(this is from last lesson but still relevant) when writing out lewis dot structures for ions, what should you do to indicate that it's for an ion?
you should write the little +n/-n superscript in the upper right hand corner to indicate that it's an ion and why it's different than the "normal" element's lewis dot structure
what did johann dobereiner do for a living? what did he do to impact and influence the periodic table?
he was a german chemist who grouped the known 49 elements into triads (ex: calcium, barium, and strontium - strontium's mass is half of the combination of calcium's and barium's masses) based on those with similar properties and that reacted similarly to things
what did dmitri mendeleev do for a living? how did he impact and influence the periodic table (multiple things)?
he was a russian chemist who grouped elements together according to their similar properties (in columns) and arranged the elements according to their atomic masses
in mendeleev's time, how many elements were there? why did he leave some blank spaces, and were those spaces eventually filled?
there were 49 elements in his time, and he left some blank spaces because nothing fit in them in terms of similar properties or atomic mass; he determined that there were other elements that weren't discovered yet that should go in those spaces... and he was right
was mendeleev 100% correct in where he placed all of the elements on the periodic table?
no, there were a few that weren't in the correct columns according to their properties, but we fixed em
who determined the reason a few of the elements were mismatched on the periodic table, and was given credit for making the real, first periodic table? what else did they discover, which led to a rearrangement of some elements?
henry moseley; he also discovered the positive charge was the element's atomic number and arranged the periodic table according to them
was moseley's periodic table perfect?
no there were a few tiny discrepancies, like the fact that terbium and antimony's masses are a little off, but it is mostly pretty correct
periodic law
the properties of the elements are a periodic function of their atomic numbers
in the modern periodic table, what are groups? what are periods?
groups are vertical columns of elements in the periodic table and periods are horizontal rows of elements in the periodic table
how do elements in the same group compare to each other?
all elements in the same group have similar chemical properties and valance electrons
for example, how to all elements in group 1A react to water, to show how similar they are? why do they do so?
they all react vigorously to water; lithium, sodium, potassium, etc. all act very violently with water, since their electron levels are like 4 or 5 as the group goes down, so the nucleus doesn't have as much of a handle on the electrons in the outer level and don't have as much of a problem giving them up and reacting to things as elements with only one or two energy levels; so even though elements further down in the group may be just a tad more violent when reacting with water, they all are pretty reactive, which shows that elements within a group do, indeed, have similar properties
what do periods aid in dictating?
the energy level
what do columns 1A-7A (group 2A included) have in common? what type of elements are they?
they all have incomplete s and p subshells; representative elements
what do all elements in B columns/d block have in common? what type of elements are they?
a d subshell is being filled in all of them; transition elements
which lanthanide element is included as a transition/d block element? which actinide element is the same?
lutetium; lawrencium
what do all elements on the bottom of the periodic table in 4f and 5f have in common? what type of elements are they?
an f subshell is being filled in all of them; inner-transition elements
what are the four main column titles?
alkali metals, alkaline earth metals, halogens, and noble gases
which groups are considered alkali metals? what do PEL do they end in?
all elements in group 1A; s^1
which element within group 1A isn't an alkali metal? what is it, instead?
hydrogen; a nonmetal
which groups are considered alkaline earth metals? what do PEL do they end in?
all elements in group 2A; s^2
which groups are considered halogens? what do PEL do they end in?
all elements in group 7A; s^2p^5
what do compounds with halogens in them create?
salts
which groups and extra element are considered noble gases? what do PEL do they end in?
all elements in group 8A and Helium; s^2p^6
what are noble gases?
inert gases (meaning, since they have full outer valence shells, they don't generally react to anything)
which "special" group of elements are the most reactive? which element within that group is the absolute most reactive element on the entire periodic table?
halogens; fluorine
what are the 7 metalloids on the periodic table?
boron, silicon, arsenic, terbium, germanium, antimony, and astatine (NOT POLONIUM)
which part of the f block - 4f or 5f - are lanthanides? actinides?
lanthanides = 4factinides = 5f