Atomic Theory
How many electrons can fit into the second electron shell of the Bohr model?
8 electrons in n=2
What is a valence electron?
An electron in the outermost shell of an atom.
Vertical columns are called...
Groups
What is the electronegativity trend across/down the table?
Increases across, decreases down
Name the four subshells of the Quantum Mechanical Model and the number of electrons that fit into each.
s = 2, p=6, d=10, f=14
What is the Aufbau principle?
Electrons fill shells in order of the shell energy level (lowest energy shells first)
The name of Group 1 elements
Alkali metals
Increases across and up the table.
Explain why a nucleus needs neutrons.
Neutrons stabilise the nucleus (protons are a ton of positive charge)
What is hund's rule?
Bus seat rule - every orbital in a subshell (eg. p=3) must be singly occupied before it can be doubly occupied by another electron.
The name of group 18 elements.
Noble Gases
Explain why atomic radius decreases across the periodic table even though more electrons are being added.
The increased amount of positive charge from the nucleus and increased negative charge of the electrons results in more attraction between the electrons and the nucleus. The effective nuclear charge between the nucleus and valence electrons is greater.
What is the order that electrons fill subshells, up to 5s?
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2
Electron configuration of Oxygen?
1s22s22p4
Transition metals are also called...
d block elements
Explain the trend of electronegativity across a period.
Atoms on the right of the periodic table have a higher effective nuclear charge, so electronegativity increases across a period.
Which two elements are exceptions to the Aufbau principle?
Copper and chromium
Condensed electron configuration of Magnesium?
[Ne]3s2
In a group 17 halogen, which quantum block is currently being filled?
p block
Which ion is larger: F- or Mg2+
Fluorine is larger because although the electron configuration is the same, magnesium has more protons and therefore has a greater effective nuclear charge than fluorine, pulling electrons in more tightly.