atomic structure Flashcards
what is it and where does metallic bonding occur?
-in metallic elements and alloys
-no transferring or sharing of electrons
-atoms have weak attraction
-everything is attracted
metallic bonding structure
-can only form lattices (positive ions surrounded by delocalized electrons)
-atoms have weak attraction so they from delocalized electrons
metallic bonding properties
high mpt/bpt: strong electrostatic forces(more delocalized e-s the higer the mpt/bpt)
malleable, cations can move around without breaking the electrostatic forces
can conduct because delocalized e-s can move around(not as a gas)
insoluble in all solvents (can react)
identifying bonding and structure
-conductivity as a solid:
yes, metallic or graphite
no, ionic, covalent
-solubility in water:
yes, ionic(exceptions)
no, covalent(exceptions), metallic
-solubility in oils:
yes, covalent(discrete)(exceptions)
no, ionic, covalent (lattice)
-MPT:
yes, covalent discrete
no, ionic, covalent lattice, metallic
-conductivity liquid:
yes, ionic, metallic
no, covalent
-conductivity aquose:
yes, ionic
no, covalent, metallic, ionics that are insoluble
how do ionic substances have specific properties?
by the type of particles and forces present
when does ionic bonding occur
between oppositely charged ions
what is ionic bonding
when a compound contains at least one metal and one non-metal
bonding
describes the way that particles “join” together
structure
describes the 3D arrangement of particles as a result if bonding
covalent bonding
occurs between atoms of 2 non-metals.
the non-metals can be the same (element) or they can be different (compound)
the atoms share a electron
what is an atom
smallest unit of matter that retains its properties
what are subatomic particles
the 3 fundamental particles that constitute atoms:
proton, neutron, electron
particles and their relative mass and charge
proton: 1, +1
neutron: 1,0
electron: 1/1836, -1
atomic number
number of protons, definition of an element, the periodic table is listed in order of number of protons.
atoms are…
neutral, therefore number of protons = number of electrons
mass number
number of protons + no of neutrons
neutrons
mass number - atomic number
relative mass of 1
relative charge of 0
isotopes
-atoms of the same element with different numbers of neutrons
-they have identical chemical properties, they have similar but different physical properties
element
a substance made of atoms with the same number of protons
pure
only an element present (same protons)
isotopically pure
only one isotope (same protons, same neutrons)
ion
charged atom or molecule
cation= positive
anion= negative
when do particles become charged
when protons =/ electrons
why can electrons be easily gained or lost
-the electrons are located on the outside of the atom(less energy required to remove)
-the electrons are much smaller than the protons
ionic bond
electrostatic force of attraction between oppositely charged ions
what is a lattice
a 3D repeating pattern
structure of ionic bonding
lattice of alternating cations and anions that are held together with electrostatic forces
mpt/bpt of ionic bonding
high melting point becuase of the electrostatic forces that are very strong and each ion has multiple attractive forces, therefore lots of energy is needed to weaken the forces.
what does the strength of each force depend on in ionic bonding
magnitude of charge and the radius of each ion (the charge is more dispersed of bigger ions)
conductivity in ionic bonding
charged particles are present (ions) but cannot conduct as a solid because they can’t move. as a liquid of dissolved they can move so they can conduct charge.
solubility in ionic bonding
dissolves in water
maluability in ionic bonding
brittle, movement of ions in the lattice causes to repel
why does covalent bonding share an electron
because both atoms attract the shared electron equally and therefore the atoms join (molecule)
covalent bond
electrostatic attraction of 2 nuclei for a shared pair of electrons
what are the forces in covalent discrete
-strong covalent bonds that hold the molecule together. these only change during reactions
-weak IMFs holding groups of molecules together. these are affected by physical processes (melting dissolving)
properties for covalent discrete
-low mpt/bpt; the weak IMFs require little energy to weaken. the mpt depends on the size of the molecules. (bigger more IMFs=higher mpt)
-do not conduct as they don’t have any charged particles
-soluble in oil like substances and low solubility in water. when they dissolve the molecules separate from each other breaking the IMFs.
what are the 3 substances that have lattice covalent
SiO2: sand
C: diamond, or graphite
description of covalent lattice
lattice of atoms held together with strong covalent bonds( no weak IMFs)
properties of covalent lattice
-very high mpt because strong covalent bonds needing lots of energy to break
-does not conduct because no charged particles are present
-insoluble in all solvents
-brittle because the atoms can only move if the covalent bonds break, the bond cannot reform in the new position.
what is diamond and graphite
both are different allotropes of carbon
allotrope
different structural arrangements of the same element. same chemical properties but different physical properties.
diamond properties
high mpt (covalent lattice)
doesn’t conduct
insoluble in all solvents
brittle
graphite properties
-high mpt (same as diamond)
-conduct electricity as a solid because of delocalized electrons
-insoluble
-lubricant: layers of atoms can slide over each other without disrupting the rest of the lattice.
graphite and diamond structure
graphite: lattice of atoms arranged in alternating layers w/ delocalized electrons (covalent lattice)
diamond: triangle based pyramid (covalent lattice)
protons
relative mass of 1
relative charge of 1
electrons
relative mass of 1/2000
relative charge of -1
calculating average mass of isotope (Ar)
abundance x mass the same
________________ +
100
particles becomes charged when…
the number of protons =/ no. of electrons
covalent structures have 2 types of bonding
strong covalent bonds in the molecule
weak IMFs holding molecules together
atomis mass
combined mass of protons and neutrons
the more neutrons in isotopes
the greater mass = greater density
higher mpt –> can be seperated by fractional distallation
