Search found 95 matches

by Martina
Sun Feb 23, 2020 11:29 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Difference
Replies: 5
Views: 26

Re: Difference

This delta G is based off of knowing the delta H and delta S.
by Martina
Sun Feb 23, 2020 11:26 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: State
Replies: 5
Views: 10

Re: State

It is usually given in the problem or the equation unless it is something obvious like oxygen gas.
by Martina
Sun Feb 23, 2020 11:24 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagrams
Replies: 4
Views: 17

Re: Cell Diagrams

Platinum can be used to transfer electrons if there is no other conducting solid.
by Martina
Sun Feb 23, 2020 11:21 pm
Forum: Balancing Redox Reactions
Topic: Potential Difference
Replies: 5
Views: 22

Re: Potential Difference

Potential difference is the energy in volts needed to change an electrical charge.
by Martina
Sun Feb 23, 2020 11:17 pm
Forum: Balancing Redox Reactions
Topic: Test 2 Topics
Replies: 7
Views: 29

Re: Test 2 Topics

Test 2 includes the end of outline 4 and all of outline 5 (Electrochemistry) which I think will be covered during week 8.
by Martina
Sun Feb 23, 2020 11:15 pm
Forum: Balancing Redox Reactions
Topic: Reduced/Oxidized
Replies: 5
Views: 26

Re: Reduced/Oxidized

You would have to balance the charges of all the molecules in the equation and see which ones lose electrons making the oxidized and which ones gain electrons making them reduced.
by Martina
Sun Feb 16, 2020 11:25 pm
Forum: Balancing Redox Reactions
Topic: oxidation number
Replies: 6
Views: 17

Re: oxidation number

You have to check the known charges of the ions and make sure that they balance out for the entire equation.
by Martina
Sun Feb 16, 2020 11:24 pm
Forum: Balancing Redox Reactions
Topic: Rules for oxidation numbers
Replies: 6
Views: 13

Re: Rules for oxidation numbers

Ions have a different number of electrons and protons, so they will have a charge depending on that difference.
by Martina
Sun Feb 16, 2020 11:23 pm
Forum: Van't Hoff Equation
Topic: Van't Hoff Equation
Replies: 3
Views: 15

Re: Van't Hoff Equation

This equation can be used to calculate the equilibrium constant when the temperature and delta G are known. This helps to compare K at different temperatures.
by Martina
Sun Feb 16, 2020 11:20 pm
Forum: Van't Hoff Equation
Topic: T1 and T2
Replies: 7
Views: 28

Re: T1 and T2

This equation lets you solve for K at different temperatures, so it can show you the change in the equilibrium constant between T1 and T2.
by Martina
Sun Feb 16, 2020 11:19 pm
Forum: Van't Hoff Equation
Topic: Van't Hoff Equation
Replies: 3
Views: 13

Re: Van't Hoff Equation

This equation lets you solve for K if you have delta G and the temperature. It can also be used to calculate K at a different temperature if delta H is known by setting delta G equal to delta H minus T delta S.
by Martina
Sun Feb 16, 2020 11:15 pm
Forum: Van't Hoff Equation
Topic: Equilibrium Constant
Replies: 4
Views: 29

Re: Equilibrium Constant

If delta G is zero then that means the reaction is at equilibrium. So Q must be equal to the equilibrium constant K.
by Martina
Sun Feb 16, 2020 11:10 pm
Forum: Balancing Redox Reactions
Topic: Why do we split equations?
Replies: 12
Views: 31

Re: Why do we split equations?

It makes it easier to understand which atoms are losing electrons and which are gaining electrons in the reaction.
by Martina
Sun Feb 09, 2020 11:31 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Sudden vs. Gradual
Replies: 3
Views: 15

Re: Sudden vs. Gradual

Sudden expansion represents irreversible reactions while a gradual expansion represents a reversible expansion because of the small gradual expansion that allows for the most work to happen.
by Martina
Sun Feb 09, 2020 11:26 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Heat capacity
Replies: 6
Views: 22

Re: Heat capacity

Monoatomic particles have a heat capacity of 3/2 R. For liner molecules it is 5/2 R because there are more possible positions for the molecule.
by Martina
Sun Feb 09, 2020 11:24 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Entropy Surroundings
Replies: 4
Views: 40

Re: Entropy Surroundings

The change in temperature would be when there is no heat or pressure.
by Martina
Sun Feb 09, 2020 11:21 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Standard reaction enthalpy
Replies: 2
Views: 8

Re: Standard reaction enthalpy

You can use either, both are correct it just depends on what is given.
by Martina
Sun Feb 09, 2020 11:19 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Difference between Cv and Cp?
Replies: 8
Views: 33

Re: Difference between Cv and Cp?

