Vocabulary & Memory Work
Conductor
A material through which electrical charge can easily flow.
How do atoms become charged?
An atom can become positively charged by losing electrons and negatively charged by gaining electrons.
What is electric current, and how is it measured?
Electric current is the flow of electricity from one place to another. We use amperes or amps to measure electric current.
Why do organic compounds that are slighly acidic able to conduct electricity?
This is due to the ions present in an acidic solution.
The electrical charge can move freely through the substance and the presence of ions allows the charge to do just that.
What is the difference between a cell and a battery?
A cell is the basic unit that can produce electricity. A battery has two or more cells.
Electrical Charge
A charge produced by an excess or shortage of electrons.
What is the difference between a conductor and an insulator?
A conductor allows current to pass through, but an insulator does not.
Potential difference is necessary for electric current to flow, as there has to be the potential for the electrons to flow between two places.
What is Ohm's law?
Ohm's law states that the voltage across a conductor is directly proportional to the current flowing through it, provided all physical conditions and temperature, remain constant.
I=V/R
What are the basic components of a simple cell?
The basic components of a simple cell are two plates of metal and an electrolyte solution (either a salt or an acid).
Induction vs. Insulator
Induction is the transfer of electrical charge without contact between the materials while an insulator is a material through which electrical charge cannot easily flow.
What is static electricity? How does it work?
Static electricity is a stationary electrical charge that can be held by a material.
The electrons from one object are rubbed off onto another object, creating a static charge.
What is electromotice force?
Electromotive force is the potential difference that is produced by a source, such as a battery or generator.
Explain what a circuit is and the difference between conventional and electron flow.
A circuit is a closed loop, consisting of a source of potential difference and one or more components, around which the electricity flows.
Originally, current was assumed to flow from a battery's positive terminal to its negative one, but electrons actually flow the other way.
What is the difference between a primary and secondary cell?
A primary cell has a limited life, whereas a secondary cell can be recharged.
Cathode and Anode vs. Cation and Anion
Cathode is a negatively charged diode and an anode is a positively charged diode. A cation is a positively charged ion and a anion is a negatively charged ion.
Recall: an electrical component that allow electrical current to flow in and out in a single direction.
If there is a current of 45 amperes in a circuit for 2 minutes, what quantity of electric charge flows through the circuit?
Q= I x T
5400 C
45 x 120
What does it mean to "dope" a semiconductor and why would you do that?
To dope a semiconductor means to make it impure. This is done in electronics to make either a negative or positive semiconductor, which allows for the electrical current to be carried through a device.
What is a dielectric?
A dielectric is a material used to fill the space between the conductors.
Ex: A capacitor is a two-terminal electrical device that can store energy in the form of an electric charge. It is made up of two electrical conductors separated by a distance. The space between the conductors may be filled by a vacuum or with an insulating material known as a dielectric.
What is capacity?
Capacity is the ability of a cell to produce current over time.
Law of Electrostatics
Like charges repel each other and opposite charges attract each other.
How much current must there be in a circuit if 476 coulombs flows past a point in the circuit in 7 seconds?
68 amps
Q= I x T
476= I x 7
How does electricity come into our homes?
Electricity is produced by large generators at a power plant, and then alternating current passes through lines from the plant to the place where it is used. Transformers along the way adjust the current to the appropriate amount for the place it is going. The electricty is delivered via two wires from a substation.
A 6 volt battery transfers 13 C of electrical charge between the two terminals. How much energy is transferred.
V=E/C
V= E/C
6=E/13
E=78 J
What are two ways of reducing the amount of hydrogen in a cell?
By adding a depolarizing agent where it bonds with hydrogen to form water.
Coating the zinc plate with an amalgam which prevents the production of hydrogen.