chemistry! URGENT

59,905 results, page 25

Chemistry

I need definitions for chemistry and I can't come up with any heterogeneous reaction homogeneous reaction activation energy activation energy activated complex elementary reaction

chemistry

I have a question in chemistry relating to identifying a compound that would precipitate the iron ions out of a water supply. I am unsure of a compound that would react to produce the iron as a precipitate that could be removed. Thoughts?

Chemistry

1. How could a chemistry student change NaOH(s) to NaOH(aq)? s= solid aq= aqueous 2.) How could a chemistry student change NaOH(s) to NaOH(l) s= solid l= liquid

Chemistry

Concentration 15.8 mg/L Final Volume 100.0 mL What is the concentration of phosphate in the original lake water sample if the unknown lake water sample in the option has been diluted by taking 25.0 mL of lake water and diluting it to the indicated final volume? •Chemistry - ...

Math

At Small Town High there are 100 students, each of whom takes at least one of biology, chemistry, or physics. There are 50 students in biology, 60 in chemistry, and 70 in physics. If 24 students are enrolled in exactly two of these classes, how many students are in all three?

physics (Urgent)!!!!!!!!!!!!!!!!!!!!!!

A pendulum of mass m= 0.9 kg and length l=1 m is hanging from the ceiling. The massless string of the pendulum is attached at point P. The bob of the pendulum is a uniform shell (very thin hollow sphere) of radius r=0.4 m, and the length l of the pendulum is measured from the ...

Organic Chemistry

Does anybody know of a website that explains organic nomenclature ? ...something along the lines "organic nomencluture for Dummies" would be great :-) I'm stuggling to underatand "Z-3-Bromo-6-methyloct-3-ene" let alone draw it ! Here is a site that might just be what you are ...

Chemistry

Find the value of delta H net for the following equation: SnBr2(s) + TiCl4(l) -> TiBr2(s) + SnCl4(l) I know that I already posted this once but I am still lost on what to do. I know that TiCl4=-804.2 and SnCl4=-511.3 but I thought that the values for SnBr2 is 0 as well as ...

math/ chemistry

so I have this chemistry problem which involves math and basically I need to convert 62 g/mol into mol/L but I don't know how. like do you DIVIDE the g/mol by 1000 to convert g to L? and then how to you get the mol to become the numerator?

US Gov help URGENT

I'm very ignorant when it comes to politics. I had to write a summary on Shutdown looms: Spotlight now on Senate after Boehner wrangled House GOP votes If you go to google and type that in it's the first link.. Can someone give me some key pointers as to how the info in that ...

English

Could you please check these sentences,please? It's really urgent. I made some changes and I would like to know if they are correct. 1) The interior monologue has the following features. First, it is immediate since it lacks the conventional syntax and it is free from ...

math-urgent please help

Newton’s Law of Cooling states that the temperature of a heated object decreases exponentially over time toward the temperature of the surrounding medium. The temperature u of a heated object at a given time t can be modeled by the following function: u(t)=T+(u-T)e^kt K<0...

Chemistry

For Chemistry, I have to design a coin. What are some anti-counterfeiting measures I could use to prevent people from replicating it? I've googled this, but I haven't found many good ideas. I can only think of putting grooves on the edge of the coin and, and making it of an ...

organic chemistry

a careless organic chemistry student was performing "competing nucleophiles in nucleophilic substitution reactions" experiment , and left his container of tert-butyl chloride and tert-butyl bromide open to the air for several hours. what happened to the composition of the ...

chemistry

I'm working on substitution organic chemistry problems and I just had a question. There's an equation in which a molecule is treated with methanol in an acetone solution. Would the reaction be SN1 or SN2? I thought that it was SN2 because of the aprotic acetone, but the answer...

help needed !!! URGENT

Can some one help me I don’t know what to take out from the aspirin molecule, for the following structures? I have to generate a copy of the molecular structure of aspirin and then for each of the molecular features listed in (i) – (iii) have to produce a related structure...

Chemistry

Hello, we recently did a lab in our chemistry class to analyze an Unknown amount Calcium Carbonate which was titrated with EDTA. Our titration results were: mass of the unknown CaCO3 was 0.172 g and the mL of EDTA added was 30.7. How do I find the percent mass of Ca?

