What is Chemistry: Definition and 993 Discussions

Chemistry is the scientific study of the properties and behavior of matter. It is a natural science that covers the elements that make up matter to the compounds composed of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during a reaction with other substances.In the scope of its subject, chemistry occupies an intermediate position between physics and biology. It is sometimes called the central science because it provides a foundation for understanding both basic and applied scientific disciplines at a fundamental level. For example, chemistry explains aspects of plant chemistry (botany), the formation of igneous rocks (geology), how atmospheric ozone is formed and how environmental pollutants are degraded (ecology), the properties of the soil on the moon (cosmochemistry), how medications work (pharmacology), and how to collect DNA evidence at a crime scene (forensics).
Chemistry addresses topics such as how atoms and molecules interact via chemical bonds to form new chemical compounds. There are two types of chemical bonds: 1. primary chemical bonds e.g covalent bonds, in which atoms share one or more electron(s); ionic bonds, in which an atom donates one or more electrons to another atom to produce ions (cations and anions); metallic bonds and 2. secondary chemical bonds e.g. hydrogen bonds; Van der Waals force bonds, ion-ion interaction, ion-dipole interaction etc.

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  1. S

    Chemistry Is this the right way to approach solubility problem?

    Is my work and the answer correct? If not, how should I approach this problem? Thank you!
  2. Rzbs

    Lithium-ion rechargeable batteries

    I want to know how a lithium ion rechargeable cell works with very basics details. I don't need a simple describtion like most of the websites and videos. I need a resource that explain the chemistry and physics of a Li ion cell from very basics of knowledge. Could you please introduce such a...
  3. P

    Who is Nwanaga Chikamso Placid and What Drives Their Passion for Research?

    My name is Nwanaga Chikamso Placid. Am a Nigerian. I love research and have interest to know and learn all the time. Hope am welcome.?
  4. R

    Exploring Nucleus Speed: How Fast Do Elements Spin in Their Designated Space?

    I am looking for information on multiple things but, currently, looking for how fast each element's nucleus spins/moves in its "designated space". Does the nucleus itself rotate? If so, how fast? And is it different for different element's? (I'm not sure I'm doing this correctly. I just need to...
  5. ambivalent_chemicist

    Programs Major in Chemistry or Physics?

    As with probably a lot of pure science undergrads, my dream goal is to become a researcher, academia or industry. As far as I know at the moment, I'm interested in the area of research that straddles physics and chemistry, and I'm not sure which one I should major in. Should I major in chemistry...
  6. A

    Programs Need advice about choosing Physics or Chemistry for my Master's degree

    Hi , I 'd like to make a master degree but am not sure which department should I join to meet my goals that I will tell you about shortly , let's begin by my background first, Background : I have a bachelor in computer and communications engineering , during my study I had basic Electronics...
  7. il postino

    Chemistry Chemistry equilibrium - Remove H2

    It is desired to remove the molecular hydrogen present in a flask. What will be better to introduce, ##Cl_2## or ##Br_2##? Why? ##2 HCl <-> H_2 + Cl_2## (1) ##k = 3,2.10^{-14}## ##H_2 + Br_2 <->2 HBr## (2) ##k = 2.10^9## I thought about turning equation (1) to make the...
  8. Amitkumarr

    Chemistry Coordination chemistry problem

    My attempt- 1)The given ligand forms chelate rings,so it should be a chelating complex. 2)It has no plane of symmetry (P.O.S),so it is optically active(octahedral complex) and should have 2 optically active isomers. 3)They are not polymerisation isomers because they have different emperical...
  9. E

    Chemistry Equivalent of Irodov for Chemistry?

    I need to brush up on some Chemistry over Summer, and I wondered if anyone knew of some problem books pitched at a similar level to Irodov's problem book for Physics, or things like IChO questions. Preferably it would include all of physical, inorganic and organic, to some degree. I get various...
  10. S

    Trying to Understand Ionization

    It will try to produce a neutral atom but it depends on the amount of energy that electron is shot at the atom, if it is great enough energy for ionization it will produce cation, If it is not enough for ionization it will make a neutral atom or anion, I think.
  11. S

    Chemistry Electron Affinity: Adding Electrons to Valance Shells

    I think that an electron adds up in the valance shell of an atom because an atom tends to achieve the nearest noble gas configuration. But I don't understand how and why electron enters the valance shell. Energy is released when an electron adds up in the valance shell. But why is energy...
  12. C

    Chemistry of Bitumin Road Degeneration

    All our bitumin roads decay over time by ultraviolet light and slightly acid water. What is the chemistry of this? There is a lot of stuff on the internet about change in physical degeneration but not chemical degeneration? What is a suitable reference?
  13. shintashi

    B Is there a Relativistic Quantum Chemistry Table?

    Wiki said "Arnold Sommerfeld calculated that, for a 1s orbital electron of a hydrogen atom with an orbiting radius of 0.0529 nm, α ≈ 1/137. That is to say, the fine-structure constant shows the electron traveling at nearly 1/137 the speed of light.[9] One can extend this to a larger element with...
  14. .Scott

    I Is Chemistry the same everywhere?

