UNIT 4 ``Heat and Electricity´´

UNIT 4

ELECTRICITY

and

HEAT

ELECTRICAL CIRCUITS

FORMS OF ELECTRICITY

ALL ABOUT CHARGE

ELECTRICITY

EXPANSION

EVAPORATION

MELTING

EFFECTS OF THERMAL ENERGY

CONDUCTORS and INSULATORS

HEAT

PART TWO

PART ONE

SUMMARY

When we heat an object, we add thermal energy. Thermal energy moves from warmer objects to cooler objects. This flow of thermal energy is called heat.

HEAT

PART ONE

Do not transfer heat very well

THERMAL INSULATORS

Transfer heat very well

THERMAL CONDUCTORS

CONDUCTORS and INSULATORS

One of the properties of materials is how well they conduct heat.

When the thermal energy of a substance increases, its volume increases

EXPANSION

EFFECTS OF THERMAL ENERGY

The thermal energy of a liquid increases,and it changes to a gas

EVAPORATION

The thermal energy of a solid increases and it changes to a liquid

MELTING

When we add thermal energy to a substances, there can be a change of state or volume

It is all about charge!

Everything around us is made of ATOMS. But...what is an atom...? The atom is the basic building block for all matter in the universe. Atoms are extremely small and are made up of a few even smaller particles. The basic particles that make up an atom are electrons, protons, and neutrons. Atoms fit together with other atoms to make up matter.

ELECTRICITY

PART TWO

It is all about charge!

neutron= no charge

proton = + charge

electrons = - charge

The flow of electrons and protons is what we call electricity. Electrons surround the atom´s centre, the nucleus. Protons and neutron stick together inside the nucleus

ELECTRICITY

• When there is an equal number of electrons and protons= NEUTRAL CHARGE
• Sometimes,however, it is possible for electrons to move from atom to atom.This result in an unequal number of electrons and the atom becomes positively charge or negatively charge (Look at the page 82)

It is all about charge!

There are two types of electrical charge: NEGATIVE and POSITIVE

ELECTRICITY

Example: Plastic

Insulators

Conductors

Example: Water

ELECTRICAL CURRENT Happens when there is an exchange of electrons between elements .Such elements are called conductors. Conductors allow electrons to move without much resistance. Insulators don´t allow electrons to move easily

Example: Electrical storm

Forms of electricity

STATIC ELECTRICITY Is energy that doesn´t flow .It occurs when electrons form a negatively charged object are transferred to a positevely charged object

ELECTRICITY

• POWER SOURCE: provide energy (example: battery )
• CONDUCTOR: allow electricity to pass through (example: wire )
• SWITCH:to open and close the circuit
• LOAD: which convert electricity to another form of energy (example: light bulb )

And a electrical current can be produced and transported in a closed electrical circuit. And an electrical circuits has four parts:

Electrical circuits

ELECTRICITY