Cv is 3/2 R and is used under constant volume and Cp is 5/2 R and is used under constant pressure.
by Martina
Sun Feb 02, 2020 11:44 pm
Forum: Phase Changes & Related Calculations
Topic: Calorimeters
Replies: 8
Views: 25

Re: Calorimeters

It only matters if it is a bomb calorimeters instead of a regular calorimeter.
by Martina
Sun Feb 02, 2020 11:42 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hess's Law
Replies: 4
Views: 15

Re: Hess's Law

You have to make sure all of the products and reactants cancel out by flipping some of the equations and changing the sign. Then you can add all the enthalpies.
by Martina
Sun Feb 02, 2020 11:41 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Forming bonds
Replies: 8
Views: 26

Re: Forming bonds

Forming bonds is exothermic because it releases energy, while breaking bonds requires an input of energy so it is endothermic.
by Martina
Sun Feb 02, 2020 11:40 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: thermochemistry equations
Replies: 5
Views: 23

Re: thermochemistry equations

Most of them are on the constants sheet and are given during the test.
by Martina
Sun Feb 02, 2020 11:38 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: qp = ΔH?
Replies: 5
Views: 26

Re: qp = ΔH?

This is true when the pressure is constant.
by Martina
Sun Feb 02, 2020 11:37 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Delta H and U
Replies: 3
Views: 15

Re: Delta H and U

H stands for enthalpy and U is for internal energy.
by Martina
Sun Jan 26, 2020 11:58 pm
Forum: Phase Changes & Related Calculations
Topic: Hess's Law
Replies: 5
Views: 16

Re: Hess's Law

Enthalpy is a state function, meaning that only the beginning and endpoints matter, not the path taken or the intermediate values. For this reason enthalpy is additive.
by Martina
Sun Jan 26, 2020 11:56 pm
Forum: Phase Changes & Related Calculations
Topic: Temp. of sample
Replies: 4
Views: 12

Re: Temp. of sample

The energy is being used to change the state of matter for that period of time instead of to increase the temperature.
by Martina
Sun Jan 26, 2020 11:55 pm
Forum: Phase Changes & Related Calculations
Topic: State Function
Replies: 3
Views: 13

Re: State Function

Enthalpy is additive because only the end value matters, not the actual pathway taken, no those values can be added.
by Martina
Sun Jan 26, 2020 11:28 pm
Forum: Phase Changes & Related Calculations
Topic: Test 1
Replies: 6
Views: 28

Re: Test 1

I think we might get them back in discussions next, but it might be later.
by Martina
Sun Jan 26, 2020 11:27 pm
Forum: Phase Changes & Related Calculations
Topic: ∆H
Replies: 17
Views: 64

Re: ∆H

I think that it is, unless you know whether the reaction releases energy or requires it.
by Martina
Sun Jan 19, 2020 11:09 pm
Forum: Ideal Gases
Topic: Ideal gas law and [P]/[R]
Replies: 3
Views: 24

Re: Ideal gas law and [P]/[R]

You use it to convert between pressure and concentration since concentration is (n/V).
by Martina
Sun Jan 19, 2020 11:07 pm
Forum: Ideal Gases
Topic: Using PV=nRT
Replies: 7
Views: 35

Re: Using PV=nRT

Yes you can use it find find pressure if you have the molarity (n/V) or vice versa.
by Martina
Sun Jan 19, 2020 11:04 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: exothermic/endothermic rxns
Replies: 4
Views: 19

Re: exothermic/endothermic rxns

Exothermic reactions release energy, so energy is basically one of the products. Endothermic reactions require energy so energy is a reactant. So when you increase energy it favors the other side.
by Martina
Sun Jan 19, 2020 11:03 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: lewis structure
Replies: 11
Views: 40

