Static Electricity

What is an atom made up of?

A positively charged nucleus containing positive protons and neutrons, surrounded by tiny negatively charged electrons. The electrons are in constant motion and travel relatively far away from the nucleus.

What is an element?

A substance whose atoms all have the same atomic number.

Difference between how insulators and conductors hold their electrons.

Insulators: Hold them tightly Conductors: Hold them loosely.

What is grounding?

It is neutralizing something.

What is the atomic number (Z) of an atom?

It the number of protons that the atom has in the nucleus.

State the law of attraction and repulsion:

Like charges repel and unlike charges attract.

What is the universal sign for grounding?

Look at picture or notes.

What makes the sound of lightning/thunder?

Electrons splitting the air.

What are examples of fair conductors?

-silicon -carbon -earth -human body -humid air

What are three ways to charge an object?

1) Contact 2) Friction 3) Induction (bringing it near)

What are the 3 parts of an atom?

1) Protons (+) 2) Electrons (-) 3) Neutrons (o)

What are four examples of a good conductor?

1)aluminum 2)copper 3)gold 4)iron (Basically any kind of metal)

What are four examples of a good insulator?

1)fur 2)cotton 3)plastic 4)rubber

Difference between charged by contact and charged by induction?

Charging it by contact is when it touches the object. Charging by induction is when it goes near it.

How can you ground an electroscope?

By providing a conductor to allow passage of the charge to the earth, which is huge and can accept a very large charge without any significant change to its charge. For example, by touching a finger to a charged electroscope a persons body provides passage to the earth.

How does lightning occur?

During a storm, negative charges collect up at the bottom of the clouds while the higher parts of the cloud are positively charged. The negative charges in the cloud repel the electrons from the earth which leaves the ground positively charged. The strong attraction between the bottom of the negatively charged cloud and the positively charge ground pulls electrons off atoms and molecules in the air. Once a chain of charged atoms and molecules forms the negative charge in the cloud can flow down the channel to the positively charged earth. So many electrons crash through the air so quickly that they collide with other molecules and not only light up the air but also heats it. When air molecules collide with other molecules as they move, they produce a shock wave that we call thunder. This all usually happens over the highest point on the ground. The heat can trigger forest fires, a house fires and if lightning hits a person it will almost always kill them.

What does a charged object have?

Either extra electron to make it negatively charged or fewer electrons to make it positively charged.

When an atom becomes charged what part of the atom has moved?

Electrons

An atom with a negative charge has gained what, how do you know?

Electrons because electrons are negative.

How does a lightning rod work?

Electrons travel most easily through conductors and that is exactly what a lighting rod is based on. They are used to draw lightning's electrical charge away from a structure. The rod is charged by induction (bringing near/not contact) The rod which is positively charged attracts the negative ions in the air while the cloud attracts the positively charged ones. A chain of ions forms between the cloud and the lightning rod which acts as a conductor. This provides a path for the lightning bolt. When the bolt strikes it hits the lightning rod as it is the highest point in the area. The electrons from the lightning are carried around the building and into the ground by a conductor usually made of wire or some kind of metal. Because the electrons don't go through the building they cannot start a fire.

What is the science of static electricity?

Electrostatics

What happens when two insulators are rubbed together?

For example if a comb and a piece of wool rubbed together, friction can cause electrons to get knocked off one object and transferred to the other.

What is the fluid theory?

In 1600, William Gilbert proposed electricity was a fluid separate from the matter that made up objects. This theory was accepted by scientists for hundreds of years, however, was discarded when J.J Thompson discovered the electron.

(Fill in the blank) When an object becomes discharged it now has a _______ charge.

Neutral

Can individual charges move through a neutral object?

No but the charge can be attracted to charged objects through rearrangement of the distribution of charges within the neutral object.

How do charged and neutral objects interact?

No matter if an object is positively or negatively charged it will attract a neutral object.

What are fair conductors?

