chemistry

6. a vertical column of elements in the periodic table- can show number of valence electrons.
7. a group of two or more atoms held together by chemical bonds.
9. Change a change in matter that cannot be reversed and results in a new substance being formed; signs of chemical change include gas production (bubbles), color change, temperature change, and/or precipitate forms.
11. in a solution, the substance that dissolves.
13. an element that has physical and chemical properties of both metals and nonmetals; can be a semi-conductor.
15. a homogeneous mixture in which one substance completely dissolves in another substance.
16. hard substance that will break or shatter easily.
18. elements classified by physical properties that include shininess, malleability, ductility and conductivity.
21. the smallest component of an element having the chemical properties of the element; smallest unit of matter
23. Mass total mass of the protons and neutrons in an atom, measured in atomic mass units; number of protons + neutrons
25. Number the number of protons in the nucleus of an atom.
26. the elements or compounds produced by a chemical reaction.
27. a solid that forms during a chemical reaction that takes place in a solution.

1. Mixture a mixture in which substances are not distributed evenly. (You can see the different parts)
2. a horizontal row of elements in the periodic table- shows number of electron shells for an element.
3. Mixture a mixture in which substances are distributed evenly. (You cannot see the different parts)
4. Change a change in matter that usually can be reversed such as size, shape, or state.
5. a substance that is present at the beginning of a chemical reaction.
8. the tendency of a substance to undergo chemical changes.
10. used to describe a material that can be hammered or beaten into thin sheets.
12. in a solution, the substance that does the dissolving.
14. an element that usually is a gas or brittle solid at room temperature, is not malleable or ductile, is a poor conductor of heat and electricity, and typically is dull.
17. of Conservation of Mass the scientific principle that matter is neither created nor destroyed during a chemical change.
19. a pure substance that is made up of only one kind of atom
20. the ability of a substance to be pulled into a wire.
22. a combination of two or more substances that are not chemically combined.
24. a pure substance that forms when two or more elements are held together by a chemical bond; Every molecule of a compound is the same.
28. an atom that has lost or gained an electrons and therefore has an electrical charge.