16. Transfer of heat from one place to another through liquid ___________________
17. The travel of heat in solid materials ___________________
18. Transfer of heat through empty spaces ___________________
19. Materials that doesn’t allow heat to pass through ___________________
20. The heat we receive from the sun ___________________
21. The movement of an object back and forth ___________________
22. The bending of light as it travels from one material to another ___________________
23. The bouncing back of light as it strikes in a smooth surface ___________________

conductors convection vibration insulators radiant energy refraction radiation reflection conduction