7. You are handed two mystery materials and told to determine which one accepts negative charges more easily. Using a positively charged, helium-filled balloon that is
tied to a tabletop with a 1 m long string, describe a simple experiment that will help you
identify the more attractive material.

Which type of bond is found between the atoms of a molecule? a. metallic b. delocalized electron c. covalent d. ionic

The focal length of a relaxed human eye is approximately 1.7 cm. when we focus our eyes on a close up object, we can change the refractive power of the eye by about 16 diopters. (a) does the refractive power of our eyes increase or decrease by 16 diopters when we focus closely? explain. (b) calculate the focal length of the eye when we focus closely.

Which is not true of the intertropical convergence zone? a) it features heavy precipitation b) it's where the trade winds collidec) it's a high-pressure zone with sinking air d) it is also known as the doldrums