lesson 3-4 Flashcards
what are the vertical columns in the periodic table?
represents groups. they are numbered from 1-18. they have the same number of valance electrons.
why is there similarities in elements in a group?
because they have the same number of valance (outer shell) electrons.
what are the horizontal rows in the periodic table?
represent a period. which are a group of electrons that have the same number of shells.
what are the physical properties of metals?
luster, good conductors of heat and electricity, high density, high melting point, ductile, and malleable.
what are the chemical properties of metal?
easily loses electrons, corrode easily.
physical properties of non-metals?
no luster, poor conductor, brittle, not ductile, not malleable, low density, low melting point.
chemical properties of non-metals?
gain electrons easily.
which group is in S block?
group 1 and group 2
which group is in p block?
group 13-18
which group is in d block?
group 3 to 12
which group is in f block?
lanthanides and actinides.
what do atomic properties depend on?
the strength of attraction between outer shell and nucleus.
what affects the attraction between outer shell and nucleus?
the positive charge that attracts the outer shell.
the distance between electrons and the nucleus.
what is the core charge and how does it behave down the group and across a period?
it’s the attraction between outer shell electron feels towards the nucleus.
group -> constant
period -> increases
what is the core charge and how does it behave down the group and across a period?
it’s the attraction between outer shell electron feels towards the nucleus.
group -> constant
period -> increases
how does the radius of the atom behave in period and a group? explain
group -> increases.
because of the increase in the number of outer shells.
period-> decreases
because the core charge increases while the number of shells stays the same.
the difference in atomic and ionic radius?
anions are larger than the original atom, while cations are smaller.
what is ionization energy?
the energy to detach one from the natural atom in a gaseous state.
how does ionization energy change down the group and across the period? explain.
group -> decrease
because size increases which means that the attraction between the outer shell and nucleus is lower.
period -> increase
because the core charge increases and the attraction between the outer shell and nucleus are greater.
how is ionization energy found?
electron impact and photo electron spectroscopy. which eject the electrons.
what is an effective nuclear charge?
the magnitude of positive charge that an electron experiences.
why does shielding occur and what is shielding?
it’s electrons partially shielding other electrons from positive charge of the core.
because of the attractions between the negative electrons and positive core and repulsion of electrons from other electrons.
how does the effective nuclear change across a period and down a group? explain.
period -> increases.
because core electrons don’t change but nuclear charge changes.
group -> doesn’t change.
what is electron affinity? and what does it mean if it has a positive electron affinity?
the amount of energy released when a neutral atom gains an electron.
means that it has a lower energy that is better than neutral atom.
what is electronegativity and what kinds are there?
measure of power when in chemical combination to attract an electron to itself.
symmetrical, asymmetrical.
what is bond dissociation energy?
the energy required to separate bonded atoms.
what is bond enthalpy?
change in heat when a bond is broken.
what is the method that allred and rocher used to measure electronegativity?
the electrostatic force exerted by a nuclear charge on valance electrons.
how does moving across a period and down a group affect electronegativity?
period -> increases
group -> decreases
what is a dipole moment?
a molecule that has a side with a negative charge core and a side with a positive charge core.
how does a dipole molecule behave in a electrical field?
the molecule will line up its negative side to the positive pole and its positive side to the negative pole.
polar molecules that don’t have a dipole moment?
a linear molecule with two identical bonds.
a planar molecule with three identical bonds.
a tetrahedral molecule with four identical bonds.