Chemistry

what are the other chemistry forms present in the dichloromethane solution besides the normal neutral forms for benzoic acid and quinine? (benzoic acid,pKa 4.2; quinnie, pKa 8.5)

English

Can you please check these sentences for me? Thank you very much. It is really urgent! 1) She was looking at the people sitting at the cafè while she was driving. 2) She was listening to music on her earphones while she was running in the park. 3) She was looking at a mobile ...

chemistry

Greg reacts 5.0 moles of hydrochloric acid(HCL)with 1.5 moles of barium hydroxide(Ba(OH)2).Which reagent is the limiting reagent, and which is in excess?If the reagent runs to completion,how many moles of barium chloride(BaCl2)will be produced? CAN SOMEONE PLEASE HELP ME....

chemistry

What is the concentration of the Mg2 ion in solution when [CO3-2] = 0.25M given that the Ksp= 6.82 x 10-6 for the following reaction MgCO3-------->Mg +. CO32- Chemistry - DrBob222, Friday, November 11, 2011 at 5:34pm Ksp = (Mg^2+)(CO3^2-) Substitute 0.25M for CO3^2- and ...

soil chemistry

Can someone please help me answering this question regarding soil chemistry? A sandy soil has a CEC = 5 meq/100g and a K saturation = 6%. An alfalfa crop yields 5 ton/ac/yr at 3% K. Calculate initial exchangeable K and estimate final exchangeable K. Where did the additional K ...

Finance

4.A thirty year US treasury bond has a 4.0 percent interest rate.In contrast, a ten year Treasury bond has an interest rate of 2.5 percent. A maturity risk premium is estimated to be 0.2 percentage points for the longer maturity bond. Investors expect inflation to average 1.5 ...

math

in an examination, 31 candidate passed chemistry, 29 passed physics and 3 failed both subject. if 50 candidate sat for the examination, how many of them passed chemistry only?

Math

First student bought art, math and history books for $72. a+m+h=72 Second student bought art, chemistry and history books for $80. a+c+h=80 Third student bought chemistry, math and history books for $61. c+m+h=61 Fourth student bought art, math and chemistry books for $57. a+m...

Chemistry

3. A chemistry student makes up a 0.10 M solution of NaF(aq) and finds the pH to be 8.09. a. Explain why the presence of F- in this solution affects the pH. b. Write out the acid/base equilibrium equation for the reaction of F- with water. c. Use the measured pH value to solve...

Science! URGENT

Bacteria can reproduce through asexual or sexual reproduction. Environmental conditions for a particular bacteria species are good and the bacteria are thriving. Which form of reproduction will the bacteria most likely use? A. The bacteria will most likely reproduce through ...

bio101

2. Find a media piece—article, video, presentation, song, or other—that recognizes the fundamental concepts of chemistry in biology. Include the link or reference citation for the piece and describe how it helped you better understand how fundamental concepts of chemistry ...

Chemistry

At what initial concentration would a solution of acetic acid (ka=1.8x10^-5) be 2% ionized? Thanks Responses Chemistry - DrBob222, Thursday, February 12, 2009 at 10:00pm Let's call acetic acid HAc. Then the ionization is HAc ==> H^+ + Ac^- We will call the initial concn of ...

Biology---Urgent

14. Surface area is an important factor in limiting growth cell because a. the cell may become too large to remove enough wastes. b. materials can't enter the cell if it's too large c. the cell can burst if the membrane becomes too large d. waste products can't leave the cell ...

chemistry

We had a Chemistry lab for buffer system, we used HCl and NAOH. We did a graph ( PH vs ml of HCL and NaOH, we told to estimate the buffer capacity using the graph. How to do this?

Chemistry

according to the bohr model of the hydrogen atom, what is the closest an electron can get to the nucleus? What is the farthest it can get from the nucleus? ( if the latter answer seems absurb, it might amuse you to know that it is the same value predicted by present-day ...

English (URGENT) Please :'(

I have trouble understanding of this article and how to answer the questions given. I just started new to school in Toronto; I was living in Turkey for Years So I do please to take your time to look and examine my homework. I greatly appreciate your patience and time and ...

Chemistry

In what directions (on the periodic table) does atomic size increase? As you go down in a group, size increases, and as you go LEFT size increases. Size decreases as one goes right within a period. http://www.sparknotes.com/chemistry/fundamentals/atomicstructure/section3.rhtml...

science

What are 3 chemical properties of iron and 2 chemical properties of sodium? http://chemistry.allinfoabout.com/periodic/fe.html http://chemistry.allinfoabout.com/periodic/na.html Thanks. That helped a little.

