Matter Review

2. atomic mass/ the average mass of an element's isotopes, weighted according to the abundance of each isotope
6. a substance that consists of two ore more different elements chemically bonded together
7. a characteristic of matter that you can observe or measure without changing the identity of the matter
11. Said, "Atoms are small solid objects that cannot be divided, created, or destroyed"
12. the sum of protons and neutrons
13. describes elements that spontaneously emit radiation
15. credited with discovering neutrons and that they are neutral
16. a characteristic of matter that can be observed as it changes to a different type of matter
18. discovered electrons
19. a type of mixture that is evenly mixed
21. a change in matter in which the substances that make up the matter change into other substances with new physical and chemical properties
24. any of two or more atoms of the same element that have different numbers of neutrons
26. states that electrons orbit the nucleus
28. an atom that is no longer neutral because it has gained or lost electrons
29. to form a solution by mixing evenly

1. discovered the nucleus
3. the process that occurs when an unstable atomic nucleus changes into another more stable nucleus by emitting radiation
4. states that electrons can be found in the electron cloud
5. an atomic particle with a positive charge
8. the ability of one substance to dissolve in another
9. a neutral particle found in the nucleus of an atom
10. change/ a change in size, shape, form, or state of matter in which the identity stays the same
14. an atomic particle with a negative charge
17. the smallest piece of an element that still represents the element
20. matter with a composition that is always the same
22. mixture/ a type of mixture that is unevenly mixed
23. the number of protons in an atom
25. anything that has mass and takes up space
27. the mass per unit volume of a substance