Electron Theory Flashcards
A neutron has
no electrical charge but will add weight to the nucleus.
The unit which consists of two or more different types of atoms is known as a
molecule of a compound.
In what equipment is a photon radiated when an electron leaves a hole?
LED.
A good electrical insulating material will contain
strongly bound electrons in the atoms of the material.
The smallest particle that a substance can be split and show the same properties as the whole is known as
an Atom.
What charge does the nucleus of an atom possess?
Positive.
What is the maximum number of electrons in shell N of an atom?
32.
Shell k = 2 electrons, shell L= 8 electrons, shell M = 18 electrons and shell N = 32 electrons (or use the 2n2 exclusion rule).
An oxygen molecule is made up of
two oxygen atoms sharing electrons.
If electrons are added to an atom it becomes
a negative ion.
An element whose atoms have fewer than 4 electrons in their valency shell are
good conductors.
The further away from a ‘complete’ shell the better a conductor it is.
The charge on a proton is
positive.
What effect do the electrons of one atom have upon the electrons of another atom?
They repel each other.
What is a molecule?
The smallest part of a compound.
An atom is
the smallest part of an element that retains its characteristics.
A neutron is a particle which is
contained within the nucleus of most atoms.
Most atoms’ because hydrogen has no neutron.
The mass of an atom is contained mainly in the
nucleus.
The proton and the neutron are approximately the same mass (neutron very slightly heavier). The electron is just under 1/2000th of a proton or neutron.
When an atom loses or gains an electron it is called
an ion.
A good electrical insulator is a material which
has its electrons tightly bound to their parent atoms.
An electric current is
an ordered flow of electrons.
An atom contains
Protons neutrons & electrons.
Germanium and silicon have how many electrons in their outer shell?
4.
All semiconductors (including carbon) has 4 electrons in their outer shell.
If a free electron is given to another atom, that atom is a
negative ion.
That atom will be negatively charged due to the additional electron.
The atomic number of an atom is determined by the number of
protons.
Atomic number = number of protons. Mass number = number of protons + neutrons.
The valence electron is
the electron in outer shell of atom.
An atom with a deficiency in electrons has
low resistance.
An atom with a deficiency of electrons will be positively charged and able to accept electrons freely. Module 4 theory of holes as majority carriers.
An atom with less than 4 electrons in its outer shell has
low electrical resistance.
Low electrical resistance, i.e. a good conductor.
Elements such as phosphorus with 5 electrons in their outer shell, when combined with pure silicon, is a
donor.
Phosphorus ‘donates’ an electron to the silicon crystal structure.
A hydrogen atom consist of a
Proton and an Electron only.
Hydrogen has no Neutron.
For an atom to become a negative ion it must
gain at least one electron.
Gaining at least one electron produces a negative ion.
What is the maximum number of electrons in shell M of an atom?
18.
Use Pauli’s exclusion formula. M is the 3rd shell (n=3). 233 = 18.
A neutral atom with an atomic no. of 3 has how many electrons?
3.
Atomic number = number of protons = number of electrons.
The nucleus of an atom is
positive charged.
Electron orbits are called
shells.
shells, or energy levels.
What happens when a neutral atom gains electrons.
It gains a negative charge.
An oxygen atom has
protons, neutrons and electrons.
What are the names of the shells on an Atom
K, L, M, N, O, P, and Q, or 1, 2, 3, 4, 5, 6, and 7. The K shell is the innermost shell, and the Q shell is the outermost shell