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.
Regarding a recent article from phys.org , Chilean researchers have conducted a study of an old, metal-rich cluster, NGC 5927.
Interesting results are the abundance of many metals, which include sodium, aluminium, iron, oxygen and some heavy metals such as yttrium and zirconium.
Thank you.
Hi, I'm a high school chemistry teacher trying to develop a lab experience demonstrating combustion analysis. This is usually something we go through theoretically during discussion of percent composition and empirical formula. I'd like to actually perform one.
I was wondering if this could...
I need good books covering the chemistry in the college period. (Not sure if this is the correct name. Just take it to be the period after which one goes to the university.)
Any suggestions?
In physics we have this book https://www.amazon.com/dp/0321973615/?tag=pfamazon01-20
which covers...
My interest are in robotics/mechatronics, but I've been wondering if a chemistry minor would be useful for a mechanical engineer in other fields in industry.
Homework Statement
:
2 Questions, sorry about this if It adds confusion.
1) How do I go about drawing Lewis Structure Diagrams? I've searched the web, but all I can find, even when they say it's a "Lewis structure" diagram is lewis dot diagrams. My teacher wants it in the specific form where...
Homework Statement
What product(s) does this reaction produce: Acetone + diethylamine
Homework EquationsThe Attempt at a Solution
That is what I got, but the answer is N,N-dimethylethanamide. Can someone please explain why?
Homework Statement
What is the product of this reaction: p-methylbenzyn + 1,3-butadien?
Homework Equations
C6H4CH3 + C4H6
The Attempt at a Solution
a bicyclic ring is formed?
Homework Statement Homework EquationsThe Attempt at a Solution
U is internal energy, but what is u? if its internal energy at a specific state, then why its multiplied by mass? does not makes sense to me...
since specific heat c changes with temperature, but its treated as a constant in the heat formula, so that means that heat formula Q=mc(T2-T1) is just an approximation? correct?
I see some texts define heat as Heat, q, is thermal energy transferred from a hotter system to a cooler system that...
Hello,
PF in general and specifically the Intro Physics homework forum have been so helpful to me.
I have a friend who is taking (introductory?) chemistry in his first year of college, and I'm wanting to recommend one of the forums on here for him to ask questions/get help with the concepts and...
Homework Statement
Predict how many electrons will most likely be gained or lost by each element:
In this case, Gallium
Homework Equations
None (that I know of)
The Attempt at a Solution
[/B]
I know that Gallium is a metal, and metals tend to lose electrons to become cations, so I will...
Homework Statement
Here's the pic of the problem and my work
The Attempt at a Solution
I'm not sure how I'm suppose to calculate the energy change? Did i do it correctly in the picture?
For number 9, I just added IE1 and IE2 and subtracted EA1 to get a total of 3200.3. This means that the...
Cheers everyone. Can the amount of water molecules added to a solution impact the formation of a salt with its ions mainly bonded through hydrogen bonds with electrostatic like behaviour?
Let me give Some background to the question first:
I am studying the precipitation of Phosphorous(P) as...
I was curious about the chemistry of radioisotopes. Specifically, when they form coordination compounds. What happens when they decay? I know a bit about tracer molecules, but what happens to the compound after it decays? Say a coordination compound containing a radioisotope as its center atom...
What happens to an atoms chemistry as the atomic number increases.
In the case Berkelium, the electric charge from the nucleus is so powerful that the electrons must travel at relativistic speeds - becoming more massive in the process and leading to "new chemistry"...
Hello everyone! I'm currently a student about to get my AA degree at the end of the semester so the time has come for me to transfer from community college to university and, most importantly, decide on a major. Throughout my college career thus far, I've bounced around with ideas like...
The 2017 Nobel Prize in Chemistry is being announced tomorrow!
I really can't wait to see what it will be awarded for, because it is always interesting and sometimes unexpected.
I think it might be awarded for works on nanotechnology, because it is currently a hot field.
It might be displayed...
Homework Statement
I'm having difficulties figuring out how many significant figures to report for several caluclations in my lab report. As it is a report, there are no specific problem statements.
Homework Equations
No equations, but there is a rule I was told: when dividing/multiplying I...
Hello,
I have heard that the 2017 Nobel Prize in Chemistry is going to be announced in the next few months. Do you know about any interesting and/or useful discoveries that chemistry achieved worth the Nobel Prize in your opinion?
Thanks.
Hello everyone
I am doing some research about carbonic acid in fizzy drinks. I hope to find out how much carbonic acid was in the drink by looking how much CO2 bubbles come loose. but later I thought that there are two reactions that can take place:
H2CO3 --> H2O + CO2
H2CO3 --> H+ + HCO3-...
I am in a chemistry class, and there was an in class example on how to do this type of problem, but then when I looked in the book, there wasn't an equation. the questions are related to what the wavelength will be when electrons are moving between orbitals.
i am confused with charge and valency of some formula.
for carbon dioxide CO oxygen has a charge of -2 and carbon has a charge of +2. I thought though carbon is in 4 so its charge should be +/- 4.for nitrogen monoxide NO oxygen has a charge of 2- usually and nitrogen usually has a charge...
"for his studies of chemical processes on solid surfaces"
i thought nobel prize was rewarded for the research which have some meaning to the chemistry. In this study i found it hard to find some meaning.
what i found one was that some other techniques were developed because of doing this...
1. Question Statement and details : 500 mL of 56V H2O2 is kept in an open container due to which some H2O2 is decomposed and evolves 8gm O2 simultaneously, during the process some H2O also vapourizes.Due to all these changes final volume is reduced by 20%. Find final volume strength of H2O2...