Re: lewis structure

I think you needs to understand how the protons or electron pairs are transferred, but you do not actually have to draw it.
by Martina
Sun Jan 19, 2020 11:02 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: temperature
Replies: 10
Views: 40

Re: temperature

Temperature is the only thing that affects the equilibrium constant, so it changes the value of k.
by Martina
Sun Jan 19, 2020 11:01 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: pKa and pKb
Replies: 17
Views: 68

Re: pKa and pKb

These are just logarithmic versions of Ka and Kb, their relationship is that they add up to 14.
by Martina
Sun Jan 12, 2020 11:05 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Partial Pressure
Replies: 3
Views: 23

Re: Partial Pressure

I don't think you could calculate that without being given the temperature.
by Martina
Sun Jan 12, 2020 11:03 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: The concept of Gibbs Free Energy
Replies: 4
Views: 20

Re: The concept of Gibbs Free Energy

Gibbs free energy can help determine whether a reaction release or requires energy. I think this will be important later in the class but not much for this unit.
by Martina
Sun Jan 12, 2020 11:00 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: pressure and volume
Replies: 4
Views: 20

Re: pressure and volume

Pressure and volume have an inverse relationship. When a gas is condenses into a smaller space the pressure increases, and when the gas has more space the pressure decreases.
by Martina
Sun Jan 12, 2020 10:56 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Concentration
Replies: 6
Views: 31

Re: Concentration

You do use units for concentration, but not the equilibrium constant because the units of products over reactants cancel out.
by Martina
Sun Jan 12, 2020 5:22 pm
Forum: Ideal Gases
Topic: ICE tables
Replies: 4
Views: 17

Re: ICE tables

An ICE table has three rows in which you list the Initial molar concentration, Change in molar concentration, and Equilibrium molar concentration for all of the products and reactants. It can be used to determine the concentration of the equilibrium mixture.
by Martina
Sun Dec 08, 2019 12:32 am
Forum: Naming
Topic: Abbreviations
Replies: 6
Views: 53

Re: Abbreviations

I think all of these abbreviations are okay for the final.
by Martina
Sun Dec 08, 2019 12:31 am
Forum: Naming
Topic: bis- tris- tetrakis-
Replies: 8
Views: 75

Re: bis- tris- tetrakis-

You use these prefixes any time it is polydentate, so you would use it for oxalato, en, dien, and edta.
by Martina
Sun Dec 08, 2019 12:30 am
Forum: Naming
Topic: Ferrate and Cuprate? [ENDORSED]
Replies: 5
Views: 55

Re: Ferrate and Cuprate? [ENDORSED]

If the complex is negative you have to add -ate to the end of the metal. The only exception is iron and copper, which change to ferrate and cuprate.
by Martina
Sun Dec 08, 2019 12:27 am
Forum: Biological Examples
Topic: Coordination Compounds
Replies: 2
Views: 16

Re: Coordination Compounds

I think you need to memorize all of the ones given on the list in his website.
by Martina
Sun Dec 08, 2019 12:26 am
Forum: Biological Examples
Topic: Polydentate
Replies: 3
Views: 30

Re: Polydentate

Polydentate just means that it bonds at more than one site, hexadentate says the actual number of bonds it can make. Both are correct though.
by Martina
Sun Dec 08, 2019 12:25 am
Forum: Biological Examples
Topic: Hemoglobin
Replies: 4
Views: 43

Re: Hemoglobin

Four myoglobin create a hemoglobin, and each myoglobin can carry one oxygen. So total 4 can be carried by a hemoglobin.
by Martina
Sun Dec 08, 2019 12:24 am
Forum: Biological Examples
Topic: Hydrogen Bonding sites
Replies: 8
Views: 53

Re: Hydrogen Bonding sites

Any hydrogen attached to a F, O , or N , and any lone pairs on those atoms can make hydrogen bonds.
by Martina
Sun Dec 08, 2019 12:22 am
Forum: Biological Examples
Topic: Cisplatin
Replies: 5
Views: 57

Re: Cisplatin

The chlorines are on the same side and bind to DNA twice, which stops cell division.
by Martina
Sun Dec 01, 2019 7:31 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: sigma bond
Replies: 7
Views: 66

