Download Describe an atom. What is it made up of?

Describe an atom.
What is it made up of?
What is the difference between electrical insulators
and electrical conductors?
(Use the term “electron” in your answer)
What is the difference between positively and negatively charged objects?
(Use the term “electron” in your answer)
What are “induced charges”?
What is an electrical field?
When two different materials are rubbed together do
they acquire the
same type of charge or different types of
charge?
What is voltage?
What is current?
How is the unit 1 A defined?
In an insulator electrons are bound to their atoms. In a
conductor they can move freely.
If you approach a conductor with a charged
rod, the electrons in the condoctor will be attracted and move towards the charged rod.
After removing the rod the electrons will move
back.
The nucleus of an atom consists of protons (positively charged) and neutrons.
-
+
-
+
-
+
+
-
-
-
+
+
-
+
-
+
-
-
Negatively charged
(more electrons
than protons)
When two different materials are rubbed together they
will acquire
different charges. One material will lose electrons
(becoming pos.) and
the other will gain electrons (becoming neg.).
+
-
+
+
-
+
-
Positively charged
(lack of electrons)
If you bring a charge in an electric field it
will be either attracted or repelled.
The field lines have the same direction as
the force acting upon a positive charge.
A positive charge would move downwards. Thus the
field lines point from top to bottom.
Current tells you how much charge passes through a
point in the conductor per second.
Current = Charge / Time
If 1 Coulomb passes per second the current equals 1
Ampere.
Voltage propels the electrons. It does work on the
electrons hence they gain energy.
How can you compare voltage and pressure?
How do you measure voltage?
(How would you measure pressure in a tube?)
How do you measure current?
What is resistance?
(How would you measure the flow rate of water in a
tube?)
What factors does the resistance of a wire depend on?
Ohm’s Law
Which charges repel / attract each other?
What is an ohmic resistor?
(Draw it’s circuit symbol, too)
A battery is analogous to a pump in a water
circuit. A pump takes in water at low pressure
and does work on it, ejecting it at high pressure.
A battery takes in charge at low voltage, does
work on it and ejects it at high voltage.
Current equals the amount of water passing
through the tube.
The resistance equals voltage divided by current.
Hence: The smaller the current the greater the resistance.
A material which decelerates the electrons more than
another has a greater resistance.
Voltage = Resistance x Current
The greater the length, the greater the resistance.
The greater the cross-sectional ares, the smaller the
resistance.
Material: The greater the resistivity, the greater the
resistance. (E.g.: Copper has a small resitivity)
The higher the temperature, the greater the resistance.
If current and voltage are proportional, the resistor is
ohmic.
Circuit symbols
Unlike chages attract:
german:
Like charges repel:
english: