Chapter 2 Vocabulary

1. Factual information collected by scientists.
5. Energy associated with motion, such as in flowing water, a speeding car or electricity.
8. Anything that has mass and takes up space. Commonly exists as a solid, liquid, or gas.
10. Energy stored and potentially available for use.
13. Combination of two or more atoms of the same or different elements held together by chemical bonds.
16. Capacity to do work.
17. Numeric value that indicates the relative acidity or alkalinity of a substance on a scale of 0 to 14, with the neutral point at 7.
18. Possible and testable answer to a scientific question or explanation of what scientists have observed in nature.

2. Energy generated and measured by heat.
3. The basic building block of matter.
4. Broad field of study focused on discovering how nature works and using that knowledge to describe what is likely to happen in nature.
6. One of two or more forms of a chemical element that have the same atomic number but different mass numbers because they have different numbers of neutrons in their nuclei.
7. Type of matter with a unique set of properties that cannot be broken down into simpler substances by chemical means.
8. Physical or mathematical representation of a structure or system.
9. Well tested and widely accepted description of observations that have been repeated many times in a variety of conditions.
11. Atom or group of atoms with one or more positive (+) or negative (-) electrical charges.
12. Set of components that function and interact in some regular way.
14. Combination of two or more different elements held together in fixed proportions.
15. Description of what scientist find happening in nature repeatedly in the same way without known exception.