Electronics: Foundations Flashcards
What does an atom consist out of?
An atom consists of a cloud of negatively charged electrons surrounding a dense nucleus that contains positively charged protons and electrically neutral neutrons.
Kindle Edition.
definition of matter
Anything that has mass and occupies space
What is an element?
Pure matter that consists out of one type of atom
What does the atomic number indicate?
The number of protons in each atom
What is an isotope?
A variation of in the amount of neutrons of an atom. Variants are called isotopes
How many elements in the periodic table
118
How to tell how much electrons an atom has?
Atomic number. The atomic number indicates the amount of protons an atom has. A stabe atom has an equal amount of protons and electrons
What doe the nucleus of an atom contain
protons and neutrons
What are shells?
Shells are the pathways in which electrons travel around a nucleus
How many electrons can each shell hold?
2, 8, 18, and 32
What is a valence shell?
The outermost shell of an electron
What are valence electrons?
Electrons that inhabit the outer shell of an atom
What is the relationship between the valence shell and current?
The more full the valence shell, the less likely it is that an atom will lsoe electrons when a force is applied. The full the valence shell, the more likely it is to lose electrons when a force is applied.
What is an ion
An atom with a charge. A possitive charge results when protons are more than electrons. A negative charge results when electrons are more than protons.
What is emf?
Electromagnetic force (emf) is that attraction between positive and negative charges and the repulsion of like charges. It is the basis of interaction between the protons and electrons within atoms holding them together, and the attraction between atoms that have negative and positive charges.
What is electricity?
The movement of electrons between atoms
What is the movement of electricity dependend on?
emf
What is conventional theory?
The early belief that electricity traveled from a positive to a negative charge
What is Electron theory?
Electron theory states that electricity flows from negative to possitive.
conductivity
The tendency of a material to allow the free flow of electrons
Resistance
The tendency of a material to resist the flow of electrons
condutivity is determined by…
How full or empty the valence shell of an element’s atoms are
What side of the periodic table consists of good conductors
Elements on the left have fewer electrons in their valence shell, which makes them good conductors
What side of the periodic table consist of insulators?
Elements on the right are noble gasses and are less conductive and have fuller valence shells.
Which elements have only 1 valence electron making them good conductors
Silver, Gold, Copper
Which elements are good insulators
Noble gasses like Neon, Helium, Argon, Krypton, Xenon and RAdon
Which elements on the periodic table are semic conductors
The once in the middle
Which elements are commonly used semiconductors
Silicon and germanium
What is doping?
Adding an impurity to a semiconductor to improve it’s conductivity
N-type semiconductor
A doped Semiconductor that allows a negative charge to flow through it.
P-type semiconductor
A doped semiconductor with a possitive charge.
An example of an N-type semiconductor
Doping silicone with phosphor
An example of a P-type semiconductor
doping silicone with Boron
factors that determine conductivity
- Atomic qualities
- Physical qualities: Diameter, Length
- Temperature: Changes conductivity
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How does temperature influence conductivity?
Metals tend ot become less conductive when heated ans some become super conductive at extremely low temperatures
explain electron and hole flow
The movement of the electrons is called electron flow. The opening up of the gaps is called hole flow.
What are electrons?
Negatively charged particles
