolve
D) It will evaporate

Question 6: During an investigation, bubbles form when two substances are mixed. This is evidence of:

A) A physical change only
B) A chemical change producing gas
C) The substances dissolving
D) Water evaporating

Question 7: What is the purpose of recording data in a table during an investigation?

A) To make the experiment look more professional
B) To organize observations and identify patterns
C) To use up extra paper
D) To copy what other scientists have found

Question 8: A student observes that steel wool turns from gray to orange-brown over several days when kept wet. What type of change is occurring?

A) Physical change - the steel wool is drying out
B) Chemical change - iron is reacting with oxygen to form rust
C) Physical change - the steel wool is melting
D) No change is occurring

Check Your Understanding

Investigation Reflection Questions

  1. Why is it important to measure both mass AND volume to calculate density?
  2. How can you tell if a change during an experiment is physical or chemical?
  3. What should you do if your experimental results are different from what you predicted?
  4. Why do scientists repeat experiments multiple times?
Remember: The scientific method is a cycle. After drawing conclusions, scientists often ask new questions and design new investigations!

Summary

🔬

Investigation

A process to explore questions through observation and measurement

📊

Data Collection

Recording observations accurately in organized tables

⚗️

Density

Mass divided by volume; determines floating/sinking

🛡️

Safety First

Always follow lab safety rules and procedures

Next Steps

  • Complete your lab notebook with all observations
  • Practice calculating density with different objects at home
  • Continue to learn about data analysis and graphing