Physics URGENT!!!

A wheel has a radius of 3.5 m. How far (path length) does a point on the circumference travel if the wheel is rotated through an angle of 71.0°? B) A wheel has a radius of 3.5 m. How far (path length) does a point on the circumference travel if the wheel is rotated through an...

Biology URGENT

Where can i find the Scientific Name of the Phyla/class of Eubacteria, Cyanobacteria, and Prochlorbacteria? Since this is not my area of expertise, I searched Google under the key words "Eubacteria phylum" to get these possible sources: (Broken Link Removed) (Broken Link ...

Chemistry

When someone buys fish at the fresh fish market, they should smell the fish to test for freshness, the less “fishy” the smell the fresher the fish. I am supposed to explain the source and chemistry, including reactions, structures, and names of the compounds, behind the ...

MATH

Please help me with these problems. Work and answer is appreciated! :) thanks. 1. Find on the interval theta is greater than or equal to 0 and less than 2pi; then find the general solution: 5tantheta+1=-2.89 16cos^2theta-6=3 6sin^2theta+sintheta=2 costheta=.84 2tanx=7 2.Find ...

chemistry

how many grams of sodium carbonate are needed to prepare 0.250 L of an 0.100 M aqueous solution of sodium ions? well normally you go moles=grams/molar mass than M= moles/L but when looking for grams? what do you do........multiple .250 by .100 than divide by the molar mass of ...

statistics.urgent please help..

A local college cafeteria has a self-service soft ice-cream machine. The cafeteria provides bowls that can hold up to 16 ounces of ice-cream. The food service manager is interested in comparing the average amount of ice-cream dispensed by male students to the average amount ...

Chemistry

Could someone please check my Chemistry homework? The molecular formula for cisplatin, a chemotherapy agent, is PtCl2(NH3)2 (The numbers are all supposed to be subscripts) 1. What is the molar mass of cisplatin? Ans: 300.06 g/mol 2. How many moles of hydrogen atoms are in one ...

chemistry

So I have to make a green cleaner for a project in chemistry. I think my ingredients should be: vinegar, salt, water, and lemon juice. But I don't know how I would write that exactly as a chemical formula. How could I write a chemical equation if I have 4 reactants? I can try ...

chemistry

In a chemistry experiment, a student measures the density of iridium (Ir) metal as 21.52 g/cm3. The actual density of Ir metal is 22.65 g/cm3. What is the percent error of the student's measurement?

Physics!!! please help... URGENT

Directions: Consider the following scenarios ignoring the effects of gravity: 1. You are the capitan of a spacecraft traveling in the far reaches of outer space, a great distance from any other body. Unexpectedly your radar indicates a meteor on a collision course with your ...

Chemistry

A flask of known volume was filled with air to a pressure of 3.6atm. This flask was then attached to an evacuated flask of known volume and the air was allowed to expand into the flask. The final pressure of the air (in both flasks) was 2.7atm and the volume of the second ...

chemistry

Here is a reaction: 2Al+3H2SO4--->Al2(SO4)+3H2 determine the oxidation numbers of each element in both the rectants and the products of this oxidation reduction reaction of aluminum and sulfuric acid? Which element is oxidized in this reaction? Which element is rduced in ...

Chemistry

Balance the equation: NO2- (aq) + Al (s) --> NH3 (g) + AlO2- (aq) (basic solution) ** please note the "2-" on the NO2- and AlO2- are not subscripts, they are the charges. I missed a few classes in Chemistry and find myself lost. I have tried to learn these equations with ...

science very urgent help?

Susan has heard that taking an over-the-counter ‘energy’ pill, which contains as much caffeine as a strong cup of coffee, makes people feel alert and ‘speedy’. She wonders if taking this pill will make a difference to the reaction times of people doing an online ...

chemistry.......chemistry

what color did your glass-stirring rod emit ? what does this indicate about your glass-stirring rod?

chemistry

Sodium bicarbonate is often used to neutralize acids, such as the following reaction: NaHCO3 + HCl ---> NaCl + H20 + CO2. What is the normality of a sodium bicarbonate solution containing 5.08 g NaHCO3 in 150.0 mL solution? this chapter in chemistry is really confusing and ...

