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Metals always form _______.
Cations
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Non-metals always form _______.
Anions
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Cations are _______ than their neutral counterparts.
Smaller
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Anions are _______ than their neutral counterparts.
Larger
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Metals
Very large atoms with loosely held electrons...Form cations, are lustrous, ductile, malleable, and excellent conductors of both heat and electricity...they are usually only involved in ionic bonds.
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Non-metals
Smaller atoms with loosely held electrons...Form anions, have much lower melting points than metals, and with very few exceptions, only nonmetals form covalent bonds.
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Large atom characteristics
Larger atoms are better at stabilizing charges, form weaker pi bonds, and have d orbitals where they can "stash" extra electrons.
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Alkali metals
Group 1, 1 electron in outer level, very reactive, soft, silver, shiny, low density; Lithium, Sodium, Potassium, Rubidium, Cesium, Francium
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Alkaline earth metals
Metallic elements in group 2 of the periodic table which are harder than the alkali metals and are also less reactive.
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Lanthanides
The first of the two rows below the main part of periodic table. usually used in alloys, soft, malleable, shiny and good electrical conductors.
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Actinides
In the 2nd row of transition metals, radioactive, unstable, do not occur in nature.
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Electron Affinity
- The amount of energy released when an electron is added to a neutral atom or molecule to form a negative ion.
- X + eā ā Xā
It increases from left to right and from bottom to top
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Electronegativity
The ability of an atom to attract electrons when the atom is in a compound.
It increases from left to right and from bottom to top
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Ionization Energy
The energy required to remove 1 mole of electrons from 1 mole of gaseous atoms or ions. Large atoms or molecules have a low ionization energy, while small molecules tend to have higher ionization energies.
It increases from left to right and from bottom to top
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Atomic Radius Trends
Atomic radius gets larger from right to left and top to bottom.
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Metallic Character Trends
Increases from right to left and top to bottom
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Metallic characteristics
BIG and low low ionization energy
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First Quantum Number
"n" (the principle quantum number)
Gives the shell (i.e. Valence electrons are in the outermost "shell") and is approximately equal to the relative energy of electrons in that shell.
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Second Quantum Number
" " (the azimuthal quantum number)
- Gives the subshell: has values of 0,1,2,3 and from this were know the shape:
- 0=S ; 1=P ; 2=d ; 3=f
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Third Quantum Number
"m " (the magnetic quantum number)"the magnetic quantum number"
Gives the orbital; has a value of - to (from the azimuthal quantum number)
The orbital is the portion of the subshell where an electron is most likely to be found (i.e., which "dumbbell" of a p subshell)
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Fourth Quantum Number
"ms" (the electron spin quantum number)
Gives the spin which is either +1/2 or -1/2 (Positive is up arrow or negative is down arrow)
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Heisenberg uncertainty principle
States a fundamental limit on the accuracy with which certain pairs of physical properties of a particle, such as position and momentum, can be simultaneously known.
The more precisely one property is measured, the less precisely the other can be controlled, determined, or known. You can know it's momentum, or where it's at, but you can't know both at the same time.
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Pauli exclusion principle
No two electrons in a single atom can have the same four quantum numbers; if n, , and m are the same, ms must be different such that the electrons have opposite spins, and so on.
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The Work Function
If you bombard certain metals with energy, you can cause the ejection of an electron from their outermost shell (i.e. valence electron). The amount of energy required to do this is called the "work function."
This is not the same as the Ionization energy because that refers to only lone atoms in a gaseous state. The work function refers to the valence electrons being ejected from the surface of a metal.
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Work Function formula
KE = E –
- - work function variable
- KE - of the ejected electron
- E - amount of energy added
-or-
E = hf
- E - energy of a photon
- h - Planck's constant
- f - frequency
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Alpha Decay
A He nucleus (2 neutrons and 2 protons) are ejected
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Beta Decay
Neutron is changed into a proton (with the ejection of an electron)
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Electron Capture
A proton is changed into a neutron via capture of an electrion
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Positron Emission (beta+ decay)
A proton is changed into a neutron (with expulsion of a positron)
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Calculating Percent Mass
Mass of one element divided by the total mass.
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Deriving a formula from percent mass
- 1. Change the percent for each species into grams by assuming 100g. (i.e. 17% = 17g)
- 2. Convert the grams of each species into moles by dividing by molar mass.
- 3. Look at the element with the lowest number of moles. Calculate approximately how many times it will divide into each of the other molar amounts for each of the other elements--this number is the subscript for each element in the empirical formula. If the subscripts are not at their lowest common denominator, reduce to get the empirical formula.
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How to determine moles from mL
m = V * P
mass (g) = volume (cm3 or mL) * density (g/cm3)
Then divide mass by molecular weight to get moles.
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What is a coordination compound?
When one atom donates both electrons to a covalent bond with another atom with a + charge.
Complex usually has a metal center.
Most common example is NH3
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What characteristic determines how polar a hydride will be?
Electronegativity
The more electronegative, the stronger the polarity.
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