Chemistry Vocabulary

2. the basic unit of a chemical element
4. an extremely tiny particle with a positive charge; is in the center of the atom and makes up the nucleus
7. the mass of an atom of a chemical element expressed in atomic mass units
8. a heterogenous mixture in which some of the particles settle out of the mixture upon standing
13. a energy level defined by quantum theory
14. a diagram that represents the variation of a variable
16. where electrons are likely to be found
19. a combination of two or more substances
22. a variable that depends on other factors
25. a pure substance that is made up of two or more different elements combined by chemical bonds
26. a simple way of writing down the locations of all the electrons in an atom
29. in the center of the atom with the protons making up the nucleus
33. the number of digits in a value
35. the energy required to remove an electron from an atom
36. electrons in the outermost shell
37. a physical substance
38. the tendency of an atom to attract an electron to itself
39. any of two or more forms of a chemical element

1. a positively charged ion
3. a model presented by niels bohr and ernest rutherford in 1913
5. a row of elements in the periodic table
6. a variable that stands alone
7. a negatively charged ion
9. a process for experimentation that is used to explore observations and answer questions
10. the number of protons in the nucleus of an atom
11. a type of matter that has definite chemical and physical properties
12. a group of atoms bonded together
13. physically combined; can be separated
15. a negative charge that surrounds the nucleus
17. objects, events, ideas, feelings, time periods, or any other types of categories that you are trying to measure
18. heterogenous, even though it looks homogenous
20. a pure substance that contains of only one kind of atom
21. a way of representing atoms or molecules as dots surrounding the element symbols
23. a table of chemical elements arranged in order of atomic number
24. the central part of the atom; contains protons and neutrons
27. fixed distances from the nucleus of an atom where electrons may be found
28. the size of a neutral atom
30. specific patterns that are presented in the periodic table
31. the number of protons minus the number of electrons
32. a column of elements in the periodic table
34. the chemical element in group 18 of the periodic table