Chemistry

Convert a pressure of 23.8 in. Hg into kilopascal. Ok so I looked up kilopascal and it Said 1 Kpa = 1000 pa So I began to set it up like this 23.8 / 29.2 x1000 am I correct Chemistry - DrBob222, Thursday, October 13, 2011 at 1:48pm I don't think that will get it. I would go ...

Chemistry

I need help with a question about chemistry!!!!!!!!!!! I know that motor oil comes in various grades but is it a homogeneous mixture or a compound? Motor oil, as used for lubrication in cars and other such devices, is a homogeneous mixture. It is mostly oil but it has ...

chemistry... HELPP

Chemistry Equilibrium Constant PLEASE Help!? In an experiment, equal volumes of 0.00150 M FeCl3 and 0.00150 M NaSCN were mixed together and reacted according to the equation: Fe3+ (aq) + SCN– (aq) <--> Fe(SCN)2+ (aq) The equilibrium concentration of FeSCN 2+(aq) was 2....

Spanish #1 (URGENT)

Can someone please check my work? Look at the words in the vocabulary list and write them in the appropriate column. Items in word bank may be used more than once. las cortinas el armario el espejo el televisor el comedor la cómoda la cama el sofá la lámpara EL COMEDOR el ...

Organic chemistry: dehydrohalogenation

Hello. I know you guys don't do organic chemistry but because I got so much help from you guys in general chemistry, I was wondering if you guys can help me out again. :P Here's my question. In dehydrohalogenation, how do you know whether a reaction is E1 or E2? My textbook ...

Help Please! (URGENT)

My previous post didn't post properly so heres a new one. Can someone please check my work? James:But we’re so good together, Susan:We were good together. I’m sorry, but I think we should break up. James:(Silence) Susan:James? James:You think we should break up. (Sighs) I ...

Chemistry

My teacher gave us the answer to a chemistry problem and i cannot figure out how she got the answer. Can you help me work out this problem so i can better understand it. A gas under an initial pressure of 0.60atm is compressed at a constant temperature from 27L to 3.0L. The ...

Chemistry

I'm doing a lab in chemistry and I need help with a question, here is my data: Mass Before: 26.4 g After burned: 26.25 g Total Mass burned: .15 g 1. Calculate the mass of oxygen that was consumed while the candle burned. I think I need to use mole equations and that kind of ...

Chemistry

When titrating 50.0 mL of 0.10 M H2SO4 with 0.10 M NaOH, how many mL of NaOH will you have added to reach the 1st equivalence point? I am confused... What H2A problem? Chemistry-Dr.Bob222 - DrBob222, Tuesday, April 12, 2016 at 1:49am Refer to the H2A problem above BUT you only...

Chemistry

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.43 kg m-3. Under these conditions the total surface area of the balloon is 0.68 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...

Chemistry Help

Good morning, I would like to ask some questions. 1. Is KNO subscript 3 named potassium nitrate 2. Is NaOH named sodium Hydroxide 3. Cu(No subscript 3) subscript 2 named Copper(II) nitrate 4. PCl subscript 3 named phosphate trichloride 5. Can you help me create chemical ...

Chemistry

If you add 0.35grams NaF to 150mL of a 0.30M HF, what is the pH of the resulting solution? To start off would I use the value of 1.4e-11 for F^-^ and 7.2e-4 for HF? Chemistry(Please help) - DrBob222, Tuesday, April 10, 2012 at 12:04am This is a buffer problem. pH = pKa + log(...

Chemistry

In an organic chemistry lab, why is the organic layer usually the upper layer in the separatory funnel while the aqueous layer is usually the bottom layer?

Counting and Probability

Hi! I need urgent help for these questions here. They have a deadline for today and I have no idea how to solve them (a). Suppose we have a bag with 10 slips of paper in it. Eight of these have a 2 on them and the other two have a 4 on them. What is the expected value of the ...

Spansh #2 (URGENT)

Can someone please check my work? Julieta's friends all have different personal tratis. Complete the sentences below using the verb in parenthesis. 1. Maria <es> intelegente. (ser) 2. Julio y Marcos <están> en Ecuador. (estar) 3. Norma y yo <estamos> ...

chemistry

Gasohol contains ethanol (C2H4OH)(l), which when burned reacts with oxygen to produce CO2(g) and H2O(g). How much heat is released when 12.5g of ethanol burns? C2H5OH(l) + 3 O2(g) --> 2 CO2(g) + 3H2O(l) Delta H = -1368kJ Chemistry - DrBob222, Wednesday, May 19, 2010 at 9:...