Re: sigma bond

A sigma bond is a bond between two orbitals (s and s, s and p, etc) where they overlap end to end and can rotate.
by Martina
Sun Dec 01, 2019 7:28 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Fundamentals
Replies: 5
Views: 51

Re: Fundamentals

I am not sure but I don't think we need to know bond order.
by Martina
Sun Dec 01, 2019 7:27 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Content of the final
Replies: 10
Views: 160

Re: Content of the final

I don't think molecular orbital theory or bond order will be on it.
by Martina
Sun Dec 01, 2019 7:25 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Diamagnetism and Paramagnetism
Replies: 2
Views: 28

Diamagnetism and Paramagnetism

What is the difference between diamagnetism and paramagnetism?
by Martina
Sun Dec 01, 2019 7:22 pm
Forum: Hybridization
Topic: Hybridization
Replies: 7
Views: 66

Re: Hybridization

I think that's all. You just need to memorize the hybrid orbitals.
by Martina
Sun Dec 01, 2019 7:19 pm
Forum: Hybridization
Topic: Hybridization and Orbital Shape
Replies: 2
Views: 18

Re: Hybridization and Orbital Shape

Hybridization of two orbitals changes the shape because they combine to share electrons and become a different shape.
by Martina
Sun Nov 24, 2019 5:24 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Specific Naming Question
Replies: 4
Views: 38

Re: Specific Naming Question

If it asks for the shape, then you have to say see-saw. If it asks for the electron geometry as well then it is trigonal bipyramid.
by Martina
Sun Nov 24, 2019 5:22 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent vs linear
Replies: 56
Views: 344

Re: Bent vs linear

A bent molecule has a lone pair which pushes the other atoms away from it, causing a bent shape.
by Martina
Sun Nov 24, 2019 5:20 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: sigma bond
Replies: 7
Views: 66

Re: sigma bond

A sigma bond means that the orbitals overlap end to end. Sigma bonds also allow for rotation.
by Martina
Sun Nov 24, 2019 5:18 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Dipole Moment?
Replies: 4
Views: 26

Re: Dipole Moment?

If the molecule has symmetry then the dipole moments likely will cancel out and make the overall molecule nonpolar.
by Martina
Sun Nov 24, 2019 5:16 pm
Forum: Hybridization
Topic: Single Electron Orbitals
Replies: 2
Views: 29

Re: Single Electron Orbitals

Single electrons can still form a bond.
by Martina
Sun Nov 24, 2019 5:14 pm
Forum: Hybridization
Topic: Sigma and Pi bonds
Replies: 13
Views: 65

Re: Sigma and Pi bonds

You just have to label one as a sigma bond and one a pi bond if its a double bond. If it is triple then one sigma and two pi.
by Martina
Sun Nov 17, 2019 8:18 pm
Forum: Bond Lengths & Energies
Topic: Polarizability
Replies: 4
Views: 35

Re: Polarizability

Polarizability increases with size and negative charge. So larger anions have the highest polarizability.
by Martina
Sun Nov 17, 2019 8:17 pm
Forum: Bond Lengths & Energies
Topic: Lone pairs
Replies: 7
Views: 77

Re: Lone pairs

Lone pairs are usually located in a place where they form fewer bond angles with other atoms. So in the See Saw shape they are located on the equatorial plane where they only interact with 2 bonds.
by Martina
Sun Nov 17, 2019 8:13 pm
Forum: Bond Lengths & Energies
Topic: 3F5 a
Replies: 2
Views: 27

3F5 a

Suggest, giving reasons, which substance in each of the following pairs is likely to have the higher normal melting point
(Lewis structures may help your arguments): (a) HCl or NaCl

Why is the melting point of NaCl higher that HCL?
by Martina
Sun Nov 17, 2019 8:10 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Repulsion strength and Bond Angles
Replies: 12
Views: 55

Re: Repulsion strength and Bond Angles

Yes, the lone pair repels the other bonds, causing the bond angle between them to be slightly less than what is expected.
by Martina
Sun Nov 17, 2019 8:08 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Radicals
Replies: 5
Views: 40

Re: Radicals

Yes, a radical with a single electron is still considered a domain for the electron geometry.
by Martina
Sun Nov 10, 2019 11:14 pm
Forum: Dipole Moments
Topic: Instantaneous Dipole
Replies: 2
Views: 19