Q : sample 0.2795 g containing only C6H6Cl6 (Mw = 209.8) and C14H9Cl5 (Mw = 354.5)
precipitate AgCl 0.7161 g (Calculate %(C6H6Cl6) and %(C14H9Cl5) in sample)
AgCl has 143.3 g/mol and 4.997 x 10-3
I get
0.2795 g = weight of (C6H6Cl6) + weight of (C14H9Cl5)
mol of AgCl =...
I'm a student in Pre-med looking to begin self-studying chemistry at a meticulous level. Since I've only recently graduated I haven't been too full on my course load, and I'm ready to change that immediately. However, as a student, I have no clue how I might choose great authors who give a...
Can you immerse an electrolyte in an external electric field such that the ions are separated to a point that you could introduce electrodes and produce current in a load solely by virtue of the established charge distribution without electrode chemical interaction or galvanic potential as shown...
Really struggling with this!
Here is the data:
Concentration of NaOH: .104M
Mass of Aspirin #1: .367g
Mass of Aspirin #2: .365g
Volume of NaOH mixed with Tablet 1: 50ml
Volume of NaOH mixed with Tablet 2: 50 ml
Trial 1
Mass of Na2CO3: .065g
Initial volume of HCl: 18.80mL
Final Volume...
The topic in the prize is about GPCR and from what i have researched, the research is about biology. I want to know why it was rewarded to the field in chemistry.
I bought this book "Idiot's Guide to Quantum Physics" I bought it because I know I am an idiot in quantum physics. Now I have a question about the contents. It says that:
"The four fundamental forces in nature (gravity, electromagnetism, plus two more that we'll formally introduce in Chapter...
I recently built my first distallation apparatus and in the process bought a few 105 bend take off adapter, however the angle isn't quite right and i cannot seem to source a 24/40 bent adapter/connector of any other angle! Is it just ebay/aliexpress or is 105 standard or something?
I am...
Homework Statement
What is the net heat flow of an aluminum disk (emissivity = 0.05) with radius
10 cm and temperature 293K placed inside a room where the temperature is 300K?
Asurface = π*r2 = 0.01π m2
Homework Equations
Hnet = A*e*σ(Tradiate4-Tabsorb4)
The Attempt at a Solution
By simply...
Doubts regarding the law of reciprocal proportions: What i have understood by reading the definition is that the ratio of the masses in which two elements A and B combine with a fixed mass of a third element C, will be a whole number multiple of the ratio of the masses in which A and B combine...
I'm looking for tested and proven technology for the high school chemistry class, can anyone suggest anything?
It's a passion of mine to improve labs, and teaching lessons. Lately there has been a lot of emphasis on technology in the classroom. How do you implement any technology when there are...
Homework Statement
for number 3,4,5 I'm still tryingHomework Equations
PV/T = PV/T
q = ΔU + W
W = P ΔV
The Attempt at a Solution
(3) I used PV/T = PV/T to find the ΔT for each process
for A→B I find PV/TA = P3V/TB ----- TB = 3TA (T increase)
for B→C I find P3V/TB = 4P3V/TC ----- TC =...
During the summer semester, which is around 6-8 weeks. Chemistry 1 was a breeze for me, I scored an A. I've always liked physics in high school, but I've never done physics in over a year.
Physics 1 holds 5 credits, and chemistry 2 holds 4 credits.
I'm a biology major if that changes anything.
I'm looking for a way to determine the velocity a projectile can reach from expanding gasses (explosion or deflagration). I'm sure there are a lot of variables in here, but for reference, we can work with the 12 pounder Napoleonic cannon. The powder burning is 2.5 pounds of black powder made up...
Hey!
I have a question regarding this question that I have to answer. It is about the kinetics of a substance X whose product is 2Y. It is in Swedish and here is the translation:
The absorbance of a 0,030M-solution of X was calculated with the help of a Spectrometer. The Spectrometer was...
For example: If I isolated (in a perfect vacuum), one Magnesium atom and one Oxygen atom, and they are close to each other, will they make a bond by themselves, with no outside energy? Does this work with any combinable pair of atoms, and what other pairs of atoms would make a bond by...
Hi, I am trying to simulate in 3D a bunch of chemical reactions. Some of them are complex and I would like to be able to just spawn the elements and molecules and watch them collide to see what happens. Is their any free software to do this?
Homework Statement :[/B]
The density of a 2.05 molar solution of acetic acid is 1.02g/ml. The Molality of the solution is:
(a) 1.14 mole/kg
(b) 3.28 mole/kg
(c) 2.28 mole/g
(d) 0.44 mole/kg
Homework Equations :[/B]
The Attempt at a Solution :[/B]
I tried it out very simply using unitary...
Homework Statement
http://i.imgur.com/rNoD3Lm.png
Homework Equations
Conservation of energy in an enthalpy cycle
The Attempt at a Solution
I can't complete draw the enthalpy cycle!
http://upload.lsforum.net/users/public/l50630IMG_4306s76.jpg
Can anyone help me? Thank you very much!
Homework Statement
https://holland.pk/uptow/i4/1ca04ddf7c25f6c63e307720c34a4ff3.png
Homework Equations
First principle of thermodynamics: E=q+w
The Attempt at a Solution
E=q+w=-17+21=4kJ>0
∴Endothermic (absorb heat from surrounding)
(a) false (from surrounding to the system)
(b) false (does...
Hello all,
So I've finished my first year of classes. Since my school has a credit window for declaring engineering majors, I need to lock in my life-long career decision. I definitely want to stick with engineering, but I was curious if ChemE is the right one for me. From what I've read, the...
I think this is a chemistry question...
Due to the Montreal Protocol (https://en.wikipedia.org/wiki/Montreal_Protocol) and subsequent phase-out schedule for all the “conventional” refrigerants, many/most of us in the HVAC service industry are consequently working with “interim” alternatives for...