Chemistry

A chemistry laboratory of an experience is being conducted. The pressure is 0.9 atm and the temperature is 18°C. One of the steps of the experience requires the combustion of 500 mL ethanol (Density=0.78 g/mL). Whereas the burning of this amount of ethanol does not ...

Chemistry

For a chemistry lab, I have to calculate the heat of combustion of paraffin wax. So how would I do that? And for the second part of the lab, I have to calculate the heat of fusion of ice from my data. How would I do that? I'm kind of confused so can I get a bit of guidance.

Urgent everything

Answer as many possible please! 12X13+167-34X56X47= What does bipartite graph mean? When was Judy Blume born? How is 2 negative 1 equals 0? Is Sheila a german name? Thats some hard questions for a year four like me.PLEASE HELP ME Here's a link to help you with your Judy Blume ...

chemistry placement exam

has anyone taken a chemistry placement exam prior to their 1st year of college? what's it like? look up chemistry placement exam on yaahoo and there are a whole lot of websites that talk about what you are asking! hope this helps! You might browse these rays: http://www.google...

chemistry

I did a chemistry lab on polarimetry where we separated two enantiomers into individual salts and then used a polarimeter to determine the specific rotation and optical purity. What is the relationship of the proline salts to one another? i said that being enantiomers, they ...

math urgent please

Petr has a cylindrical block of wood od diameter 6 cm and height 18 cm. He glues the base to a board, but wants to paint the rest of the block. He wants to paint the bottom half of the wood black and the top half white. a) Calculate the surface area of the block that Peter ...

Calculus (Urgent Help)

Okay, I need major help! Can someone tell me if these statements are true or false ASAP please. Thank you. 1. If ƒ′(x) < 0 when x < c then ƒ(x) is decreasing when x < c. True 2. The function ƒ(x) = x^3 – 3x + 2 is increasing on the interval -1 < x < 1...

Chemistry pls help

I have a chemistry question Please advise how do I prepare 1L of 75% H2SO4 from concentrated H2SO4 (98% of density 1.84g/ml)? Do you have an equation which i can use? Someone gave me the following equation but I do not understand it. Vx1.84x0.98={(1000-V)+ 1.84V}0.75 where V= ...

math

Riena has six unmarked CDs in a box, where each is dedicated to exactly one of English, mathematics, French, American history, chemistry, and computer science. Answer the following questions: a. If she chooses a CD at random, what is the probability she chooses the English CD...

chemistry

A Biology student wants to know if Mountain Dew will make plants grow faster than water. As a Chemistry student, you have agreed to assist in the planning of the experiment to make sure the student designs a valid experiment. 1) What is the experimental question? 2) What is ...

chemistry

When the conductivity is at a minimum, what must be true about the amount of Ba(OH)2 compared to H2SO4? The Ba(OH)2 dissociates as Ba+2 + 2 OH-. H2SO4 dissociates as 2 H+ + SO4-2. Why does it not conduct at this low point? Why does it conduct more before and after this minimum...

chemistry

can you please give me one practical application of analytical chemistry in being a medical technologist? i know it will determine the separation event happening on the lab test... but is that already a practical application? or i have to cite a deeper example? please give me ...

chemistry

when x gram of carbon is completely burnt in certain amount of oxygen y gram of carbondioxide is form.what mass of Co2 will be produced when 2x gram of carbon is burnt in z gram of oxygen. which law of chemistry will help me to find the answer

chemistry ---------chemistry

What color did your glass -stirring rod emid ? what does this indicate about glass- strirring rod ? Ans: galss stirring rod emids orange . but i don't know the ans 2 .

chemistry

Good day to everyone My class has just started a "Chemistry systems in Equilibrium" unit and I have a question I would like answered if possible, I would truly appreciate this. My Question: How will the following system change when F2(g) is added to a sealed vessel containing ...

English

What could be the theme of this poem? What I would like to know is the subject matter and also what could be the author's commentary on the poem. Sonnet - Silence by: Edgar Allen Poe There are some qualities- some incorporate things, That have a double life, which thus is made...

polymer-Crosslinking Chemistry

Explain why a polymer such as polybutadiene can be cross-linked, however a polymer such as polyethylene cannot be cross-linked. Make reference to what it is about the chemistry of the repeating units that allows for the formation of cross-links.

