Chapter 8: Electron Configurations and Periodicity Flashcards
Who discovered radium in 1989?
Marie Curie
Why do atoms react to magnets?
Atoms themselves are magnetic due to the electrons in the atoms behaving as tiny magnets. As noted when naming atomic numbers. The M1 field states that magnets can spin either +1/2 or -1/2
What is an electron configuration of an atom?
Particular distribution of electrons among the available sub-shells.
What is a subshell?
A group of orbitals having the same n and l quantum numbers but different m1 values.
What is the Pauli exclusion principle?
No two electrons in an atom can have the same four quantum numbers. SO –> If one electron in an atom has quantum numbers n=1, l=0, m1 = 0, and Ms = +1/2 - no other electron can have these quantum numbers.
REVIEW: What do N, L, Ms, M1 mean
N = Energy level (the further away from the nucleus, the higher the energy)
L = The shape of the orbital (S: LO [circular], P:L1 [Infinity sign], D: L2 [Clover], F: L3 [WACKY])
Ml = Orientation (Will always vary between +L and -L
Ms = Electron spin - only +1/2 or - 1/2
What is Aufbau’s Principle?
You need to build configurations from the ground up. (1s and then 1s + 2s and then 1s + 2s + 2p and then 1s +2s + 2p + 3s)– etc
How do you write electronic configurations for ions?
You take the atomic number (Example Fe+2 as an atomic number originally of 26 and since the charge is +2 the atom lost 2 electrons and you now you need to get it to 24)
What are the two exceptions to the building up principle?
Chromium [Ar] 3d5 4s1
Copper [Ar] 3d10 4s1
What is the order of successively filling sub-shells?
1s(2), 2s(2), 2p(6), 3s(2), 3p(6), 4s(2), 3d(10), 4p (6), 5p (6), 6s, 4f, 5d,
What is Hunds rule?
In 1927 Friedrich Hund stated that the lowest-energy arrrangmentf of electrons in a subhsell is obtained by putting electrons into seperate orbitals of the subshell with the same spin before pairing electorns.
What does periodic law state?
When the elements are arranged by atomic number, their physical and chemical properties vary periodically.
What are three main physical properties of an atom?
- Atomic Radius: Maximum in the radial distribution function of the outer shell of the atom.
- Ionization Energy: the minimum energy needed to remove the highest-energy electron from the neutral atom in a gaseous state.
- Electron affinity: The energy required to remove an aelectron from the atom’s negative ion (ground state)
What is the effective nuclear charge and what is its impact?
The postitive charge that an electron experiences from the nucleus, equal to the nuclear charge but reduced by any shielding or screening from any interveining electron distribution.
Increasing the effective nuclear charge reduces the size of the orbital.
