test 6 the periodic table Flashcards
Mendeleev
father of periodic table
arranged elements according to atomic mass
noticed pattern in the properties of elements
had gaps in his periodic table
Moseley
1909
arranged the elements according to increasing atomic number and gaps disappeared
period
a horizontal row, there are 7, each ends with a noble gas
what does each period number indicate
number of occupied energy levels
group
vertical column
also called families
8 with Roman numerals and 18 with numbers
elements in a group have
similar chemical properties
group number indicates
the number of valence electrons
group IA is
alkali metals
group IIA is
alkaline metals
group IIIA is
Boron group
group IVA is
carbon group
group VA is
Nitrogen group
group VIIA is
Halogens
group VIIIA is
Noble Gases
group number indicates
number of valence electrons
maximum nmber of valence electrons
8
helium has how many VE
2 valence electrons
main-group elements are also called
representative elements
main-group elements include groups
1,2, 13-18
main group elements…
lose or gain electrons in the outer energy level
alkali metals
group 1, has 1 valence electron, loses 1 valence electron so they have a 1+ charge
most reactive metals
alkali metals because it takes less energy to lose one electron
alkaline metals
group 1, has 2 valence electrons, loses 2 valence electrons to have a 2+ charge
alkaline metals are less
alkaline metals are less reactive than alkali metals because it takes more energy to lose 2 electrons
halogens
group 17 or VIIA, has 7 valence electrons, gains 1 valence electron so they have a 1- charge
halogens react with ___ to form ___
alkali metals to form salts
most reactive non metals
halogens are because it takes less energy to gain 1 electron
nobles gases
group 18, all noble gases except helium have 2 valence electrons, low reactivity because outer energy level is full
hydrogen
reacts with many elements because it has 1 valence electron
hydrogen is sometimes placed
is group 1 or 17 because it loses and gains 1 electron, sometimes placed at top center
hydrogen is…
flammable
transition metals
groups 3-12, form colorful compounds
transition metals are…
less reactive than groups IA and IIA because they are multivalent
what does it mean that inner transition metals are multivalent
they can lose 1,2, or 3 electrons to have charges of 1+, 2+ or 3+
inner transition metals also called
rare earth elements
inner transition metals are
the two rows at the bottom of periodic table to keep narrow
lanthanides
first row of inner transition metals, named after lanthanum
actinides
second row of inner transition metals, named after actinium
actinides are
radioactive because their nucleus is unstable
synthetic element
man-made element
what are the synthetic elements
93-118
the staircase
B, Si, As, Te, Ge, Sb
metalloids
elements that border the staircase, have properties of metals and nonmetals
what are the metals
on the left side of the staircase, including the inner transition metals, most elements
characteristic of metals
- most are solids except Hg
- conductors
- ductile
- malleable
- have luster
metals form…
positive ions by losing electrons
metals react with
nonmetals
where are non metals `
on the right side of the staircase, including hydrogen
characteristics of nonmetals
- solids, liquids and gases
- insulators
- not ductile
- brittle
- dull
nonmetals form
negative ions by gaining electrons
nonmetals react with
metals OR nonmetals
what are diatomic elements
elements that exist as 2 atoms in nature
can be written with subscript 2 like 02
name the diatomic elements
H, N, O, F, Cl, Br, I
energy level
abbreviated n, also called shell, found in the electron cloud
n=1 is also called
shell K
n=2 is also called
shell L
n=3 is also called
shell M
n=4 is also called
shell N
sublevel
found in an energy level, holds orbitals
orbital
found in a sublevel and can hold a max of 2 electrons
sublevels
s,p,d,f
s sublevel
1 orbital, 2 electrons, groups 1,2 and He
p sublevel
3 orbitals, 6 electrons, groups 13-18
d sublevel
5 orbitals, 10 electrons, groups 3-12
f sublevel
7 orbitals, 14 electrons, lanthanides and actinides
aufbau principle
electrons fill orbitals from low energy to high energy
pauli exclusion principle
no more than 2 electrons in an orbital, electrons have opposite spin
Hund’s Rule
unpaired electrons have parallel spins
electron configuration
shows distribution of electrons within sublevels
periodic trend
pattern based on the location of an element on the periodic table
shielding
when inner electron block protons from pulling electrons close to the nucleus
radius
the size of an atom or ion measured from half the nucleus to the outermost electron
atomic radius
increases from right to left
increases down
why does atomic radius increase from right to left
because nuclear charge decreases so protons cannot pull electrons close to the nucleus
why does atomic radius increase down
because energy levels are added so inner electrons shield protons from pulling electrons close to the nucleus
ionic radius
increases from right to left
increases down
why does ionic radius increase from right to left
because nuclear charge decreases so protons cannot pull electrons close to the nucleus
why does ionic radius increase down
because energy levels are added so inner electrons shield protons from pulling electrons close to the nucleus
a cation is ___ than its parent atom
smaller
why is a cation smaller than its parent atom
because a cation loses electrons so there are more protons to pull electrons close to the nucleus
an anion is ___ than its parent atom
larger because an anion gains electrons so there a not enough protons to pull electrons close to the nucleus
electronegativity defnition
ability of an atom to gain an electron
most electronegative element
F
electronegativity
increases from left to right
increases up
why does electronegativity increase from left to right
because nuclear charge increase so protons pull electrons close to the nucleus
why does electronegativity increase up
because energy levels decrease so there are not enough inner electrons to shield protons from pulling electrons close to the nucleus
ionization energy definition
energy needed to remove an electron
ionization energy
increases from left to right
increases up
why does ionization energy increase from left to right
because nuclear charge increases so protons pull electrons close to the nucleus making it harder to remove an electron
why does ionization energy increase up
because energy levels decrease so there are not enough inner electrons to shield protons from pulling electrons close to the nucleus making it harder to remove an electron
metal reactivity means
metals lose electrons
metal reactivity
increases from right to left
increases down
why does metal reactivity increase from right to left
because nuclear charge decreases so protons can not pull electron close to the nucleus making it easier to lose an electron
why does metal reactivity increase down
because energy levels are added so electrons shield protons from pulling electrons close to the nucleus making it easier to remove an electron
nonmetal reactivity means
nonmetals gain electrons
nonmetal reactivity
increases from left to right
increases up
why does nonmetal reactivity increase from left to right
nuclear charge increases so protons pull electrons close to the nucleus
why does nonmetal reactivity increase up
because energy levels are decrease so there are not enough inner electrons to shield protons from pulling electrons close to the nucleus
