5. (a) State two assumptions of Dalton's atomic theory of 1808 - Leaving Cert Chemistry - Question 5 - 2010
Question 5
5. (a) State two assumptions of Dalton's atomic theory of 1808.
(b) The electron was the first of the sub-atomic particles to be discovered. It was identified in ex... show full transcript
Worked Solution & Example Answer:5. (a) State two assumptions of Dalton's atomic theory of 1808 - Leaving Cert Chemistry - Question 5 - 2010
Step 1
State two assumptions of Dalton's atomic theory of 1808.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
All matter is composed of very small, indivisible particles known as atoms.
All atoms of a given element are identical in mass and properties.
Step 2
Name the scientist
(i) who, about 1897, measured the ratio of charge to mass of the electron, e/m,
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
J.J. Thomson.
Step 3
Name the scientist
(ii) who, about 1910, proved that the electrons in an atom reside in an electron cloud surrounding a small dense positive central nucleus.
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Ernest Rutherford.
Step 4
Name the scientist
(iii) who, about 1911, measured the charge on the electron, e.
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Robert Millikan.
Step 5
Outline Bohr's atomic theory based on the hydrogen emission spectrum.
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The electron in a hydrogen atom occupies fixed energy levels (discrete energies).
An electron in an energy level does not radiate energy.
The electron occupies the lowest energy level available or ground state.
The electron can move to a higher energy level if it receives an amount of energy (photon of energy).
The photon emitted when transitioning back to lower energy levels must match the energy difference between the levels.
Step 6
State two limitations of Bohr's theory that led to its modification.
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Bohr's theory did not account for atoms with more than one electron.
It did not take wave-particle duality into account.
Step 7
Define atomic orbital.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
An atomic orbital is a region of space around the nucleus of an atom where there is a 99% probability of finding an electron.
Step 8
State the shape of the p-orbital.
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The p-orbital has a dumbbell shape.
Step 9
State the maximum number of electrons that can be accommodated in a p-orbital.
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The maximum number of electrons that can be accommodated in a p-orbital is 6.
Join the Leaving Cert students using SimpleStudy...
