Відео

I'm so glad this was helpful!

The neon lights use excitation of neon atoms to then emit light as the electrons relax to a lower energy level

@@ChemistrywithDrG u means excitation of electrons?

Good observation @gp1216. Considering that the electron is within the atom and the electron being excited (higher E) is synonymous with the atom being excited (higher E), we can consider it through the lens of the atom or electron within the atom being excited.

Great question. We can consider properties such as density and the type of bonding in the substance.

great question! We are going to address this question when we discuss thermodynamics. The double walled structure of the cup prevents heat from getting through the cup as it is evacuated in the middle. No gas between = no heat transfer. Similar to how some double paned windows work.

These are some great questions. For allergies, this tends to be the area most directly exposed to the allergen, which is usually ingested or inhaled. Too few or too many eggs leads to an imbalance in the egg protein binder to the rest of the ingredients for dough.

Glad it was helpful!

No we don’t. Thanks for asking though!

We gotta have fun in chemistry some times too!

This seems like that you would want to reconsider your blank that you used for the calibration of the instrument. Also, the arsenic concentration might be too low and below the LOD

The concentration might be too low and below the LOD. Also, you would want to check the blank you use for calibration as they may contribute to the negative signal.

You're welcome!! Glad it was helpful.

I am glad it was helpful. Thanks for the positive comment. What other concepts would you like to see explained or discussed?

Catalysts can be used to make materials with less waste and faster. They also reduce the amount of energy needed to make industrial products, such as biodegradable plastics.

Awesome question. Depending on the sunscreen, in can be titanium (IV) oxide suspended in the sunscreen or an organic molecule like oxybenzone. These substances absorb energy in the UV range, preventing the UV light from hitting your skin.

This has a lot to do with the pathways in the body that are blocked, that prevent inflammation or pain from translating from a part of the body to the brain.

Amazing question. I think this article from NIH gives a great explanation - www.ncbi.nlm.nih.gov/books/NBK223808/#:~:text=Caffeine%20increases%20intracellular%20concentrations%20of,free%20fatty%20acids%20and%20glycerol.

Many times it has to do with how our body responds, through antibodies, etc. to a chemical or substance in the allergen.

One of the major components of vapor rubs is menthol. This article from NIH gives a good overview of how menthol reacts to our airways. www.ncbi.nlm.nih.gov/pmc/articles/PMC3628651/

In a way, these extracts come from natural products and get extracted many times via steam distillation. The steam is passed over leaves (such as Eucalyptus), which "dissolves" the oil from the leaves, then they are cooled and the water vapor separates from the oil since they have different boiling point temperatures (and vapor pressures at the same temperature)

When they are first produced, they are air dried (or freeze dried) to remove the water content, which helps the noodles last longer. Then we just add hot water, which quickly cooks the partially cooked noodles and you have a quick meal. :)

Amazing question! This is because the highlighters actually contain molecules that fluoresce! They absorb the light energy from the visible spectrum, then they emit their own light at a different wavelength, which in a way they "glow." This added fluorescent emission causes the highlighters to be even brigher than normal pigments. Normal pigments simply reflect light at a specific wavelength, which is why they are not as bright.

Such a great question, and this article by NIH gives a better answer than I ever could. pubmed.ncbi.nlm.nih.gov/23545161/

great question, they are not able to transfer heat as well. They have a high capacity to prevent molecular KE transfer (heat) and do not promote the movement of KE through their materials.

Such a fantastic question Natalie. The primary mechanism that causes hair damage from exposure to pool chlorine is that the sodium hypochlorite (pool chlorine) can dissolve and remove your hair oils, which makes your hair more susceptible to air and sun damage.

Great observation! It is not necessarily that the water in the bottles expire, but there is a slow leaching of substances from the plastic of the bottle into the water and at a certain point, the concentration of leached materials gets too high to be considered safe and the water "expires."

