Atomic radii
1/2 the distance between the nuclei of identical atoms that are bonded together
Period- atoms get smaller b/c of increasing + charge of the nucleus
Group- atoms get larger b/c of increase of energy levels as you go down
What happens to the period trend and group trend for atomic radii?
Ionization energy
The energy required to remove one electron from a neutral atom of an element
Period- increase b/c of increasing nuclear charge, higher charge more strongly attracts e- in same energy level
Group- decreased b/c increase of energy levels, the e- are further from the nucleus and therefor easier to remove
What happens to the period trend and group trend for ionization energy?
Electron affinity
The energy change that across when an electron is gained by a neutral atom
Period- increase b/c number becomes more - b/c energy gives off a negative value
Group- decreases b/c e- are added with greater difficulty due to 1. slight increase in nuclear charge 2. Increase in atomic radii
What happens to the period trend and group trend for electron affinity?
Electronegativity
A measure of the ability of an atom in a chemical compound to allow e- from another atom in the compound
Period- increase b/c more + nucleus
Group- decrease b/c shielding effect
What happens to the period trend and group trend for electronegativity?
Ionic radii
Size of ions
Period- cations (metals on left) & anions (nonmetals on right) decrease b/c of + nucleus
Group- increase due to adding energy
What happens to the period trend and group trend for ionic radii?
An atom gets larger as the number of electronic shells increase
Why do atoms get larger as you move down a group/family but smaller as you go across a period?
Ion
An atom or group of bonded atoms that has a + or - charge
Cation
Positive ion (lose e-)
Decrease in size because more p+ so pull closer together
Anion
Negative ion (gain e-)
Increase in size because more e- so don’t pull as close together; e- repel each other so they spread out
Valence electrons
The e- in the outer most energy level available to be lost, gained, or shared in the formation
Fluorine
What is the most electronegative element and given a value of 4.0
True
When atoms become ions, their radii change t/f
Ionization
Any process that results in the formation of an ion
Outermost s&p sublevels
For main group elements’ valence e-, where are they located?
Held tightly to nucleus
Why aren’t the inner e- involved in the valence shell?
False (outer)
Only inner shell e- are involved in forming compounds
E- are lost, gained or shared
How are chemical compounds formed?
Cannizzaro
…… is credited with developing a method that led to the determination of relative atomic mass
Mendeleev; atomic mass
… organized elements on the periodic table according to their increasing …
atomic number; Moseley
The modern periodic table is now arranged in order of increasing ….. …… This was established by …..
modern periodic law; atomic number
The ….. ….. …. states that the physical and chemical properties of the elements are periodic functions of their ……. …..
alkali metals
alkaline earth metals
What groups are in s-block?
halogens
metalloids
noble gases
other nonmetals
other metals
What groups are in p-block?
transition metals
What groups are in d-block?
lanthanides
actinides
What groups are in f-block?
alkali metals
alkaline earth metals
What groups are too reactive to be found as a free element in nature?
lanthanides
What group elements are shiny metals and similar to the reactivity of group 2 elements?
largely unreactive
What is the most distinctive property of the noble gases is that they are…..
group
The discovery of the noble gases changed Mendeleev’s periodic table by adding a new….
modern periodic law
the physical and chemical properties of an element are functions of its atomic number
alkali metals
silvery appearance
soft enough to cut with knife
very reactive, must be stored in kerosene b/c they will react the water in the air
not found in nature as free elements, only in compounds
alkaline- earth metals
harder, denser, & stronger than alkali metals
higher boiling point
less reactive but also not found in nature as a free element
H & He
unique, does not share the same properties of Group 1
transition metals
metals w/ typical metallic properties
good conductors, high luster
typically less reactive than alkali and alkaline-earth metals
some so nonreactive they do not easily form a compounds & exist as free elements (gold, platinum, palladium are the least reactive)
halogens
most reactive nonmetals
react very vigorously with most metals form salts
metalloids
semiconducting elements
located in p-block with metals and nonmetals
metals of the p-block
harder & denser than the s-block metals, but softer than the d-block metals
lanthanides
shiny and similar to group 2 reactively
actinides
radioactive and only 1st four found naturally on earth, the rest made in the lab
main group elements
the p-block elements along w/ s-block elements
rt. hand side = metals
lt. side & bottom = nonmetals
middle = 6 metalloids (B, Si, Ge, As, Sb, Te)