Object in between insulators and conductors. They will allow electrons to move but not freely move. These fair inductors provide a lot of resistance to the movement of electrons.

What is a conductor?

Object that allows charge to move freely and pass through it.

What is an insulator?

Object that does not allow charge to move freely or pass through it.

Draw a diagram of how you charge an object negatively by contact.

On sheet

What is there in every atom of every element?

One electron for every proton.

What are the laws of attraction and repulsion?

Opposite charges attract. Like charges repel.

What is the electron theory of charge?

States that objects that lose electrons become positively charged and ones that gain electrons become negatively charged.

What does a meteorologist do?

Person who studies atmospheric conditions and weather.

What did Benjamin Franklin name the two types of charges?

Positive and negative.

An atom that has lost electrons has what charge, how do you know?

Positive because there are more protons left over.

What is the difference between protons, neutrons and electrons?

Protons: -positive charge -inside nucleus of atom -gives the atom its identity. Atoms of the same element have the same number of protons and atoms of a different element have a different number of protons. Neutrons: -neutral charge -inside nucleus of atom Electrons: -negatively charged -fast moving particles -form a cloud surrounding nucleus of atom -governs the behaviour of an atom. The number of electrons can be increased decreased or remain unchanged.

How is something grounded?

Providing a conductor to allow passage of the charge to the earth. To ground a conductor means to connect it, through conducting material, directly to the ground. For example if you want to remove or gain electrons from your apparatus, attach a wire to a metal object like a water pipe that goes into the ground.

How did they find this out? (electron theory)

Scientists discovered every charged object fits into one of two categories. They found out that every charged object in category A repels all other objects in category A and attracts the ones in category B. (vice versa) All objects in A hold one type of charge and B holds another.

What do the electrons do in insulators?

They tend to remain around individual atoms and don't flow from one atom to another.

Why do electronics need to be grounded?

To prevent electric shocks.

How do two charged objects interact?

Two objects with the same charge will repel each other. For example two positively charged objects will repel or two negatively charged objects will repel. However, one positively charged object and a negatively charge object will attract. Opposites attract! ;)

What does charge mean?

Used to describe objects that attract other objects after being rubbed.

When is an object neutral?

When it has the same number of protons and electrons.

What creates a spark?

When two oppositely charged objects approach each other a spark or electrical discharge will occur. The excess electrons on the negatively charged object jump through the air to the positive object. After the spark the objects are no longer charged.

When we charge a balloon on our hair why does it stick to the wall when wall's overall charge is neutral?

When we charge the balloon it becomes negatively charged. Either if an object is negative or positive it will attract to a neutral object so the balloon attracts to the neutral wall. It forces the electrons in the wall to move back and attracts to the protons on the surface of the wall.

What happens to the electrons when ebonite is rubbed with fur? (electron transfers and resulting charge)

~It becomes negative because it gains electrons. ~The electrons transfer from the fur but since fur is an insulator it can only transfer the electrons by friction. (rubbing together) ~The fur is positive because it transferred its electrons to the rod which is now negative.

What is the purpose of an electroscope and how does it work? (also explain the electroscope lab)

~Used to detect presence of static electric charge. ~They have two strips of metal that bend easily which are attached to a central metal rod with a sphere at the top. (In the beginning the leaves are neutral) ~When a negatively charged rod touches the sphere negative charge spreads throughout the whole electroscope. This makes the leave both negatively charged which makes them repel. ~When a positively charged rod touches the sphere negative charges move towards the sphere and the leaves become positively charged which makes them repel. ~The rod does not need to touch the sphere to make them repel. If you bring the negatively charged rod near it will will repel the negative charges in the sphere and the sphere will be left with a temporary positive charge. When you take away the rod the leaves will go back to their original position. (This is charging by induction)

Explain how to charge an object by friction and what charge would result on each material?

~You would charge it by rubbing one object with another. ~The object rubbed would be negative while the object it was rubbed with would be positive.