Amazing question. I think this article from NIH gives a great explanation - www.ncbi.nlm.nih.gov/books/NBK223808/#:~:text=Caffeine%20increases%20intracellular%20concentrations%20of,free%20fatty%20acids%20and%20glycerol.

fantastic question Isabella. This has a lot to do with the affected structure of some proteins, but this article from NIH gives a good overview of this - www.nia.nih.gov/health/alzheimers-causes-and-risk-factors/what-happens-brain-alzheimers-disease#:~:text=In%20Alzheimer's%20disease%2C%20however%2C%20abnormal,the%20synaptic%20communication%20between%20neurons.

This has a lot to do with the pathways in the body that are blocked, that prevent inflammation or pain from translating from a part of the body to the brain.

Plastics usually start from natural gas or oil and through a few chemical reactions. Usually, the smaller molecules, like ethane and propane, are dehydrogenated to form ethylene or propylene. These are then polymerized (connected together in long chains of many ethylene or propylene molecules bonded together), which forms the plastics. That is why plastic bottles can be labeled as polyethylene or polypropylene.

many times, tooth decay occurs from bacteria, when the bacteria creates acidic compounds that are released onto the teeth, which causes the teeth to dissolve. Think of how vinegar (weak acid acetic acid) can dissolve an egg shell, but much slower in our mouth on our teeth.

This can be influenced by many things. The size of the molecule that we smell with the perfume, the air movement (wind, air purifiers), and the diffusion of other molecules. Great question. Many times, the larger the molecule that we smell from the perfume, the faster it will deposit out from the vapor or gas phase as gravity pulls it back to the surface.

Fantastic question. We will think about this when we focus on intermolecular forces, molecular shapes, and interactions

This is such a timely question! We are actually going to use those in class on the first day!

Amazing question. We will consider interaction of molecules based on structure during class and hope you get to think in depth about the interaction of molecules then!

Thank you very much. I appreciate the feedback.

You will be using a comparison. You will have a standard solution that has a known amount of the analyte you are interested in quantifying (for example caffeine) and a known internal standard concentration added (for example benzoic acid) and get a signal for both caffeine (analyte) and benzoic acid (internal standard). Then you will add the same amount of benzoic acid to your unknown solution as an internal standard. Get the signal for both caffeine and benzoic acid, then compare the signals for caffeine and benzoic acid from the standard solution to the unknown solution.

Glad it was helpful

Glad it was helpful!

You could think about measuring an external standard with a known concentration with the instrument. Then dope in the same standard analyte amount into the sample and see if you get the same signal increase in the doped standard as in the external standard. For example, an external standard with a concentration of 0.2 M gave a signal of 0.5. The sample gives a signal of 0.3 for the analyte. If the sample doped with 0.2 M gives a signal of 0.8 (the sum of the sample and the external sample signal) then there is no matrix effect. However if it differs from this then you know there is a matrix effect.

Glad it was helpful!

Great question. If you are unaware of the concentration of your sample, you will want to do some research about the instrument you are using. What is the linear range possible with the instrument? What is the LOD or LOQ? Then, do a first test of your sample with a dilution, to make sure that the pure sample will not overload your detector or your analytical system. If it is low, then analyze the sample at higher and higher concentrations, until you get a significant signal.

@@ChemistrywithDrG thank you for replying 🙂 so helpful !

@@za7607 Glad it was helpful!

Glad it was helpful! Thank you for letting me know.

thank you for letting me know. I made sure to change the way this was done for future videos.

I appreciate the connection you see between chemistry and physics. In chemistry, we tend to focus on the connection of enthalpy to chemical reactions.

Glad it was helpful

thanks for sharing! I will post the answer on Sunday.

great thoughts, but what about the gun powder reaction does this?

@@ChemistrywithDrG maybe there is a chemical that is highly reactive to the fire when it is heated a reaction happens

Yes. I think so too Kevin!

Glad to hear it is helpful.

Great. Glad you liked it.

Glad to see you liked it Vincent. More of these types of videos are in production.