The Baby and the Bottle
A child is brought to the emergency room unconscious. The doctor is concerned that the child has been poisoned, possibly by the contents of his bottle. This problem-based unit asks students to complete a series of experiments to determine whether the boy’s bottle contains something besides water.
This problem-based unit was designed to teach the required objectives for properties of matter in the state of Texas. It would likely work with or without modification in many other venues. The student is expected to:
(A) differentiate between physical and chemical changes and properties;
(B) identify extensive and intensive properties;
(C) compare solids, liquids, and gases in terms of compressibility, structure, shape, and volume;
(D) classify matter as pure substances or mixtures through investigation of their properties.
Teacher instructions and keys are included for each activity.
- Introduction…Students read and discuss the case.
- Extrinsic and Intrinsic Properties…Students observe the intrinsic and extrinsic properties of the liquid in the bottle to determine if the bottle’s liquid is “pure” water. Vocabulary: extrinsic properties, intrinsic properties
- Separating a Mixture…Students practice separating several mixtures before deciding on the procedure they want to follow to separate the mixture in the bottle. Vocabulary: pure substance, element, compound, mixture, homogeneous mixture, heterogeneous mixture. (A supplemental section - to occupy students during slow lab processes - discusses the states of matter.)
- Physical and Chemical Changes …Students compare the solid isolated from the bottle to known solids from the child’s house to determine if there is a match. Vocabulary: physical properties, chemical properties, physical changes, chemical changes
- Making a Case…Students evaluate the case file to decide if charges should be filed against anyone for the boy’s sickness.
See the Preview for a list of materials, timing, the Introduction, and the Physical and Chemical Properties component.