1. Control A sample that is treated like the other experimental groups except that the independent variable is not applied to it.

2. Variable Factor that can be changed in an experiment Independent The variable that is changed Dependent The factor being measured

3. Independent Variable The variable that YOU change in the experiment 50 mL water100 mL water200 mL water

4. Dependent Variable The variable that responds to the independent variable What changes because YOU changed something 50 mL 100 mL 200 mL Height of Plant = (affects)

5. Mixture Two or more substances put together that can be easily separated.

6. Solution A mixture of two or more substances dissolved to form one substance (difficult to separate).

7. Physical Property A characteristic that can be observed or measured Shiny Red Soft Box = 9 cm long

8. Density Describes how much matter is packed into a given space More DenseLess Dense

9. Physical Change Change in which only the physical properties change, you still have the same substance breaking a pencildissolving sugar in water

10. Chemical Property Describes how a substance will react with other substances A bike left out in the rain can rust. Paper is flammable. (it can burn)

11. Chemical Change Change in which new substances form that have different properties from the original substances Rusting Metal Chain Burning match produces smoke and ash

12. Element a pure substance that is made entirely from one type of atom

13. Smallest part of matterSmallest part of matter Made of protons, neutrons, and electronsMade of protons, neutrons, and electrons Non-livingNon-living ATOM

14. form when two or more atoms join together chemically MOLECULE H O H HH H2H2H2H2 H2OH2OH2OH2O

15. COMPOUND a molecule that contains at least two different elements All compounds are molecules but not all molecules are compounds! H O H HH H2H2H2H2 H2OH2OH2OH2O

16. ATOMIC # the number of protons on the nucleus

17. ATOMIC MASS/MASS # # of Protons + # of Neutrons

18. SUB-ATOMIC PARTICLES PROTON+INSIDENUCLEUS NEUTRON0 INSIDE NUCLEUS ELECTRON- OUTSIDE NUCLEUS

19. FAMILY/GROUP = COLUMNS elements have similar propertieselements have similar properties the elements in a group have the same number of electrons in their outer orbitalthe elements in a group have the same number of electrons in their outer orbital *some exceptions in the transition metals

20. PERIODS = ROWS Elements have the same number of atomic orbitals in a period