Electron Affinity How much does a material love electrons? Which had greater electron affinity? – Plastic rod & animal fur Plastic rod – Glass rod & animal fur Animal fur

Big Ideas #1: Like charges repel. #2: An object becomes negatively charged when it gains electrons, so that it has more electrons than protons. #3: An object becomes positively charged when it loses electrons, so that it has fewer electrons than protons. #4: Oppositely charged objects attract.

Electroscope Make note of the following in your notebook: What do you observe when you place a charged plastic rod… a)Near the top of the electroscope? Then pulled away from the electroscope? b) On top of the electroscope? Then pulled away from the electroscope?

Electroscope Make note of the following in your notebook: What do you observe when I place a charged metal tin… a)Near the top of the electroscope? Then pulled away from the electroscope? b) On top of the electroscope? Then pulled away from the electroscope?

Big Ideas #5: Conductors allow electrons to flow through object and are easily removed/gained. #6: Insulators do NOT allow electrons to move easily through object and are NOT easily removed/gained.

Charged Rod and Aluminum Soda Can

Charged Rod and Plastic Water Bottle

Draw particle pictures for the metal can and plastic rod when they are brought near AND the plastic bottle and plastic rod when they are brought near. Remember there is no CONTACT! Make sure that your picture distinguishes between what is happening in the metal (conductor) and the plastic (insulator).

Big Ideas #7: Polarization is when an object’s electrons are shifted so that one part of the object is “more negative ” and another region is “ more positive.”