foundations in chemistry Flashcards
define relative atomic mass
the average mass of an element compared to 1/12 mass of a carbon-12 atom
define relative isotopic mass
the mass of an atom of an isotope of an element compared to 1/12 mass of carbon-12
what is the relative atomic mass calculated from ?
masses of isotopes and abundance of isotopes
what does m/z equal ?
mass : charge ration
name the ion
a) OH-
b) Cl-
c) NO3-
a) hydroxide
b) chloride
c) nitrate
what charge does a hydroxide (OH -) anion have ?
-1
what charge does a bromide (Br -) anion have ?
-1
what charge does a chloride (Cl -) anion have ?
-1
what charge does a oxide (O 2-) anion have ?
-2
what charge does a nitrate (NO3 -) anion have ?
-1
what charge does a carbonate (CO3 2-) anion have ?
-2
what charge does a sulphate (SO4 2-) anion have ?
-2
what charge does a phosphate (PO4 3-) anion have ?
-3
what charge does a hydrogen (H +) cation have ?
+1
what charge does a sodium (Na +) cation have ?
+1
what charge does a potassium (K +) cation have ?
+1
what charge does a ammonia (NH4 +) cation have ?
+1
what charge does a calcium (Ca 2+) cation have ?
+2
what charge does a magnesium (Mg 2+) cation have ?
+2
what charge does an aluminium (Al 3+) cation have ?
+3
what charge does a silver (Ag +) cation have ?
+1
what charge does a barium (Ba 2+) cation have ?
+2
what charge does a copper [II] (Cu 2+) cation have ?
+2
write the formula of sodium chloride
NaCl
write the formula of magnesium chloride
MgCl2
write the formula of calcium carbonate
CaCO3
write the formula of ammonium carbonate
(NH4)2CO3
what is a mole ?
an amount of a substance - a certain amount of particles
it is equivalent to the number of atoms in 12g of Carbon-12
what is avogadros constant ?
6.02 x 10^23
what equation links particles, number of moles and avogadros constant ?
Number of particles = Avogadro constant x the amount of substance in mol
how much does a mole weigh ?
a mole of a substance in grams is the same as its molecular (atomic) mass
what equation links mass, Mr and moles ?
Mass = Mr x moles
what is empirical formula ?
the simplest whole number ratio of atoms in a compound
what is the empirical formula of glucose ?
CH2O
what is the empirical formula of C6H4O2?
C3H2O
how can empirical formula be calculated ?
it can be calculated from knowing the ratios in moles of the elements in a compound
which electrons are lost when an ion is formed ?
the highest energy electrons
which sub shells are exceptions to the standard rule ?
3d and 4s
4s fills before 3d but also empties before
what is the electron configuration of Cr (24 electrons)
1s2 2s2 2p6 3s2 3p6 4s1 3d5
what is the electron configuration of Cu (29 electrons)
1s2 2s2 2p6 3s2 3p6 4s1 3d10
how do you find the location of an element ?
the last number in the electron config. is the period
the letter is the block
the number of electrons is the distance along the period
what do ionic bonds exist in ?
a giant ionic lattice
do smaller ions have stronger or weaker bonding ?
stronger
what impacts attraction between ions ?
the charge density
should charge density be higher or lower to increase attraction
higher
what are the properties of giant ionic lattices ?
brittle
high melting points
conducts electricity when molten or in solution
what is the relative mass of a proton ?
1
what is the relative mass of an electron ?
1/2000
what is the relative mass of a neutron ?
1
number of protons =
number of electrons
number of neutrons =
mass number - proton number
number of electrons =
number of protons
what determines the type of atom ?
the number of protons
what are isotopes ?
atoms with the same number of protons but different numbers of neutrons
how are electrons arranged ?
in electron shells made from SUB SHELLS
what sub shells are in shell 1 ?
s
what sub shells are in shell 2 ?
s
p
what sub shells are in shell 3 ?
s
p
d
what sub shells are in shell 4 ?
s
p
d
f
what does each sub-level consist of ?
electron orbitals
what are electron orbitals ?
regions of space in which the electrons are most likely to spend their time
