Chemistry Chp 5
what colors are often ascociated woth these metals: -copper -cadmium -cobalt -zinc -nickel
-blue -yellow -pink -white -green
how many groups are in the periodic table?
18
how many periods are in the periodic table?
7
Created a table in which elements with similar properties were grouped together- a periodic table of elements (atomic mass)
Dmitri Mendeleev
the most active element in group 17
Flourine
Which elements are designated as the alkali metals?
Group 1 (lithium, sodium, potassium, rubidium, cesium, francium)
Which elements are designated as the alkaline earth metals?
Group 2 (beryllium, magnesium, calcium, strontium, barium, radium)
Arranged elements by their atomic numbers
Henry Moseley
What are some characteristic properties of alkali metals?
Silvery, soft enough to cut with a knife, reactive, stored under kerosene, boiling point is very low
Enabled chemists to agree on standard values for atomic mass and initiated a search for relationships between atomic masses and other properties of the elements
Stanislao Canizzaro
What determines the length of each period in the periodic table?
The number of electrons that can occupy the sublevels being filled in that period
How do the electron configurations within the same group of elements compare?
They all have the same outer electron configuration
Why are the noble gases relatively unreactive?
They have all 8 electrons
How is the periodic law demonstrated within the groups of the periodic table?
When the elements are arranged in order of increasing atomic number, elements with similar properties appear at regular intervals
elements of group 2 are called-
alkalin earth metals
elements of group 1 are called-
alkalin metals
distinguish between a cation and an anion. How does the size of each compare with the size of the neutral atom from which it is formed?
cation is positive- decreases (smaller) anion is negative- increases (bigger)
what sublevels are filling across the transition elements?
d & f
as you go from left to right across a period, the atomic size decreases or increases? why?
decreases bc it will have an increased net positive charge
as you go down a group, the first ionization energy generally decreases or increases? why?
decreases, addition of shells and further away
where is the highest electronegativity found?
far upper right hand corner
what tramsition elements are considered noble metals?
gold, silver, platinum, pladium
what types of elements make up p block?
group 13-18 except helium, metals, nonmetals, metalloids
which elements are the halogens?
group 17 flourine, chlorine, bromine, iodine, astatine,
what are the noble gases?
group 18- helium, neon, argon, krypton, xenon, radon
group 17 elements are called-
halogens
how do the characteristic properties of alkaline earth metals compare with those of alkali metals?
harder than alkali metals, higher melting point, less reactive than alkali metals but are still reactive and found in nature
where are valence electrons located?
incompletely filled main energy levels
how do the first ionization energies of main group elements vary across a period and down a group?
increase across a perios bc there are more protons pulling on the electrons, decrease down a group bc there are more shells so they are farther away from the nucleus
as you go from left to right across a period, the first ionization energy generalky decreases or increases? why?
increases, increase net positive charge
as you travel down a group, the atomic size decreases or increases? why?
increases, more energy levels
elements in the periodic table are arranged according to their____
increasing atomic number
why is flourine special in terms of electronegativity
it is the most electronegtive element 4 ( highest you can have)
a negative ion is smaller or larger than its parent atom
larger
what are trhe characteristics of a noble metal?
low reactivity
where are the most active metals located?
lower left hand corner
where is the lowest electronegativity found?
lower left hand corner, francium
an element with both metallic and nonmetallic properties is called a____
metalloid; semi metal
the majority of elements in the periodic are____
metals
as you go from left to right across the periodic table, the elements go from metals or nonmetals to metals or nonmetals?
metals to nonmetals
as you go down a group, the elements generally become___ metallic
more
group 18 elements are called-
noble gases
what are the main group elements
p and s block
which two blocks of the periodic table make up the main group elements?
p and s block
how do the properties of the p block metals compare with those of the metals in the s and d blocks?
p is usually harder than s but softer than d
elements across a series have the same number of____
principle energy level
what gems contain chromiun impurities?
rubies
a positive ion is smaller or larger than its parent atom
smaller
what trend is observed among the atomic radii of main group elements down a group?
the atomic radii increases down a group because you are adding shells
what trend is observed among the atomic radii of main group elements across a period?
the trend to smaller atoms across a period is caused by the increasing positive charge of the nucleus
what is the most significant property of the noble gases?
they have a full outer shell
a colored ion generally indicates a ____
transition element
elements of group 3-12 are called-
transition elements
what name is sometimes used to refer to the entire set of d block elements?
transition elements
where are the most active nonmetals located
upper right hand corner
elements within a group have a similar number of____
valence electrons
which elements are the f block?
wedged between groups 3 and 4 in the 6th and 7th period
what colors are exhibited by chromium in its common oxidation states?
yellow, violet