Introduction to Electricity Exploring Static Charges

DEFINITIONS: ELECTRICITY – a form of energy which involves the transfer of electrons STATIC CHARGE – electric charge which tends to stay in one place CHARGING BY FRICTION – creating a static charge by rubbing two objects together. ELECTROSTATIC SERIES – a list of materials that have been arranged according to their tendency to gain or lose electrons.

INSULATOR – a material which holds onto electrons and they cannot move freely CONDUCTOR – a material which lets electrons move freely within it. SEMICONDUCTOR – a materials which can somewhat allows electrons to move freely. GROUND – a materials which can neutralize a substance by either providing electrons or removing them

WHAT CAUSES ELECTRIC CHARGE? The interactions of two neutral objects which results in electrons being transferred from one object to the other. Electrons move because they have limited mass and are not attached to the nucleus.

ELECTROSTATIC SERIES An electrostatic series help us to determine which objects will lose electrons and which ones will gain electrons. From this information we can predict which object becomes negative and which becomes positive, which rubbed together. Objects near the top of the series have a weak hold on electrons and tend to become positive. Objects near the bottom of the series have a strong hold on electrons and tend to become negative. The further apart two objects being rubbed together are on the series, the greater the charge transfer.

What happens when wool is rubbed with foam? What happens when amber is rubbed with glass? What happens when cat fur is rubbed with silk?

HOW DO ANTI-STATIC SHEETS WORK? The sheets contain a waxy compound which gets vaporized from the heat in the dryer. This vapour coats the clothes preventing charges from building up on them, reducing the amount of static.

WHERE DO CHARGES GO WHEN “GROUNDED”? Into the Earth! The Earth has a large capacity to hold electrons, yet still remains a neutral charge.

You body gains an electric charge from walking on the carpet. When you touch the metal doorknob the electrons jump from the knob to your body, resulting in an electric shock.

THE HAZARDS OF STATIC ELECTRICITY Farm workers – grain elevators, coal mines, flour mills Surgeons – cannot wear insulating materials, be careful with pace makers, anaesthetic gases Large moving vehicles – friction between road surface, dust/air particles