Instantaneous Dipole

What is an instantaneous dipole and how do you identify it?
by Martina
Sun Nov 10, 2019 10:22 pm
Forum: Dipole Moments
Topic: Hydrogen Bonding
Replies: 6
Views: 28

Re: Hydrogen Bonding

They are the strongest intermolecular bonds but no stronger than ionic or covalent bonds.
by Martina
Sun Nov 10, 2019 10:20 pm
Forum: Dipole Moments
Topic: dipole
Replies: 4
Views: 39

Re: dipole

A molecule has a dipole moment if it has a partial negative a positive charge due to uneven sharing or electrons.
by Martina
Sun Nov 10, 2019 4:16 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polairzability characteristics
Replies: 3
Views: 27

Re: Polairzability characteristics

It is harder to break the bonds in a more polarizable atom and covert it to a liquid or gas.
by Martina
Sun Nov 10, 2019 4:14 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability
Replies: 4
Views: 30

Re: Polarizability

Polarizability increases toward Francium (like atomic radius) while polarizing power increases toward Fluorine (like elecronegativity)
by Martina
Sun Nov 03, 2019 9:50 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 3
Views: 21

Formal Charge

Do you have to calculate formal charges for every lewis structure you draw, or only if it is specified in the question.
by Martina
Sun Nov 03, 2019 9:49 pm
Forum: Resonance Structures
Topic: Showing resonance
Replies: 8
Views: 46

Re: Showing resonance

You can use the solid and dashed lines or you can draw all of the possible lewis structures and explain that the resonance is a hybrid of all of them.
by Martina
Sun Nov 03, 2019 9:46 pm
Forum: Octet Exceptions
Topic: Identifying Radicals
Replies: 6
Views: 52

Re: Identifying Radicals

I think you can usually tell it is a radical if there is an odd number of valence electrons.
by Martina
Sun Nov 03, 2019 9:43 pm
Forum: Formal Charge and Oxidation Numbers
Topic: formal charge
Replies: 4
Views: 29

Re: formal charge

Another way to think about it is FC= valence electrons - (number of lone pair electrons + number of bonds)
by Martina
Sun Nov 03, 2019 9:40 pm
Forum: Dipole Moments
Topic: Polarizability
Replies: 1
Views: 18

Polarizability

How much of polarizability do we need to know for the midterm? Thanks!
by Martina
Sun Oct 27, 2019 9:19 pm
Forum: Dipole Moments
Topic: Dipole Moments
Replies: 2
Views: 32

Dipole Moments

How do you determine if there is a dipole moment, and what exactly causes it?
by Martina
Sun Oct 27, 2019 9:17 pm
Forum: Octet Exceptions
Topic: octet exceptions
Replies: 5
Views: 35

Re: octet exceptions

It also helps to know that exceptions are in the third period because they can fill their d orbital with electrons as well.
by Martina
Sun Oct 27, 2019 9:09 pm
Forum: Resonance Structures
Topic: Octet
Replies: 13
Views: 91

Re: Octet

Atoms like P, S, and Cl also can be an exception because they can accommodate more than 8 valence electrons.
by Martina
Sun Oct 27, 2019 9:06 pm
Forum: Trends in The Periodic Table
Topic: Ionization Energy
Replies: 9
Views: 31

Re: Ionization Energy

Ionization energy is always positive because you need energy to remove the electron. Second ionization energy is higher because the charge difference between the positive nucleus and the electrons is greater, so it is even more difficult to remove another electron.
by Martina
Sat Oct 26, 2019 1:20 am
Forum: Resonance Structures
Topic: Bond Lengths
Replies: 5
Views: 260

Re: Bond Lengths

The resonance structure is a blend of the different possible lewis structures of a molecule. The bond lengths of the resonance structure will all be the same and will be somewhere between the lengths of all the possible bonds.
by Martina
Sun Oct 20, 2019 10:02 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Paired & Parallel Electrons
Replies: 4
Views: 27

Re: Paired & Parallel Electrons

Parallel electrons have the same spin and will have the same sign for the spin magnetic quantum number while paired electrons have opposite spins so one will have a negative spin magnetic QN will the other will be positive.
by Martina
Sun Oct 20, 2019 9:48 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration Rules
Replies: 3
Views: 22

