Chemistry Midterm

4. A negatively charged, fast-moving particle
6. The extremely small, positively charged, dense center of an atom
7. A neutral, subatomic particle in an atom’s nucleus
8. Describes a relationship in nature that is supported by many experiments
9. A highly reactive group 17 element
12. A tentative, testable, statement or prediction about what has been observed
13. The sum of protons and neutrons
16. A transition of matter from one state to another
18. Electrons on the outermost energy level
21. The amount of heat required to raise the temperature of a given substance by one degree Celsius
22. An explanation supported by many experiments
23. A subatomic particle in an atom’s nucleus that has a positive charge

1. A 3-d region around the nucleus
2. The amount of mass per unit volume
3. A vertical column of elements in the periodic table arranged in order of increasing atomic number
5. Group 1 elements
7. An extremely unreactive group 18 element
10. Gaseous state of a substance that is a liquid or a solid at room temperature
11. The SI unit of heat and energy
14. A pure substance that cannot be broken down into simpler substances
15. Atoms of the same element with different numbers of neutrons
17. The smallest particle of an element
19. The study of matter and the changes it undergoes
20. A horizontal row of elements in the modern periodic table