What are the 2 changes undergone by matter?
Matter can undergo changes of two basic types: physical changes and chemical changes. Physical changes are processes in which a material changes its physical appearance but not its basic identity. The evaporation of water is a physical change.
What properties are used to describe matter?
Physical properties are used to observe and describe matter. Physical properties include: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity, and many others.
What tests were used to identify unknown substances?
The tests that were done to determine the identity of the compound include qualitative solubility tests, quantitative solubility tests, measuring solution conductivity, anion and cation test, flame test, and formation of precipitate.
What is an unknown sample in forensics?
Unknown/questioned sample – evidence of unknown origin; these samples could be found at a crime scene, transferred to an offender during commission of a crime, or recovered from more than one crime scene.
What other places may be considered part of the crime scene?
A crime scene is any physical scene, anywhere, that may provide potential evidence to an investigator. It may include a person’s body, any type of building, vehicles, places in the open air or objects found at those locations.
What are the 5 types of impression evidence?
- Types Impression Evidence.
- Shoe Impressions.
- Historical Case.
- Use Caution.
- Preservation and Documentation.
- Tire Impressions.
- Glove Prints.
- Tool Mark Impressions.
What is an example of impression evidence?
Impressions are created when one object is pressed against another material with enough force to leave an impression of the object. Shoeprints, tool marks, tire tracks, bite marks, and marks on a fired bullet are several examples of impression evidence.