patterns in periodic table – Flashcards
Unlock all answers in this set
Unlock answers| how are elements in the same period arranged? |
Each sequential element has one more proton and one electron
(as you go from left to right) |
| how are elements in the same group related ? |
| they have a same valence config & have similar chemical properties |
| grp 1A is called |
| alkali metals |
| grp 2a is called |
| alkali earth metals |
| B,Si,Ge, As,Sb,Te,Po are called |
| metalloids |
| C,N,O,P,S,Se are called |
| non metals |
| Grp 7A are called? |
| halogens |
| Grp 8A is called |
| inert(noble) gases |
| effective nuclear charge def |
as the nucleus becomes ↑ positive, all electrons experience a stronger pull toward the center.
"how strong a particular element pulls electrons" |
| Why do cations vs (anions /neutral) have a higher effective nuclear charge? |
cations: have more protons than electrons, therefore they are strongly attracted to electrons (aka they really want to get rid of their positive charge).
anions: have more elecs will have a slightly lower effective nuclear charge.
neutral: have an equal # of protons and elecs (have the lowest eff. nuc charge) |
Who has a larger effective nuclear charge(Zeff): Na or Mg? |
Mg effective nuclear charge increaes as you go across elements in the same period. |
Who will have a bigger prinicipal quantum number H or Fr? whos electrtons will be held less tightly? |
Fr ; as you go DOWN a grp prinicipal quantum number increases its valence e- will be held less tightly to nucleus
|
| Tell who has a bigger atomic radius K or Mn? |
K ; atomic radii decreases as you go across a period (recall zeff increases) |
| Ionization energy/potential (IE) def |
energy required to remove an electron from a gaseous atom or ion
(this requires energy (endothermic)) |
If the effective nuclear charge is high : describe the location of the valence e- the ionization energy the electron affinity
|
high zeff= valence e- tightly bound to nucleus HIGH ionization energy HIGH electron affinity
(aka it takes it alot energy to remove these electrons) |
| Why is the second ionization energy always higher than the 1st ionization energy? |
Recall an element doesn't want to have a postive charge it wants to gain e- in order to have a full octet, so it takes alot more energy to remove the 2nd e- ;b/c the element is becoming increasingly positive. |
Why do grps 1 ; 2 have low electron affinties? Why do grp 7 have high? |
grps 1 ; 2 (alkali metals ;alkali earth metals) need to lose 1 or 2 e- to achieve their octet. grp 7 (halogens): only need to gain 1 more e- to achieve their octet so they are the greediest. |
electron affinity def electronegativity def |
1.energy released when atom recieves an electron *(remember if an element is closer to its octet its energy will be lower hence released , that is a very good thing) ; 2. is a measure of the attractive force that an atom will excert in an electron in a chemical bond, aka its attraction for bonding electrons |
| what is another name for electronegativity? |
| nuclear positivity |
| True or False: metals have a low density ; high melting points |
metals have a high density high melting point |
For metals in general give high/low for the following: zeff;(effective nuclear charge) electronegativity atomic radius ionization energy |
;zeff;(effective nuclear charge) ;electronegativity ;atomic radius ;ionization energy |
| ;What do the previous characterisitcs allow metals to do? |
| donate one or more electrons |
| Why are metals good conductors of heat and electricity? |
| their valence electrons are not bound tightly, they can move freely. |
|
zeff;(effective nuclear charge) ;electronegativity,electron affinity ;atomic radius ;ionization energy |
True or False: Non metals are good conductors of electricity and heat |
| false |
| Which metals are the most reactive? |
| alkali and alkali earth |
| alkali metals typically have an oxidation state of? |
+1 (they often lose 1 e- to complete their octet) |
| what is the oxidation state of alkaline earth metals |
+2 (they like to lose 2 electrons in order to complete their 'octet') "full outer shell" |
| halogen oxidation state |
-1 (prefer to gain 1 e- to complete their octet) *remember they have 7 electrons |
| true or false: halogens have the highest electronegativities |
| yes, remember they only need one more e- to complete their octet |
Noble gases: Why are they stable? tell high/low: ionization energy electronegativites |
their valence shell is complete (8e-) ; ;ionization energy almost zero ;electronegativites |
describe the oxidation states of transition metals give 2 ex |
transition metals have many positive oxidation states Fe: +1 ,+2 Mn: +2,+3,+6,+7 |
| transition metals have many positive oxidation states, what does this allow them to do? |
form many differnt ionic compounds ex hydration complexes (water) highly colored solutes and compounds(enchances the low solubility of some compounds); |
| hemogloblin has what significance regarding this chapter? |
| hemogloblin features Fe which changes it state in order to carry out its fcn. |
Why does P have a lower electron affinity than Si? (this goes agaist the periodic table trend ) |
P's electronegativity gives a very stable half filled p oribital vs Si only needs 1 more electron to fill its p orbital and therefore is very greedy. |
| the grp next to the halogens is called |
| chalogen |
which will have a bigger atomic radius? anion or cation vs a neutral atom |
K- (bigger) than K b/c its has gained more e- |
