chap 5 review

grouped elements with similar properties first periodic table created by

Dmitri Mendeleev

who arranged periodic table together in order of increasing atomic number?

Henry Moseley

metals are located on which side of periodic table

left (exception:hydrogen)

characteristics of metals

-ductile
-malleable
good conductors of heat and electricity
high melting points (except for Mercury)

nonmetals located on

right side of periodic table (C, P, S I ,Se=solids at room temp)

metalloids

staircase seperates nonmetals from metals

if element is a good conductor of heat but brittle it is

a metalloid

alkali metals melting point

-lowest melting point

which one can you cut w a knife?

alkali metals

moving down a group, metallic character becomes stronger for?

alkali metals and alkaline earth metals

alkaline earth metals melting point?

higher melting point than alkali metals

what is very reactive with water?

alkaline earth metals

what is the exception with reaction of water with these 2 elements?

Be=no reaction
Mg= will react with steam

transition metals melting point is

high melting point and much less reactive than alkali metals

characteristics of transition metal

ductile and malleable

moving down group for transition metal, metallic character becomes

stronger

oxygen group metallic character increases going down or decreases

increases

O=

nonmetal

Te=

metalloid

Po=

metal

halogens are the most reactive...

nonmetals

which is the most reactive nonmetal for the halogens?

Flourine (F)

what is reactivity based on for halogens?

7 electrons in outer shell, wanting one more electron to fill octet

are noble gases reactive?

no because s and p shells are compeltely filled in

lanthinides
+ actinides are

metals, very reactive

are lanthinides or actinides radioactive?

actinides

Zeff is

charge experienced by an electron on a many-electron atom

going across periodic table, Zeff

increases

why does Zeff increase going across a period?

because more valence e- added while screening e- does not increase

going down periodic table, Zeff

increases slightly

put following elements in order of increasing Zeff: Be, Ca, Sr, Mg

Be

atomic radii across table

decreases

why does atomic radius decrease going across table?

bc as more e- added, nucleus pulls those e- closer, decreasing atom size

going down table, atomic radius

increases

why does atomic radius increase going down periodic table?

bc more shells added going down, increasing atom size

put elements in order of increasing atomic radius: Be, C, K, Ca

C

Ionization energy is

energy required to remove one e- from a neutral atom of element

when e- removed or gained we create an

ion

across table IE

increases

why does IE increase across table?

bc more energy is required to remove e-

going down table, IE

decreases

why does IE decrease going down table?

bc less energy required to remove an e- bc they are farther from the nucleus

removing more e-, increases or decreases IE?

increases

put following elements in order according to IE: Be, C, K, Ca

K

Electron affintiy is

energy change when one e- is added to a neutral atom of element (Na + e-) = Na-

moving across, EA

increases

why does EA increases across period

increase in # of val e- , elements want to have full octet

going down, EA

decreases

why does EA decrease going down a group?`

e- further away from nucleus due to increasing atomic radii

which element has highest e- affintiy?

fluorine

put elements in order of increasing EA: Be, C, K, Ca

K

Ionic Radii has

cation (+)
anion (-)

is a cation bigger than its parent atom?

smaller bc e- removed making e- cloud smaller

is anion bigger than its parent atom?

bigger bc e- gained, increasing radius

which of following atoms or ions bigger? Ca or Ca^2+

Ca

S or S^- bigger?

S^-

Electronegativity is

ability of atom in chemical compound to attract e-

most electronegative compound

Flourine

moving across table, electrongeativty

increases

why does electroneg increase across table

charge on nucleus increases which attracts more e-

moving down table, electroneg

decreases

why does electroneg decrease going down table

bc size of atom increases , so e- cannot be pulled as close

put following elements in order of increasing electroneg: F, As, Sn, S

Sn

Octet Rule

atoms lose/gain/share e- to get to 8 val e-

if F wants to get 8 val e- how many e- does it need to gain?

1

if Mg wants to get 8 val e- how many e- does it need to lose?

2

smallest atomic radius=

noble gases

which group have largest atomic radii

metals

atomic radii cannot be measured directly bc electron cloud surrounding the nucleus does not have a clearly defined (charge, mass, outer edge, probability)

outer edge

atom becomes negatively charged when an electron is

gained

difference between electroneg + ea

ea gains e-
electroneg ability to attract e- from other atom