Chemistry

Hello everybody, I'm having difficulty understanding the rationalization behind the strengths of Bronstend Lowry acids and bases and my textbook isn't too helpful. Can someone please expalin to me: (1) What exactly is effective negative charge density? (2) how does ...

8th Grade Chemistry

This is from the Glencoe book Chemistry, Book L. Unlike sodium and chlorine, some atoms becomre more stable by sharing_______, forming______________rather than charged__________. The bonds in a molecule of oxygen are _______ _______ bonds, while the bonds in molecule of water ...

Chemistry

Why is it that copper (II) sulfate with barium hydroxide --> copper hydroxide (solid) + barium sulfate (solid)? According to the solubility rules given to me by my professor, both are insoluble, and therefore should be labeled as solids. Is there something I'm missing here...

Chemistry

Why is it that copper (II) sulfate with barium hydroxide --> copper hydroxide (solid) + barium sulfate (solid)? According to the solubility rules given to me by my professor, both are insoluble, and therefore should be labeled as solids. Is there something I'm missing here...

university chemistry

this is for a chemistry laboratory experiment called "how much caffeine is there in instant coffee" What should be the pH of the aqueous layer to extract caffeine? There are three aqueous solutions that you may choose from. A. pH >14, using 2.5 M NaOH (aq) B. pH 1, using 0....

Chemistry - HELP IGCSE

I have a chemistry exam tomorrow and I don't get the double bonding in covalent bonding I tried many websites , textbooks and other books and yet nothing worked Can someone please explain it clearely and in a simple way and please don't put any links for websites ca use ...

chemistry

solve Ka for HX => H^+ + X^- given 0.1M LiX at pH=8.9 Chemistry - DrBob222, Tuesday, March 30, 2010 at 6:32pm LiX(aq) ==> Li^+(aq) + X^-(aq) X^- is a base and hydrolyzes in water to X^- + HOH ==> HX + OH^- Make an ICE chart and substitute into the following: Kb = (Kw/...

Science (Chemistry)

I'm not sure how to do a couple of problems on my chemistry worksheet. Can you please help me? You dissolve 0.00902 g of naOH in enough water to make 1000 mL. What is the Ph of this soultion. What is the molarity, pH, and pOH of 5.00 of naOH in 750.0 mL of soultion. I know how...

Chemistry

The question is: Isotonic saline is a 0.9% (g/100ml) solution of salty water. You are asked to make up 2L of isotonic saline. How much salt should you weigh out? I got the answer of 18g with the following working: 9 ÷ 1000(ml) x 100 = 0.9 Therefore 9% of 1000ml (1L) is 9g ...

chemistry

A chemistry student weighs out 0.172 grams of acrylic acid (HCH2CHCO2) into a volumetric flask and dilutes to the mark with distilled water. He plans to titrate the acid with 0.1800 moles/liter NaOH solution. Calculate the volume of NaOH solution the student will need to add ...

GREAT GATSBY URGENT!!!!!!!!

explain a theme in the great gatsby, multiple paragraphs What theme do you want to explain? Please post your answer here and someone may be able to critique it for you. tragedy and the american dream http://www.sparknotes.com/lit/gatsby/ http://www.gradesaver.com/classicnotes/...

geo

Hi... I need some URGENT help with my geography essay, I'm suppose to have three reasons to why canada is the best country and I'm looking for a 3 strong arguments ... i have 2 already down , economy and physical geography . I need to have 11 paragraphs in total. so that means...

Chemistry

I was given a chemistry worksheet that said the following Solutions mixed at the BLANK level Colloids Mixed at the BLANK level Suspensions mixed at the BLANK level What do you suppose the blanks could be? Thank you.

Chemistry

The energies, E, for the first few states of an unknown element are shown here in arbitrary units. n 1 E -11 n 2 E -5 n 3 E -2 n 4 E -1 n ... E ... n infinite E 0 A gaseous sample of this element is bombarded by photons of various energies (in these same units). Match each ...

algebra

in a class of 30 students , there are 22 students who study chemistry but not physics, 4 who study physics but not chemistry and who study neighter chemistry nor physics. how many students in the class study physics

Chemistry

I'm stuck on this one problem in Chemistry: A student measures the mass of an object as 2.32 grams and its volume as 34.56mL. The student then calculates the density to be 0.067129629. There are two things wrong with the students value for density. What are they? Now when I ...

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