Chemistry

2. he used a cathode ray tube to discover the presence of electrons, and proposed the plum pudding model of an atom
7. electrons in the outermost energy level
8. two or more pure substances together but are not chemically combined
10. the name of a horizontal row on the period table
11. a ______________ mixture is two or more substances that cannot be identified as separate because the composition is uniform
12. the type of bond where electrons are transferred between atoms
13. the charge of an electron
14. the type of bond where electrons are shared between atoms
20. a pure substance made of only one type of atom
21. the charge of a proton
22. the number of shells in a neutral calcium atom
24. an element that is a poor conductor of electricity, brittle, and a gas at room temperature
26. a negatively charged ion
27. same atom with different numbers of neutrons, which gives it a different mass
29. a positively charged ion

1. name of the ionic compound NaCl
3. any material that has mass and volume
4. a negatively charged sub-atomic particle found around the nucleus
5. the name of a vertical column on the periodic table
6. a pure substance made of more than one type of atom that is chemically combined
9. a charged atom
15. the smallest unit of matter, made of protons, neutrons and electrons
16. an uncharged sub-atomic particle found in the nucleus
17. he used the gold foil experiment to identify the presence of the nucleus
18. a ______________ mixture of two or more substances, but you can identify the parts of the mixture
19. the number of electrons that can fit in the first shell
21. a positively charged sub-atomic particle found in the nucleus
23. the term we use to describe what matter is made of
25. an element that is a good conductor of electricity, malleable, and typically solid at room temperature
28. the ___________ rule states the number of electrons in the outmost should be 8 to fill the energy level