Chem Lesson 3

Periods

7 rows

Groups

18 columns

Alkali metals are group blank

1

Alkaline earth metals are group blank

2

Halogens are group blank

17

Noble gases are group blank

18

Metals

Shiny, malleable, conduct heat/electricity

Nonmetals

dull, bad conductors

Metalloids

Properties of metals and nonmetals

Representative elements are groups blank

1, 2, 13-18

Transition metals are groups blank

3-12

Inner-transition metals are groups

below main periodic table

Rutherford atom

Smallest particle of element, dense. Has nucleus w/ protons/neutrons, electron cloud w/ electrons w/ specific orbits

Orbit

Specific energy level

Atomic # (z)

# of protons in nucleus

Do elements share atomic numbers

No, unique to each element

The periodic table is arranged by blank atomic number

increasing

Neutral atom

# of protons = # of electrons

Mass # (A)

Protons + neutrons

Neutrons

A - Z

Is A on the PT

No, unique to each isotope

Can A be a fraction

No, always a whole number

Isotope

Same element with different # of neutrons (same Z, diff A). Same # of electrons

Are most elements 1 isotope, or a mix?

A mix

Isotopic notation

Element - A

Atomic weight

Weighted average of naturally occurring isotopes per element. On PT

The atomic weight shows the blank of the element

abundance

Principal Quantum # symbol

n

n

energy level of orbital

Angular momentum # symbol

L (lowercase)

L (lowercase)

orbital’s shape

Magnetic Quantum # symbol

M subscript L

M subscript L

Orientation of orbital in space

n is an integer between

1 and 7

Is inter-shell spacing uniform?

No

Higher n is blank energy level

Higher

1st shell

Closest to nucleus, lower energy and hard to remove

Outermost shell

Valence electrons, most chemical reactions occur here

L (lowercase) can be an integer between

0 and (n-1), max value 3

What is L (lowercase) used for

Bonding

L=0

s orbital

s orbital

1 sphere

L=1

p orbital

p orbital

2 spheres

L=2

d orbital

d orbital

4 spheres

L=3

f orbital

f orbital

Complex

Subshells

Orbitals with same L value

Do the electrons within each subshell (s,p,d,f) have the same energy?

yes

# of subshells within energy shell

n (principal quantum #)

Does s have the highest or lowest energy?

Lowest

A higher size orbital = blank value shell

higher

m subscript L

Orientation of orbital within subshell

M subscript L is an integer between

-L and +L

Do m subscript Ls have common orbital orientations?

No, each unique

L=0

1 s, m subscript L is 0

L=1

3 p, m subscript L can be -1, 0, 1

L=2

5 d, m subscript L can be -2, -1, 0, 1, 2

L=3

7 f, m subscript L can be -3, -2, -1, 0, 1, 2, 3

Spin quantum # symbol

m subscript s

m subscript s

+1/2, -1/2

Pauli Exclusion Principle

No 2 electrons in same atom can have same set of quantum #s, must have opposite spins, no more than 2 electrons in same orbital

Electron configurations

List shells/subshells in order of increasing n, subshell, # of electrons in subshell

Aufbau principle

Electrons fill orbitals in order of increasing energy

Abbreviated electron configuration: noble gas in brackets

represents core electrons, then list electrons in sublevels in order of filling

Core electrons

Electrons in inner increasing energy levels, no chem. bonding, shield nucleus from valence electrons

Orbital diagrams: pairing of electrons represented as

arrows

orbital diagrams: boxes based on

orbitals in sublevel

orbital diagrams: s

1

orbital diagrams: p

3

orbital diagrams: d

5

orbital diagrams: f

7

Hund’s rule

fill each box with one arrow before putting 2 in any box

Electrons can share orbital ONLY with

different m numbers

Electrons in the same group have similar blank, giving them similar chemical reactivity

valence electrons

Last added element in representative elements enters what orbitals in outer shell

s or p

Representative elements groups

1, 2, 13-18

last added electron in transition metals enters which orbital

d

transition metals groups

3-12

Last added electron in inner-transition metals enters which orbital

f

inner-transition metals groups

3-12

Ions

Atoms that have gained/lost electrons

Why are ions formed

for a stable valence shell

Cation

+ charge, lost electrons

Anions

- charge, gained ions

Representative cations: electrons removed

Electrons moved from highest energy orbitals first

Transition/inner transition cations: electrons removed

Highest energy levels, then from (n-1) or (n-2) subshell

Anions

electrons added to highest energy orbitals to form octet with 8 valence electrons

Charge of group 5A

+ 3 electrons, NEGATIVE 3 charge

Atomic radius

represents distance from nucleus to valence electrons

Atomic radius periodic trend

decreases across period, increases across group

Ionic radius

Distance from ion’s nucleus to valence electrons

Cations: ionic radius

smaller

Anions: atomic radius

bigger

Ionization energy

Minimum energy required to remove valence electrons from atom in gaseous state

2nd ionization

remove 2nd valence electron

Lower ionization energy means it is blank to remove electron

easier

Ionization energy trends

Increases across period, decreases across group.

Ionization energy blank as atomic radius increases

decreases