Unit 5 Lesson 1 Flashcards
proton
gives identity
equal to the atomic number
element
simplest unit
atom
basic unit
given the credit who discovered protons
Eugen Goldstein
where is electron?
outside the nucleus
who discovered electron?
Joseph John Thomson or J. J. Thomson
Nucleons
Protons and Neutrons
who discovered neutron?
James Chadwick
Atomic weight
Protons+Neutrons(because most of the weight are proton and neutron because they are heavy)
Atomic number symbol
Z=p⁺
Atomic Mass
A=p⁺+n⁰
p⁺=e⁻ is true?
yes
According to Democritus, the world is made up of tiny indivisible particles called
Atomos
Non atomicism and atomicism
Aristotle and Democritus
Arm chair scientists
Theorists?
Indivisible,indestructable,Uncattle
Atomos
proposed the solid sphere model of the atom in 1803
John Dalton
made the plum pudding model of the atom
Sir J. J. Thomson
discovery of the nucleus.
He proposed a new model which he called the nuclear model of the atom.
Lord Ernest Rutherford
Most α particles passed straight through the gold foil, which showed that atoms are mostly empty space. The empty space is where?..Some of the α particles were deflected at various angles, and sometimes even back at the radioactive source
l
In 1913, he improved Rutherford’s model by adding the concept of orbits.
Neils Bohr
are stable discrete regions where electrons do not experience spontaneous energy absorption and emission.
Orbits
Also energy levels
Orbits
It denotes a certain distance from nucleus.
energy levels
Bohr’s model introduces the concept ___
___ ____of wherein each orbit (or energy level) has a definite amount of energy.
quantized energy levels
The amount of released energy in the form of light is equivalent to a specific wavelength of light.
true
The specific wavelength is observed as the atom’s resulting spectrum.
l
Bohr’s model is useful in explaining observations on hydrogen and hydrogen-like atoms but fails to explain phenomena for larger atoms.
It cannot account for atoms with more than one electron that have spectral lines in pairs.
Fallbacks of Bohr Model
developed the wave-particle duality in 1924.
According to his theory, subatomic particles, like electrons, can also act as waves, rather than definite particles with determinate positions.
Louis de Broglie
The model also indicates that the exact position of an electron cannot be precisely determined.
l
The uncertainty principle states that two paired variables cannot be simultaneously determined with precision in a quantum system.
l
It denies the probability of having electrons in definite orbits as stated in Bohr’s model.
l
It denies the probability of having electrons in definite orbits as stated in Bohr’s model.
l
It denies the probability of having electrons in definite orbits as stated in Bohr’s model.
l
Electrons in the quantum mechanical model are in regions called ___, where electrons can only most probably be foun
orbitals
