WEEK3 Flashcards
What is electron configuration?
The electron configuration of an element describes how electrons are distributed in its atomic orbitals. They follow a sequence in which all electron containing atomic sub-shells are placed in a sequence.
what is electron configuration for sodium
1S2,2S2,2P6,3S1
An alternative way of writing electron configuration is by using the symbol of..?
Noble gasses
Write the electronic configuration for sodium, aluminium and calcium using the symbol of noble gasses
Al: [Ne]3s2,2p1
write the electron configuration for the first 10 elements (include noble gas notation)
refer to lecture o1c
what is the maximum number of electrons that can by held by each shell, n=1, n=2, n=3, n=4
2, 8, 18, 32
what is the maximum number of electrons that can be held by each subshell, l=0, l=1, l=2, l=3. s,p,d,f
2, 6, 10, 14 respectively
what is the Aufbau principle?
Electrons will occupy orbitals having lower energy first before higher energy orbitals
State the Pauli Exclusion Principle
- a maximum number of two electrons each having opposite spins, can fill an orbital
-if the principle, azimuthal and magnetic numbers are the same for two electrons, they must have opposite spin.
Hund’s Rule
States that every orbital in a given sub-shell is singly occupied by electrons before a second electron is filled in an orbital
How is the Periodic Table ordered?
Elements are ordered according to their increasing atomic number
Who arranged the periodic table?
Dmitri Mendeleev
What do horizontal rows represent?
Periods
-Each period is assigned a number 1 - 7 indicating the principle quantum number
what do vertical columns represent?
groups (families) each group is assigned a number from 1 to 18 indicating the number electrons in their outer most shell
What does each row(period) represent?
A new Electron shell. Therefore; elements in the same period have the same number of shells
What do elements in the same vertical column (group) have in common?
They have the same number of valence electrons and have similar propertis
Each period is assigned a number (1to7. what quantum number does this indicate
principle quantum number (n)
each group is assigned a number (1through18). what does this indicate?
The number of valence electrons in the outermost energy level of its element
What are group 1 elements? describe their properties.
Alkali metals: Highly reactive metals, soft, low melting points
What are group 2 elements? describe their properties
Alkaline Earth Metals: Reactive metals, less reactive than alkali metals
What are group 17 elements?
Halogens: Highly reactive nonmetals, form salt with metals
What is group 18?
Noble gasses-inert, non-reactive gasses with full valence shells
Transition Metals
- starting from fourth period, 10 transition elements per period occupy the central part of the table
- because of the presence of d-orbitals the vertical columns of these elements are called B-groups
Lanthanides and Actinides
-have electrons in the f orbital
-14 elements per series
