1st Nine Weeks Test Study Guide Answers

1. Solubility – the ability of one material to dissolve in another material; can be used to separate solutions ex. Sugar/sand/water 2. Thermal conductors – material through which thermal energy flows easily ex. metals 3. Thermal insulators – material through which thermal energy flows slowly ex. Cloth; winter coat 4. Specific heat – amount of thermal energy needed to raise the temperature of 1kg of material 1 degrees Celsius

5. Thermal expansion – an increase in a material’s volume when temperature is increased ex. Hot air balloon 6. Thermal contraction – a decrease in a material’s volume when temperature is decreased 7. Thermostat – a device that regulates temperature of a system 8. Bimetallic coil – used in a thermostat to regulate temperature; made of two types of metals that expand and contract at different rates

9. Convection current – movement of fluids in a cycle because of convection 10. Heating appliance and examples – device that converts electric energy into thermal energy ex. Curling iron, toaster, oven 11. Conduction – transfer of thermal energy due to collisions between particles 12. Radiation – energy carried by electromagnetic waves ex. Sun rays

13. Convection – circulation of particles within a material caused by differences in thermal energy and density 14. Heat – the movement of thermal energy from a region of higher temperature to a region of lower temperature 15. Thermal energy – sum of the kinetic and potential energy of the particles that make up an object 16. Kinetic energy – energy due to motion

17. Potential energy – stored energy due to the interaction between two objects 18. Temperature – measure of the average kinetic energy of the particles in a material 19. Conductivity – the ability or power to conduct or transmit heat, electricity, or sound 20. Law of conservation of mass – mass is neither created nor destroyed. In a closed system, mass of reactants is equal to mass of products.

21. How does heating occur? when thermal energy is transferred from a warmer object to a cooler object 22. How is energy transferred in a heat engine? chemical energy (gas) > thermal energy ( combustion) > mechanical energy (motor runs and car moves) 23. What is the formula for calculating volume? V = LWH 24. What is the difference between chemical and physical properties? chemical property – ability or inability of a substance to combine with or change into a new substance physical property – characteristic you can observe using your senses without changing the material

25. What are signs of a chemical change 25. What are signs of a chemical change? color change, formation of a gas, smoke or precipitate, light, or heat 26. List examples of physical properties (and changes) Physical properties – color, mass, density, volume, solubility, melting/boiling point Physical changes – dissolving, changing size, shape, form or state 27. How does temperature effect the state of matter of water? As temperature increases, water changes from a solid > liquid > gas, it changes its state of the matter.

28. List the steps of the design process in order. Identify the Problem or need Research the problem and brainstorm solutions Design solutions Construct a prototype Test & Evaluate Redesign Communicate results 29. What is the difference between scientific theories and laws? laws are always true 30. How does a refrigerator work? coolant is used to move thermal energy from inside (cooler location) to the outside of the fridge (warmer location)