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Chem 11/13-11/26
Question | Answer |
---|---|
What did Mendeleev do? | is credited for the Periodic Table |
Why was Mendeleev given credit? (4 reasons) | 1.sorted the known elements into groups based on their chemical properties 2.left spaces for new elements 3.accurately predicted 3 new elements and their physical and chemical properties 4.knew that using atomic masses to order elements was incorrect |
What did Mendeleev name three elements that he predicted would exist? | eka-Silicon, eka-Aluminum, eka-Boron |
What is Periodic Law? | physical and chemical properties periodically repeat according to atomic number |
What are the Representative Elements? | the s and p blocks on the P. T. |
what are the Transition elements? | the d block on the P.T. |
Where are the metals located on the periodic table? | left of the Boring Staircase |
Where are the nonmetals? | right of the metalloids |
Name the metalloids (8) and where they're located | B, Al, Si, Ge, As, Sb, Te, Po, on the Boring staircase |
What are Diatomic elements? Name the 7 elements that are diatomic. | elements that are stable only when paired in twos. H,N,O,Fl,Cl,Br,I |
Where are the Alkali Metals? | first column on left |
Where are the Alkaline Earth Metals? | to the right of the alkali metals |
Where are the noble gases? | first column on the right |
Where are the halogens? | to the left of the noble gases |
Where are the chalcogens? | to the left of the halogens |
Describe and explain the trends of atomic radius | atom size shrinks as more protons are in the nucleus because of a greater pull on fewer valence electrons. L->R: atoms get smaller, TOP->BOTTOM: atoms get larger due to shielding effect |
What is an ion? | charged atom due to the loss or gain of electrons |
What is a cation? | loss of electrons, positively charged ion |
What is an anion? | gain of electrons, negatively charged ion |
Describe and explain the trends of ionic radius | depending on which noble gas an element is closest to, it can either gain or lose electrons in order to gain stability in the form of a noble gas. from L->R: size decreases, from TOP->BOTTOM: size increases (because it gains more M.E.L.s as you go down) |
Describe and explain the trends of ionization energy | L->R: energy increases because the number of p+ in the nucleus increase and make atom smaller, which increase the atomic pull on electrons. TOP->BOTTOM: decreases, as you go down there are more layers of electrons, which increases the shielding effect |
Describe and explain the trends in electronegativity | L->R: decreases then increases because elements become worse at sharing electrons because they hold e- closer to the nucleus, TOP->BOTTOM: decreases because they have more MEL's, shielding effect |
Define electronegativity | the ability of an atom to attract electrons |
define the shielding effect | describes the attraction between an electron and its nucleus when there are more than one layer |
define electron affinity | amount of energy to take an electron off from a neutral atom |
describe and explain electron affinity trends | from L->R: decreases then increases because elements on the left side gain an electron and are pushed away from being stable, elements on right side release more energy because they need more electrons to be stable |
What are the inner transition elements? | f block of periodic table |
what is ionization energy? | the amount of energy required to move the first electron from an atom |
what property did Mendeleev use to organize the periodic table? | increasing atomic mass |
What is atomic radius? | 1/2 the distance between two nuclei of the same element when they are bonded together |
Sketch the periodic table and show the following trends: ionic radii, atomic radii, ionization energy, electron affinity, electronegativities |