Force of Electricity

1. What factors determine the
strength of electric forces?

Essential Questions:

What are ATOMS?

•Positive and negative charges
begin with the atom.
•Protons - positive charge
•Electrons – negative charge
•If the number of protons and
electrons is the same, the atom
has no charge or is neutral.
•Atoms tend to gain and lose
electrons easily.

Electric and Magnetic Forces

Atoms (cont.)

•Gain of electrons = negative
charge
•Loss of electrons = positive
charge
•A charged atom is an ion.
•Because this atom is now
positive, it will be attracted and
bond to an atom with a
negative charge. (opposites
attract)

Electric and Magnetic Forces

7P

Loses an electron

Positive Ion

What are electrical forces?

•Electric Forces – occur when ions
create attractive and repulsive
forces

•Electromagnetism – a force
combining both electric and
magnetic forces

Electric and Magnetic Forces

Magnetic Force

Electric Force

Electric Forces

•Electric charges create electric forces.
•Like magnets, there are two
types of charges – positive and
negative.
•Like magnets, the forces either
attract or repel.
•This is called static electricity,
which does not move through
a current.

Electric and Magnetic Forces

When you rub the balloon on your hair,
you removed electrons giving the
balloons a negative “charge”. The
balloons are now “attracted” to your
positively charge hair.

Electric and Magnetic Forces

What is electrical current?

•Rate of flow of charged particles
•Electric charge is made up of
protons (+) and electrons (–)
•When electrons flow in a circuit,
a current is produced.
•Measured in Amperes (A)

•1A = 1,000 mA milliamperes
•1mA = 0.001 A

Ammeter – measures
the current in a circuit

Electric and Magnetic Forces

What is a circuit?

The energy source (battery)
gives energy to electrons and
pushes them around a circuit
from the negative (-) terminal to
the positive (+) terminal of the
cell.

B – Battery

L1 and L2 – Lights

S - Switch

How do Electrons Flow?

Electron flow

-
B

S

Quick Action – Electric and Magnetic
Forces

What are differences between static and current electricity?

Electron
flow

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