    A new article in Phys.org discusses a paper recently published in "Science Advances". Although I am unable to find that article. Professor Webb at USNW reports that there appears to be a gradient across the universe over which fine structure constant varies. (Wow!)
  15. Terrakron

    Teaching Chemistry labs and demonstrations online now -- Suggestions Please

    Summary:: How to do chemistry labs and demonstrations for online education. I am teaching two lab sessions one on general chemistry, one on organic chemistry. Now th we are going “online” I need a lot of help. Do you have videos showing labs?
  16. cwill53

    Programs Double Major in Electrical Engineering and Physics?

    I’m a freshman in undergrad and I currently attend the University of Illinois at Chicago. I major in electrical engineering but I have an extremely strong interest in physics, chemistry, and materials science. UIC doesn’t have a materials science program, but George Crabtree, a highly cited...
  17. Ifrah tahir

    Please help me solve this % numerical chemistry problem

    I've tried both c1v1 and unitary method but couldn't solve
  18. C

    Perfect Espresso Water Chemistry

    Hey all, I've come here to seek out some help creating the perfect espresso brewing water. I've done some research, and I think I've reduced it down to a chemistry problem. I'll be starting with distilled water and adding minerals, some 'hardness' and an 'alkalinity buffer.'First, here's the...
  19. H

    Is [A-] greater than [H3O+] in a 1M solution of highly acidic HA?

    The question says: A solution of highly acidic HA is given, with a molarity of 1M. Is it true that [A-]>[H3O+] or not? I simply don't understand why the hydronium is mentioned and i don't know how to find the molarity of these two individually.
  20. Suppaman

    When does chemistry become life?

    Summary: At some point, there has to be a point where the "goo' (as described by "Q") becomes us, what is that transition point? What made not life, life? <moved to general discussion> I have been looking around the internet for an answer to this question. The difference between "life" and "not...
  21. fbeaker

    Spectrophotometric Determination of Fe2+ (Beer's Law)

    I am having troubles with a question I have to do for my chem pre-lab. The question is: The following intercept and slope were obtained for a Beer’s Law plot of Absorbance versus concentration (mg Fe2+/L). Slope = 0.2200 L/mg Fe2+ Intercept = 0.004 Calculate the percent (by mass) of iron in the...
  22. DrClaude

    What groundbreaking work led to the 2019 Nobel Prize in Chemistry?

    https://www.nobelprize.org/prizes/chemistry/2019/summary/
  23. M

    Chemistry Ideal Gas Problem | Get Help Now!

    Hello guys. I really try to understand the problem, can you please help.
  24. Navin

    Chemistry Compare the Bond lengths of IO2F2 and IOF3

    Okay So our Chemistry Professor gave us the answer as the following IO2F2 has a larger bond length than IOF3 The reason being is once you draw the structures of the compounds IO2F2 has more number of double bonds that the later hence it shall have more p charecter than IOF3...hence it will...
  25. cookiemnstr510510

    Most acidic proton: first semester organic chemistry

    Hello All, I have attached my questions with pictures in attached photos. Look at screen shot 46 first then screen shot 47. I am having trouble ranking acidic protons. In my Organic book it has the order of: 1)Charge 2)Atom Type 3)Hybridization 4)Resonance 5)Induction Things I know: S is able...
  26. J

    Chemistry undergrad attempting to go to graduate school in physics

    Summary: Chemistry undergrad attempting to go to graduate school in physics. Would appreciate advice. Hello, I am in my fourth of five years at a solid school studying chemistry. I changed my major at the start of my third year from economics to chemistry after being inspired by a course in...
  27. Amblambert

    Chemistry Quantum Chemistry - Particle in a box

    Here is my attempt at a solution. The thing I am not sure about is the final result of the Shrodinger equation and the n-values that are offered? Did I make a math mistake? Thank you so much for reading through this!
  28. S

    Chemistry Need help with this threshold limit value (TLV) chemistry problem

    I'm getting 2119.36 for the concentration of mg/cubic meter of this substance...it just feels wrong though. Steps I followed: First, I figured out how many grams of the substance there were using the density formula, then saw how many were present per cubic meter after calculating the volume...
  29. O

    I Efficiency of computers vs. brains

    Hi, I’m an undergraduate student interested in cognitive processes. I’m about to ask a very interdisciplinary question, and so hopefully I can find a physicists that can take on the challenge. What is the fundamental reason behind why modern electronic computers (transistor computers) are...
  30. M

    Chemistry What is the ratio of pH=Pka-1?

    I think it is 1:10 but I am not sure the meaning of PKa -1, can someone explain it please.
  31. TonyKonya

    Specific Heat at High Temperatures

    I am working on some simulations to determine pressures for extremely high-pressure combustion events. The temperatures in these events can range anywhere from 3000 K to 6000 K. In order to do this I need to find valuers for specific heats of gases at these temp ranges as I know they vary to a...
  32. Jamister

    Quantum Where Can I Find Rigorous Books on Physical Chemistry for Master's Level Study?

