Science ETT

Describe the basic structure of an atom 17

• Protons are positively charged and are positioned in the nucleus of the atom
• Neutrons are neutral charged and are positioned in the nucleus of the atom
• Electrons are negatively charged and are orbit the nucleus
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Electricity is Flow of electric charge 18

• Explain that electricity is the flow of electric charge. In an electrical circuit this charge is often carried by moving electrons.
• In an electrical circuit, the electrons flow around the circuit giving energy from the energy source which is also known as a flow of electrical charge. Electricity is the flow of electrical charge. the energy flows as a current and can be resisted by resistors like globes, the energy comes from the cell or battery and pushes the energy around the circuit

Objects become charged 19

• Explain how objects can become ‘charged’ and that charged objects exert forces on other objects.
• An object gets charged when it's atoms lose or gain an electron to become more positive or negative. For example: ... This means that the fur loses it's electrons to the plastic rod and both objects are now charged. The fur is positively charged because it lost electrons and the rod is negatively charged because it gained electrons. Once they are charged, it can attract and exert forces on other objects that have an opposite charge, which means it attracts and forces the material closer to the object, the objects will repel if they have the same charge like positive and positive, so they won’t exert forces and will repel forces away from each other

Electrostatic Forces 20

• Understand that an electrostatic force can be an attractive or a repulsive force.
• Electrostatic Force: Electrostatic forces are non-contact forces; they pull or push on objects without touching them. Rubbing some materials together can result in something called 'charge' being moved from one surface to the other. Charged objects pull on other uncharged objects and may either push or pull on other charged objects.
• Forces can only attract if they are opposites, for example protons and electrons (positive and negative)
• Forces can repel if they are the same or alike forces for example positive and positive and negative and negative.

Van Der Graff 21

• Describe how a Van Der Graaf generator demonstrates electrostatic forces in action.
• The description of a Van Der GRAAF: once the power is turned on, below the silver dome, a rubber/plastic belt quickly moves up and down the rollers in a circular motion to produce friction and electricity, once it is produced in the silver dome, it’s electrons are stripped away from the electricity leaving only protons meaning the electricity is positive. If a neutral charge comes near it takes the electrons to become neutral, that’s when you see the lighting between the objects. Meaning the electrons are being passed on to the van der graaf. However it does not become neutral, the dome still strips away the neutrons until it is turned off. You can see that this is an example of electrostatic force, the particles attracting and the shocks of the movement of electrons and friction to cause energy,

Static VS Current Electricity 22

• When electricity is at rest, it is called static electricity. It refers to the electric charges that build up on the surface of materials or substances. These so-called static charges remain until they are grounded, or discharged. Static electricity is generated by friction, or sudden contact – for instance, rubbing two materials against each other. Ordinarily, atoms are ‘uncharged’. These are considered neutral substances, but they can lose or gain electrons through friction. The rubbing procedure can cause the atoms of particular substances to lose their electrons. This loss of electrons will make the substance or material become positively charged. The excess protons caused the substance have a positive charge. Conversely, the substance that gains the electrons is said to be negatively charged. Certain atoms readily lose electrons, and it goes the same way with particular atoms which have the tendency to accept them. When these two substances are rubbed together, the potential of generating static electricity is great.
• Current electricity, on the other hand, is a phenomenon of moving electrons in a particular path, or direction, such as a stream of them flowing through conducting materials. Current electricity can come from various sources. The most commonly used source of current electricity is from batteries. These batteries rely on the chemical reactions within them to produce electricity. Current electricity, in huge amounts, is typically brought about by generators. Power plants have many of these to produce enormous quantities of current electricity. The phenomenon is usually controlled, and requires a flow of electrons along a path, which is fittingly called the ‘electric current’.

Recall and Draw Symbols of Circuits 23

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• Bildunterschrift: Recall and draw symbols for electrical components in simple circuits
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• Bildunterschrift: Example of Simple SERIES Circuit

Series VS Parallel Circuit 24

• A parallel circuit is a circuit with more than one conducting pathway through which the current can flow.
• A series circuit is one, which contains only one possible conducting pathway through which the current can flow.
• This means a series circuit has only ONE way for the electrons to move and flow, but a parallel circuit has 2 or MORE ways for the electrons to flow and move.

Voltage 25

• Pushing force of electrons within a circuit, it’s like pressure in water, more voltage more pressure and more water flow, more voltage, means more electron flow. The voltage comes from the battery or cell, it pushes the electrons through the circuit if there are more than one cells, there will be more voltage and electrons. voltage is measured in volts.

Current 25

• Flow of electrons measured in amperes (amps) past a single point within a set amount of time, the faster the flow, the more current. In other words, it is the amount of charge or electrons that passes through a point in the wire per second. The current is basically the flowing of electrons, the flow can be slowed down by resistors. there could be less current if there is less voltage.

Resistance 25

• A restriction into the flow of electrons. Resistance measured in ohms. Longer the wire, greater resistance, thicker wire, lower resistance, resistance is different for each material and temperature of material can change resistance to flow of electrons, shorter the wire, less resistance. Resisters can restrict flow of current. The resistance slows down the current flow of the electrons, the current becomes weaker. an example of a resistor in a circuit can be a globe, switch or resistor.

Relationship-Voltage,Current,Resistance 26

• The voltage (cell or battery) pushes the electrons around the circuit, making the current where the electrons flow. resistance like a globe or switch restricts or makes it harder for the electrons to push through. This repeats again.

SI Unit For Voltage, Current, Resistance 27

• Resistance- ohms
• Current- amps
• Voltage- volt
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• Bildunterschrift: Table Of Measurements

Electrical Safety 28

• To much current flowing in a electrical circuit can cause overheating and possibly electrical shock, because none of it is being discharged by touching something neutral, a three pin cord can reduce it, the top pin is an earth cord and takes all dangerous electricity to the ground to stabilise and make it neutral
• You should not use a damaged or frayed cord, because the wires are left open and exposed, meaning the wires containing current may heat up or electrocute you, via open wires.
• Switch boards are the circuit breaker, they control the electricity flowing throughout the house, when turning it off, it will turn of the electricity and stop the flow of electrons to prevent hazards
• Fuses are made of metal, when they get really hot and melts it will break the circuit turning off electricity, meaning you can’t use it anymore, the electricity is turned off meaning it isn't a hazard and that you can't harm yourself, they are a safety feature.