Periodic Law Flashcards
original periodic table was created by?
Dimitri Mendeleev
An element’s period number(row) is the same as the number of energy levels that the electrons of its Atoms occupy. True or false
true
all elements in each main group have the same number of valence electrons. True or false
true
atomic radius increases as you go left and down. why?
valence electrons occupy energy levels further from the Nucleus
inner electrons shield the valence electrons from the attraction of the Nucleus
1st ionization energy is
the energy required to remove an electron from an atom.
elements react to end up with the same number of electrons as the nearest noble gas. what is this called
isoelectronic
what is electron affinity
it is a measure of the change in energy that occurs when an electron is added to the outer energy level of an atom to form an negative ion.
decrease down a group
increase across a period
VSEPR
applies only to ____
Covalent
tetrahedral
# of bonding e pairs
# of lone e pairs
bond angles example
4
0
109.5
CH4
trigonal pyramidal # of bonding e pairs # of lone e pairs bond angles example
3
1
107.3
NH3
bent (angular) # of bonding e pairs # of lone e pairs bond angles ex
2
2
104.5
H2O
trigonal planar # of bonding e pairs # of lone e pairs bond angles ex
4
0
120
CH2O
linear # of bonding e pairs # of lone e pairs bond angles ex
varies
varies
18p
CO2. H2. N2
two or more elements and or small compounds react to form a larger compound
A +B -> C
synthesis
compound breaks down into elements and or other compounds
C -> A + B
decomposition
scientific name for burning.
reaction of an element or compound with oxygen to form the most common oxides of the elements that make up the compound
combustion
what are the products of combustuon
carbon dioxide and water
element in a compound is replaced by another element. what is this called. what are the two types
single displacement
metal replaces metal or hydrogen
non metal replaces non metal
involves the exchange of positive ions (cations ) in aqueous solution (water)
AB + CD -> AD + CB
double displacement
metals react with oxygen to form __
metal oxides. always SOLID
metal oxides react in water to form ____
bases. basic oxidases
non metals react with oxygen to form _____
non metal oxides. usually liquid or gas
non metal oxides react in water to form ___
acids
or acidic oxides
Heating hydrates causes it to decompose into an “____” ___ and ____
anhydrous salt and water vapour
a carbonate when heated will decompose into ?
MgCO3
metal oxides and carbon dioxide gas
decomposition of nitrates typically result in ?
ex. KNO3
nitrogen gas, oxygen gas, and a metal oxide
N2 + O2 + K2O
decomposition of bicarbonate results in ?
NaHCO3
carbonate + water vapour + carbon dioxide
Na2CO3 + H2O + CO2
