5. Models of the atom Flashcards
What is the problem with Dalton’s model of the atom?
Too primitive, doesn’t take into account the subatomic particles
What is Thomson’s atomic model?
plum pudding model. Atom as a homogenous sphere with a positive charge and electrons distributed evenly inside.
What were the 2 main problems with Thomson’s atomic model?
- Does not explain the line spectrum of H2
2. Did not explain the existence of the nucleus
What did Bohr’s atomic model assume?
- Electrons occupy certain distinct orbits
- They do not radiate in these orbits but have constant energy
What did the Davisson-Germer experiment show?
It showed the wave nature of the electron
What crystal was used in the Davisson Germer experiment?
Nickel-chloride crystal
What is Heisenberg’s uncertainty equation?
The position and the velocity of an object cannot both be measured exactly, at the same time, even in theory : the more you know about an electron’s position, the less you know about the momentum
What is a bound electron?
electron that only accepts energy in discrete amounts
What is the 1st quantum number?
principle number, n
What is the 2nd quantum number?
subsidiary number, l
What are the possible values of the 2nd quantum number?
0 < L < n - 1
What is the periodic table?
A tabular arrangement of the elements according to increasing atomic number Z
What is metallic character?
Ability of an element to lose an electron
