CHEMISTRY COMMUNITY

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it's just a general knowledge and is always true.
double bond is longer than triple bond but shorter than single bond.

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as long as the pi bond exist, the double bond(which contains pi bond and connects two atoms) can't not rotate, so they must be in the same plane.

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as long as they show a symmetrical geometry, and all bonds connect to the same element. it's non-polar

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cis molecule has same types of atoms on the same side.
trans molecule has same types of atoms on the opposite sides.
So, even the polar bonds exists, but the trans molecule is non-polar in general since they oppositely arranged atoms' dipole moments cancel out.

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Coordination compound is where Ligands（ lone pairs donar，lewis base）attached to a Transition Metal ion that forms coordinative bonds between them. Ligands can be differnet kinds, as long as they have long pairs of electrons to donate. They can be anions like Cl-,Br-,F-, they can also be neutral e.g....

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they have to use lone pairs to form coordinative bondS with the TM ion.

Monodentate ligand is a lewis base that donates one lone pair of electrons to a TM ion to form a bond.
Biodentate ligand is a lewis base that donates 2 lone paris of electrons to a TM ion to form 2 bond.

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NH3 has 4 regions of electron density, 3 of them are bonding pairs and 1 of them are lone-pairs. AX3E1 Although it is arrangded tetrahedrally, but the way to minimize the repulsion betweena atoms rearrange the atoms to form a TRIGONAL PYRAMIDAL shape Why we call it pyramidal? since it looks like a p...

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Water molecule has a BENT SHAPE Although it has 4 regions of electronic density, which mean it is arranges tetrahedrally But 2 of the regions are because of lone pairs, while 2 others are bonding pairs So it causes a larger repulsion than the tetrahedral(109.5), also larger than the trigonal pyramid...

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no matter what type of bond is occurring, you just consider it as a single bond, which means yes, one double bound is still AX
That's why we said in VSEPR model, the resonance does not matter.

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no, there is no difference.
As professor mentioned, all of them 3 describe the same thing, but the induced dipole-induced dipole is the best one that demenstrartes what's actually going on.

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actually the trend of electronegativity and first ionization energy is the same but just keep In mind there are several exceptions
for example, the first ionization energy of N is actually larger than O

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it means all atoms with same number of electrons
for exmaple Na has 19 electrons but Mg has 20 electrons, so they are not isoelectronic
but Na and Mg- are isoeletronic since Mg- has 20 electrons as well

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all the elements in the 5th and 6th column (N,O,S,P...) share the same trend exceptions, which means N>O, P>S. because of the half-filled p-orbital is stable All elemetnts in the 4th and 5th column(Mg,Al..) share the same trend excpetion, which means Mg>Al, becuas of full-filled of p-orbital is stable

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ground state means a normal performance of an atom, which means the atom itself is not excited by external force. Just think about water for example, under normal conditions, it's "ground state" is liquid. But if you increase the temperature to boil it, it get "excited" and turns...

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copper and chromium are the only 2 exceptions that disobeys the regular rules you need to remember for this course.
For copper and chromium, the 3d orbital is half-filled or fully-filled since they wanna get more stable.

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Any moving mass will have a wavelike property with wavelength of λ, this equation is DeBroglie Equation which is λ=h/mv
however light does not have a mass so, it's not feasible to light(photons)

The more massive of a subject, it's visible wavelength is lower. So it will become undetectable.

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light is the fastest speed in the whole universe
according to the General Relativity. If there is something faster than light...then the whole theories of physic will collapse!
so if the value of speed you calculated is faster than 3E8, it's unrealistic

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just remember P=mv where m is a constant which is the mass of a electron, 9.11E-31 kg And according to Heisenberg Indeterminacy (Uncertainty) Equation: px=h/4pi, and because p=mv, so mvx=h/4pi put in all the variable, where m=9.11E-31, x=350pm=350E-12 m, h=6.63E-34, we get the final answer 165469.22...

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The ionic radius is between ionic compound, such as NaCl, KCl. Atomic radius is between neighbouring atoms, for example metal Mg, Fe By the way, covalent radius measn 2 nonmetal joined by the covalent bond, eg, oxygen, Nitrogen Howeverever, dont care much about it because all radiuses follow the sam...

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Are you talking about the first ionization energy? if it is, then the first ionization energy increases across the period and decreases down the group Reasons for that is because of 1. proton numbers which determine the nuclear attraction 2. number of shells which determined by the number of electro...

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Typically larger the atomic number(more protons), the more massive the atom will be. Because the atom is composed of electrons, which basically have no or little mass, and proton & neutrons. The mass of atom is focus on the nucleus, in other words, the nucleus( proton & neutron) determines t...

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light is descried as a wave because it has interference, diffraction. Details seen Thomas Young Experiment
Light is described as a particle because of photoelectric effect, which demonstrates that the intensity does not affect the amount of electrons get out, but wavelength/frequency does.

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The first thing you need to know is that all electromagnetic radiation, including light, follows the equation C=frequency x wavelength, where C is the constant, that is the speed of light.(Proper estimated value 3E8) So, whatever it happens, C is never changing. Always be equal to 3E8 Acoording to t...

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in reality, the light's speed is less than 3E8. But 2.998E8 is much more complicated to calculation and maybe difficult to evaluate. Considered about above, we use 3E8 in calculation since there is not much difference. So, yes , 2.998E is actually more accurate, but not convenient for massive calcul...

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we need material in which the electrons are mobilized--means they have free moving electrons.
Therefore, any materail that has free-moving electrons are good for this experiment. But the metal is one of these cases

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pretty easy
always remember this equation： known molar mass/molar mass from empirical formula

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mol is a unit, that saying 6.02E23 molecules is inside. So when I say one mole of atoms(molecules), it means there are 6.02E23 atoms(molecules). Atomic mass is the property of an element, as you can see on the periodic table, each element has specific atomic mass. For example, for O is 16 and H is 1...

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if in the question the number is 0.500g for example， then all your calculation must be in 3 significant figures.

CHEMISTRY COMMUNITY

Search found 28 matches

Re: Bond Length

Re: Atoms in a Plane

Re: Chapter 4 [ENDORSED]

Re: cis and trans

Re: Coordination compound

Re: Ligands

Re: Ammonia shape [ENDORSED]

Re: shape of water

Re: VSEPR

Re: London Dispersion, Induced dipole- Induced dipole, Van Der Waals

Re: Relationship between Electronegativity and Ionization Energy

Re: Isoelectronic [ENDORSED]

Re: Ionization exceptions [ENDORSED]

Re: What does ground state mean? [ENDORSED]

Re: electron configuration of chromium? [ENDORSED]

Re: When to use DeBroglie or Ek equation

Re: In class problem [ENDORSED]

Re: HW #1.43

Re: Radius

Re: ionization energy

Re: atomic mass

Re: Wave vs. Particle

Re: frequency and wavelength [ENDORSED]

Re: Speed of Light which is more accurate? [ENDORSED]

Re: Photoelectric Effect on different material? [ENDORSED]

Re: Formula steps

Re: Units + their meanings

Re: Sig figures