Electron Configuration Rules

Why is the electron configuration for Chromium [Ar] 3d5 4s1? Can someone please explain the exceptions to electron configuration rules?
by Martina
Sun Oct 20, 2019 9:42 pm
Forum: Quantum Numbers and The H-Atom
Topic: Quantum Number
Replies: 4
Views: 35

Re: Quantum Number

Yes I think you need to know them for the s, p, d, and f orbitals.
by Martina
Sun Oct 20, 2019 9:33 pm
Forum: Quantum Numbers and The H-Atom
Topic: Spin Quantum Number
Replies: 3
Views: 36

Spin Quantum Number

What is the difference between an atom having a positive spin quantum number versus a negative one?
by Martina
Sun Oct 20, 2019 9:30 pm
Forum: Quantum Numbers and The H-Atom
Topic: Quantum Numbers
Replies: 5
Views: 27

Re: Quantum Numbers

The magnetic quantum number labels the different orbitals of a subshell. It can be any number from negative l to positive l.
by Martina
Sun Oct 13, 2019 8:30 pm
Forum: Properties of Light
Topic: 1B.25
Replies: 1
Views: 22

1B.25

Can someone explain how to do the calculations for this problem? What is the minimum uncertainty in the speed of an electron confined within a lead atom of diameter 350. pm? Model the atom as a one-dimensional box with a length equal to the diameter of the actual atom.
by Martina
Sun Oct 13, 2019 8:18 pm
Forum: Quantum Numbers and The H-Atom
Topic: Atomic Spectra
Replies: 5
Views: 46

Re: Atomic Spectra

Yes, they always correspond but the amount of energy depends on the atom.
by Martina
Sun Oct 13, 2019 8:04 pm
Forum: Properties of Electrons
Topic: Photoelectric Effect
Replies: 3
Views: 32

Photoelectric Effect

Can someone explain why the results of the photoelectric experiment so surprising or unexpected?
by Martina
Sun Oct 13, 2019 7:56 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect and Photons
Replies: 6
Views: 45

Re: Photoelectric Effect and Photons

A photons is a unit or packet of energy that interacts with exactly one electron. Each one should have enough energy to remove an electron.
by Martina
Sat Oct 12, 2019 9:07 pm
Forum: Properties of Light
Topic: 1A.3
Replies: 4
Views: 41

1A.3

Which of the following happens when the frequency of electromagnetic radiation decreases? Explain your reasoning. (a) The speed of the radiation decreases. (b) The wavelength of the radiation decreases. (c) The extent of the change in the electrical field at a given point decreases. (d) The energy o...
by Martina
Sat Oct 05, 2019 11:51 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Atoms, Molecules, and Formula Units
Replies: 4
Views: 81

Re: Atoms, Molecules, and Formula Units

Avogadro's Constant is a quantity that can be used for any item. It just the amount of those items so it can be used for atoms, molecules, or anything else.
by Martina
Sat Oct 05, 2019 11:45 pm
Forum: SI Units, Unit Conversions
Topic: Temperature
Replies: 6
Views: 63

Re: Temperature

I think he also meant that both temperatures use the same scale, so there is 100 degrees difference between freezing and boiling for both.
by Martina
Sat Oct 05, 2019 2:31 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Theoretical vs. Actual Yield
Replies: 38
Views: 523

Re: Theoretical vs. Actual Yield

Actual yield is less than theoretical yield due to experimental errors such as sticking to the sides, incomplete reactions, or loss of the sample.
by Martina
Sat Oct 05, 2019 2:18 pm
Forum: Empirical & Molecular Formulas
Topic: M 15
Replies: 1
Views: 27

M 15

Aluminum metal reacts with chlorine gas to produce aluminum chloride. In one preparation, 255 g of aluminum is placed in a container holding 535 g of chlorine gas. After reaction ceases, it is found that 300. g of aluminum chloride has been produced. I am unsure about the first part of this problem ...
by Martina
Sat Oct 05, 2019 1:28 pm
Forum: SI Units, Unit Conversions
Topic: Rounding
Replies: 6
Views: 75

Re: Rounding

I usually try to keep the number in my calculator and avoid rounding it while doing the problem so that the answer is the most accurate. When showing I just put a few decimals even though I am using the entire number in my calculator.

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