Chemistry Unit 6 Flashcards
Coulomb’s Law
When attraction goes up, then magnitude goes up and distance^2 goes down.
What is atomic radii?
Distance from the center of the nucleus to the boundary of the e- cloud.
Atomic radii group trend?
Larger, new energy levels of electrons. d^2 goes up, so attraction goes down. More e- shielding effect also weakening attraction of p+/ve- and increasing distance.
Atomic radii period trend?
Smaller, stronger positive to negative attraction from an increase in p+/ve-. Magnitude goes up, so attraction goes up (d^2 goes down).
Shielding Effect
The inner (core) electrons cause an interference and block the nucleus (p+) from the outer ve-. The more e-=more shielding effect.
What is first ionization energy?
The energy required to remove the most loosely held electron.
Ionization energy group trend?
Decreases, added energy level weakens attraction between p=/ve-. More Shielding effect. Easier to remove ve-. Coulombs: d^2 goes up, so attraction goes down.
Ionization energy period trend?
Increases, attraction between p+/ve- is greater, more protons(nuclear charge). Harder to remove e-. Coulombs: mag goes up, attraction goes up
Electronegativity
Attraction an atom has for a bonding pair of electrons (attract e- towards itself).
Electronegativity group trend?
Decreases, less attraction due to e- being further from nucleus. More shielding effect (bigger size). Coulombs: d^2 goes up, so attract goes down
Electronegativity period trend?
Increases, added p+/e- so greater attraction for e- (smaller size). Coulombs: magnitude goes up, attraction goes up.
What is reactivity?
How completely and easily an atom bonds to another (lose/gain/share).
Reactivity METALS group trend?
Increases, larger it is easier to lose e- due to distance and shielding effect.
Reactivity METALS period trend?
Decreases, smaller so hold on to e- is stronger due to more p+ and ve-.
Coulombs: magnitude goes up, attraction goes up.
Reactivity NONMETALS group trend?
Decreases, larger so less attraction to (others) ve-. Coulombs: magnitude goes up, attraction goes up.
Reactivity NONMETALS period trend?
Increases, smaller so more attraction to ve- and others. Coulombs: magnitude goes up, attract goes up.
Ionic size as compared to atom; which ANIONS and what is their trend?
(-), gained e- (not p+). NONMETALS larger because gained e-, e- repel other e- and expand. More (-) = larger anion. Cl is smaller and Cl^- is larger.
Ionic size as compared to atom; which CATIONS and what is their trend?
(+), lost e- (not p+), METALS smaller because lost electrons. Nucleus can pull e- in closer. more (+) = smaller cation. Fe is larger than Fe^+3.
If we make all the atoms ions:
Same trend as atomic radii but it starts over at the staircase.
are you ready for the test??
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What ions do METALS form?
Cations (+)
What ions do NONMETALS form?
Anions (-)
What is the periodic law?
When arranged by increasing atomic number, there are chemical and physical properties that repeat periodically.
What is a period?
Horizontal
What is a group?
Vertical
What are representative elements?
Elements in groups 1A-8A
What did Dobereiner contribute?
“triad”- three elements with similar properties. Ex: Li, Na, K
What did Newlands contribute?
Law of Octaves- Every 8th element, properties repeat. NOT octect rule: atoms gain or lose electrons to obtain 8 valence electrons.
What did Meyer contribute?
Arrangement by atomic mass. Chemical properties repeat every so many elements.
What did Mendeleev contribute?
Arrangement by INCREASING atomic mass. Predicted unknown elements by leaving spaces in the table. Germanium, Gallium, Scandium
What did Moseley contribute?
Arrangement by increasing atomic number.
Properties of METALS
small number of ve-, easily lose ve-, cations, good electrical and heat conductors, ductile, malleable, lustrous, solid at room temp
Properties of NONMETALS
several ve-, anions, poor conductors of heat and electricity, non-ductile, brittle, not luster, s-l-g at room temp
Properties of METALLOIDS
Both metal and nonmetal properties
Properties of Alkali metals
soft, very reactive, stored under oil so they don’t react
Properties of Alkaline earth metals
a little less soft, more mildly reactive, only react at temps when water is steam
Properties of Halogens
Very smelly (ew!), burn flesh, does not dissolve well in water, reacts with most metals and many nonmetals
Properties of noble gases
Not very reactive, do not like forming compounds with other elements, very stable
Lanthanides
rare earth metals, similar across period, all solid
Actinides
radioactive, similar across period, all solid
Transition metals
contains everyday metals
Malleable
bent or shaped easily
Ductile
can be stretched into wire
Atomic radius
Distance from the middle of the nucleus to the boundary of the electron cloud.
