chemistry vocab

1. positively charged particle in the nucleus of an atom.
2. pure substance that cannot be broken down into other substances.
3. the point in temperature that an element starts to boil.
4. elements that has both metallic and nonmetallic properties.
6. orbit of electrons around the nucleus of an atom.
8. cloudy mixture in which tiny particles of one substance are held in another and cannot be separated
10. The smallest part of an element.
12. combination of pure substances; unlike a compound.
13. group 2 elements in the periodic table; not including hydrogen; there reactivity is not as strong as alkaline metals.
15. chemical combination of two or more elements in a specific ratio.
18. group 18 elements in the periodic table; the most stable and unreactive material.
19. a table in which the elements are organized by their physical and chemical properties.
20. shiny, malleable, ductile element that conducts electricity.
21. neutral particle in the nucleus of an atom.

1. a substance that is made of only one kind of matter.
4. heterogeneous mixture; mixture in which the different substances that make up the mixture are visible.
5. change in appearance or state of a substance that does not change composition.
6. invisible negatively charged particle that orbits the nucleus of an atom.
7. cloudy mixture in which tiny particles of one substance are held in another and can be separated.
9. change that results when two or more substances react.
10. mass of one atom of an element calculated from the total number of protons,neutrons, and electrons of that atom; measured in atomic mass units (amu).
11. the point in temperature that an element starts to melt.
14. number of protons in the nucleus of one atom of an element.
16. dull,brittle element that does not conduct electricity.
17. homogeneous mixture; mixture of two or more pure substances that looks like one substance.