Unit 1 Flashcards
(42 cards)
What is Democritus famous for?
Credited for first formalizing a particle theory of matter
Believed all matter was made of small, indivisible particles called atoms.
What are the 6 points of Democritus’ theory?
Atoms are particles in the void Atoms are always in motion Atoms are indivisible Atoms come in different sizes Atoms make life predictable The human souls is made of soul atoms
What is John dalton most notable for? What does his model look like?
He re established the atomic theory in 1808
Explained the law of conservation of mass
It was simply just a sphere
What is daltons atomic theory?
All matter is composed of small particles called atoms
Atoms of the same element are identical
Atoms cannot be created divided or destroyed
What is JJ Thomson most notable for? What did his model look like?
He used a cathode ray tube to notice that there were negative and positive charges in an atom
His model looked like a positive sphere with floating negative particles in it
(Plum pudding)
What is Robert Millikan most notable for?
He found the mass of an electron to be 1837 times smaller then the smallest atom
What is Ernest Rutherford most notable for? What does his atom look like?
Rutherford used his thin gold sheet experiment to find that the centre of an atom is positive and called it the nucleus
He also said that electrons orbited the nucleus like planets orbit the sun
His atom had a circle centre filled with proton a while electrons orbited on lines around it (jimmy neutron logo)
What is the formula to find the speed of light?
C=(upside down y)f
C= speed of light
Upside down Y= wavelength in m
F= frequency in Hz
What is the speed of light?
3.00x10^8
What is the photoelectric effect?
When light is shined on a certain metal surface, electrons can be liberated and detected. If the frequency is too low no electrons will be emitted but if it is high enough a single photon of light is enough to liberate an electron
What is the formula used in the photoelectric effect used to calculate the energy of a photon?
E=hf
E= energy of photon in J
H= planks constant in J•s
F= frequency in Hz
What is Plancks constant?
6.626 x 10^-34 J•s
What is the formula used to calculate the kinetic energy of an emitted electron?
KE=hf-ø (o with a vertical line through it) KE= kinetic energy h= planks constant f= frequency Ø= binding energy of electrons in J
What is Niels Bohr most notable for? And what did his model look like?
He proposed that electrons can occupy only certain energy levels and that the electron orbital lowest in energy is closest to the nucleus.
His model looks like current day one it has a centre nucleus with electron circle orbits around it
How do scientists determine where electrons are in an atom?
They use light or photons to knock electrons off course and create a probability cloud since you can’t exactly pin down where electrons are
What are the four quantum numbers?
- Principle quantum number
- Angular momentum quantum number
- Magnetic quantum number
- Magnetic spin quantum number
What is the principle quantum number? What is its symbol?
It describes the energy level of the electron and how many orbitals you have
Represented by the letter n
N= number on the side of periodic table (row 1,2,3,4,5)
N= 1,2,3,4,5
What is the angular momentum quantum number? What is it’s symbol? What are the different kinds of orbitals?
It describes the type of orbital
Represented by the letter L
S orbital - 1 balloon (circle)
P orbital- two balloon stacked (one top one bottom)
D orbital - 4 balloons ( + one coming from each corner)
What is the magnetic quantum number? What is it represented by?
Describes the orientation or shape of the orbital, ranges from -1 to +1
Represented by ml
What is the magnetic spin quantum number? What is it represented by?
Describes the spin of the electron, ranges from -1/2 to +1/2
Represented by ms
What are hadrons?
Composite particles made from quarks held together by the strong force.
What are the two types of hadrons? Examples of each?
Baryons- made from 3 quarks
Ex: protons and neutrons
Mesons- made from 1 quark and 1 anti quark
Ex: pions and Kaons
Who is the father of the periodic table?
Dmitri Mendeleev
What is atomic radii? How does it change moving across the periodic table?
It is the size of the atom
The atomic radii gets bigger moving left and down a group 👈🏼👇🏼
This is like this because elections are filling higher energy levels which are further from the nucleus (orbitals) making it bigger
There is also more protons going right across the periodic table which makes a tighter bond and decreases the size
