Chemistry - Quantum Theory and electron configuration

What is an orbital?

3-D region where an electron can be found

What does the principal quantum number describe?

energy level of the atom

What is the principal quantum number also called?

the shell, n

What does the angular momentum quantum number describe?

the shape

What is the angular quantum number also called?

sub-shell, l

What does the magnetic quantum number describe?

m_l, describes the orientation of an orbital in space

What does the spin quantum number describe?

the spin of the electron, m_s

What can the principal quantum number value be

any positive whole number

What can the value for the angular momentum quantum number value be?

positive whole numbers and zero/ spdfg…

What can the value for the magnetic quantum number be?

0… to +- l

What can the spin quantum number value be?

m_s=+- 1/2

Write the electron configuration for Maganese:

1s²2s²2p⁶3s²3p⁶4s²3d⁵/ [Ar]4s²3d⁵

Draw the electron configuration according to Hund’s rule for Manganese:

ꜛꜛꜛꜛꜛ

Label the periodic table with SPDF

What’s [Ar]4s²3d^6’s atomic symbol?

Fe

Give the atomic symbol of the element with 4 3p electrons as last electrons added

S

Ten electrons in the n=4, l=2 sublevel

Cd

How many 3p electrons does copper have?

6

What’re the exceptions to Hund’s Law?

Cr and Cu

Why does the periodic table have its characteristic shape?

groups/ families have shared characteristics

What is periodic law?

when chemical elements are arranged in order of increasing atomic number, their physical and chemical properties show a predictable, repeating pattern

What’re the properties of metals?

• malleable and ductile

• shiny, lustrous, and reflect light

• conduct heat and electricity

• most oxides are basic and ionic

• forms cations in solutions

• lose electrons in reactions (becomes positively charged)

What’re the properties of nonmetals?

• brittle when solid

• dull

• electrical and thermal insulators

• most oxides are acidic and molecular

• forms anions and polyatomic anions

• gains electrons in reactions (becomes negatively charged)

What explains Mendeleev’s periodic law?

electron waves

What’s the trend in atomic size?

Bottom left increases atomic radius

Why does the atomic radius decrease when going from left to right on the periodic table?

nucleus has more positive protons that have more attraction to the negative electrons (opposites attract)

What are valence electrons?

electrons with the highest principal energy shells / electrons on the outermost shell

What are core electrons?

electrons on lower shells

What're the key factors in predicting the chemical and physical properties of elements?

the number of valence electrons

Elements in the main groups have the same ______ as the group number

valence electrons

What does the Bohr model accurately predict?

The spectrum of hydrogen and 1 electron ions

Where does the Bohr model fail?

when it’s applied to multiple electron atoms

• it can’t account for interactions between electrons

• it doesn’t explain why only certain energies are allowed

• it doesn’t explain why the electron doesn’t crash into the nucleus

What’s wave-particle duality?

Electrons have the characteristics of particles and waves at the same time.

What is an orbital?

Electron-waves

What can be associated with the physical properties of electrons?

Electron waves

• De Broglie proposed that electrons (and all matter) have the properties of waves

  • The electron-wave (or orbital) is described by an equation related to the electron’s probable location

What is the orbital described as?

a wave function

What is the probability of where the electron is?

square of the function

What does this image represent?

the probable distribution of a wave function

What’re the modifications to Bohr’s diagram?

Replace the linear orbits of the Bohr model with waves (called orbitals)Wh

What is the radial node?

Where there’s no chance of finding an electron

For 1D standing waves, what’re the trends as energy increases?

Energy increases from n=1→ 4