Match the following descriptions to the person they describe: Mendeleev or Moseley.
|Mendeleev||arranged elements according to atomic mass|
|Mendeleev||predicted properties for elements missing from his periodic table|
|Moseley||English physicist, used x-ray diffraction|
|Mendeleev||had some elements out of place|
|Moseley||arranged elements according to atomic number|
|Moseley||discovered that each element has a unique atomic number|
|Mendeleev||Russian chemist, created first valid periodic table of the elements|
|Moseley||placed all elements in the right place according to properties|
What property is identical to the elements in each column of the periodic table?
Click to reveal the answer
Electron distribution – each element’s last term has the same number of electrons located in the same type of sublevel.
Li = 2s¹
Na = 3s¹
K = 4s¹
Write the noble gas configuration for each of the following elements. Highlight the table to reveal the answers.
|Copper||Copper doesn’t follow the rules as expected. [Ar]4s13d10|
|Silver||Silver does not follow the rules as expected. [Kr]5s14d10 is the actual configuration. One 5s electron moves to the higher 4d sublevel because it is more stable there.|
(Hint: don’t forget the f-block!)
|[Rn]7s25f4 Remember that the principal quantam number is 2 fewer than the period number for electrons in f sublevels.|