    I'm master physics student looking for books in physical chemistry for stuff like born Oppenheimer Approximation and more. Most books give hand-waving proofs and I'm looking for a book which is more rigorous. Thanks
  33. P

    Calculating Emission Wavelength for Excited Atoms at 3.031x10^-19 J Energy Level

    Problem Statement: A sample of excited atoms lies 3.031×10^−19 J above the ground state. What is the emission wavelength of these atoms? Relevant Equations: E=hc/λ λ=hc/E I'm stuck on the first part. i.e; something / 3.031x10^-19J
  34. bagasme

    Courses Introductory Chemistry Requirement for Physics Majors: Why is it Mandatory?

    Hello, I looked into lists of subjects/courses for Physics Major, and I surprised that Introductory Chemistry is in the list, as mandatory course. I suspect that Molecule and Solids and Nuclear Physics chapter have to do with chemistry Why is it mandatory to take Introductory Chemistry course...
  35. Fabrizio Vassallo

    What is the composition of the Earth's exosphere?

    Hello! My name is Fabrizio, I'm a high school student doing some research on the atmosphere. Right now, I'm trying to figure out how much matter escapes into space via Jean's Escape. I've found several formulas, all of which require me to know what the amount of particles per m3 of a certain...
  36. trienebutdiene

    2020 US National Chemistry Olympiad

    Summary: Thread for discussing the USNCO and how to do well on it. More specifically, tips for doing well on the national round and making the study camp are welcome. Anyone with experience with the olympiad is welcome to post, especially previous study camp qualifiers and honors/high honors...
  37. K

    Decomposition reaction for theophylline, hexobarbital natrium

    Hello! There is a problem to write chemical reactions that goes with substances if they are not stored properly. For example theophylline should be saved from light and though I am trying to find its’ reaction with hv(light) but failed. Please help with some good reference Many thanks in advance
  38. KristinaMr

    What Happens to Bromines in a Double Bond in Organic Chemistry?

    I think that the double bond would be broken in some way but what happens to the two bromines? do they remain in the ring? (or does HBr forms? is it possible?)
  39. nineteen

    How to get the balanced redox equation in this sample problem?

    Summary: Our chemistry teacher gave a sample problem regarding balancing a redox equation. I managed to proceed to a considerable distance, but I can't seem to understand how to get the final balanced equation. Please help me out. The problem is; reaction of K2Cr2O7 with SO2 in the presence of...
  40. N

    Do chemists think differently than physicists?

    Summary: Do chemists think differently than physicists? And should I Change my subject in University... Hey guys, I'm asking myself this question in hoping to find myself in life… some advice and ideas would be really helpful. I'm from Europe and I'm actually studying chemistry. I still Need...
  41. pinball1970

    I Helium Hydride data, Early universe chemistry evidence?

    I don't think there is a thread on this? R Gusten et al, Nature, 2019, DOI: 10.1038/s41586-019-1090-x
  42. E

    Entalphy of Formation: Why Use Water at Std Cond?

    why do we use the entalphy of formation of water at standard conditions to calculate the entalphy of a reaction even if water is not gas at 1bar and 298K
  43. avishay

    How to convert pressure (Bar) to flow rate (L/min)?

    hii, I'm try to calculate the pressure (in bar) needed for a certain flow rate 3 L/min of Argon gas given the following setup: - I have a tank of Argon gas and the line pressure can be between 0 bar to 5 bar. - The gas will flow out to the open air in the end. - My pipe has an internal radius...
  44. A

    Atomic High School Chemistry Textbook Recommendation

    Can someone please tell me what high school chemistry textbook that studying about octet rule is best for an idiot like me?
  45. M

    Chemistry Molar solubility lab questions

    I’m confused on how to calculate molar solubility because I don’t see what’s the difference between that and Ksp.
  46. DrTherapist

    Programs Can I Use My Chemistry Background for Research in Physics?

    I did not opt for physics for my degree course (BSc), I am sort of regretting it. Now, I'd rather want to get close to physics as much as possible. I like physical chemistry, I was thinking I should change my area of interest from neuroscience to physics cause honestly physics is much more...
  47. C

    Does temperature increase when water is boiling at 100C......

    Does temperature increase when water is boiling at 100C in a closed system? I am picturing a scenario where I am boiling water in a pot to make pasta. However, I decide to close the pot as the water is still boiling. By doing this I am sealing away the system of study from the environment. Thus...
  48. K

    Why is DeltaG Negative for H2O(l) to H2O(g) at Equilibrium?

    Calculate deltaG for the reaction: H2O(l) = H2O(g). 100 degrees celsius, water is clean. P(H2O) = 0.1 bar. Given that it is an equilibrium, I'd think that deltaG would be zero. But the answer is in fact negative. How is that possible?
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