# chemistry! URGENT

61,843 results, page 28
1. ## Chemistry

A teacher prepares a saturated NaCli solution at 55 Degree C. What is the % by mass 9m/m0 of this solution? what is the concentration of this solution expressed in ppm? What is the molality of this solution? If the density of the solution is 1.07 g/ml,
2. ## chemistry

I have a lot of trouble doing this chemistry exercise It says: The altitude of the lake affects the solubility of oxygen in lakes high in the alps. if the solubility of O2 from the air is 7.89 mg/L M at sea level and 25C, what is the solubility of O2 in
3. ## Chemistry

Explain in terms of forces between structural units why H2O2 has a higher melting point than C3H8. Also, which of the following has a lower melting point? NH3 or AsH3 C3H7OH or C2H5OCH3 I know that this has to do with hydrogen bonding. Can you possibly
4. ## ap chemistry

ap chemistry - an, Tuesday, January 6, 2015 at 12:59am HELP ME WITH THIS ONE WHEN DONE WITH THE OTHER THX calculate the concentration of CO2 in a soft drink after the bottle is opened and equilibrates at 25C under a CO2 partial pressure of 0.0003 atm. c=KP
5. ## Calculus (urgent!!)

Please answer the following questions about the function f(x)=e^(-0.5x^2) Instructions: If you are asked to find x- or y-values, enter either a number, a list of numbers separated by commas, or None if there aren't any solutions. Use interval notation if
6. ## chemistry

What mass in grams of potassium hydroxide is cntained in 500 mL of solution that has a pH of 11.5? For Further Reading chemistry - DrBob222, Sunday, April 6, 2008 at 12:09am pH = 11.5 pOH = 14 - 11.5 = 2.5 pOH = -log(OH^-) ] 2.5 (OH^-) = ?? KOH ==> K^+
7. ## chemistry

so we did a chemistry lab to find the relationship between temperature and volume or charle's law. In the experiment, i got t1v1=372K, 267.2 cm^3 t2v2=277K,169.1 cm^3 so i graphed that THen they told us to chose 2 other points from that line, TaVa and TbVb
8. ## chemistry

An insulated beaker contains 250.0 grams of water at 25oC. Exactly 41.6 g of a metal at 100.0oC was dropped in the beaker. The final temperature of the water was 26.4oC. Assuming that no heat is lost in any other way, calculate the specific heat of the
9. ## Chemistry

Can you please someone check my answer for me? I don't know how to start thses answer. Chemistry is not my things. Please give me answers. :( a)Determine the number of grams in 0.750 moles of the compound Iron(II)phosphate: Fe3(PO4)2. Answer: ? b)How many
10. ## chemistry

I'm sorry, but this is a re-post. I couldn't find the original post;-( so, does anyone have any suggestions for helping a student make a passing grade in college chemistry? She took it twice and didn't pass. Any suggestions would be appreciated. I thought
11. ## Chemistry

please help! Is RTP in chemistry (thermochemistry and electrochemistry) referring to room temperature of 25degreeC (or 298K) and 1atm, or 20degreeC (293K) and 1atm? In my lecture notes on gas law, they stated RTP refers to 25degreeC, but in my electrochem
12. ## English

Hello! I will type 2 exercises from the lesson I am teaching on Wednesday-english as a foreign language - 8th graders ( it will be graded) I need you to help me with some ideas. It says: LEAD- IN: A Here is a list of some natural sciences: BIOLOGY

1) Nitrosyl chloride (NOCl) decomposes at high temperature. The equation is 2 NOCl (g) -> 2 NO (g) + Cl2 (g) at 227oC Using delta Ho = 81.2 kJ and delta So = 128 J/K, calculate the value of the equilibrium constant for this reaction. I do not know how
14. ## 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.
15. ## Spanish #2 (URGENT)

Can someone please check my work? Write a complete sentence using the elements below and replacing the words in parentheses with a direct object pronoun. modelo: Mabel/hablar (yo) Mabel me habla. 1. Jorge y Ernesto/quieren cerrar (su tienda) temprano Jorge
16. ## Chemistry

Organic chemistry: an attempt at synthesizing a certain optically active compound resulted in a mixture of its enantiomers. The mixture had an observed specific rotation of 11.0 degrees. If it is known that the specific rotation of the R enantiomer is
17. ## 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)
18. ## Chemistry/English

In chemistry we are writing a paper about an inventor.. We have to have some back ground info.. what they invited. how there time affected there inventions and if there inventions where a great success and so on so forth. What would be a good way to set

20. ## Chemistry

Thank you for your help. I did want to clarify why you are only calculating the Molar Mass for H2 and not the molar mass for H2O (or even H2O2). I'm not sure why you did this. Please clarify. See below: The following reaction represents the decomposition
21. ## math

A textbook store sold a combined total of 462 biology and chemistry textbooks in a week. The number of biology textbooks sold was two times the number of chemistry textbooks sold. How many textbooks of each type were sold?
22. ## math

A textbook store sold a combined total of 315 physics and chemistry textbooks in a week. The number of physics textbooks sold was two times the number of chemistry textbooks sold. How many textbooks of each type were sold?
23. ## chemistry

i am trying to find the average rate of h2? from mastering chemistry home work. part a answer was 0.027m/s and part b answer was 0.054m/s. i cant find part c home answer
24. ## probability

The probability that a student passes Biology is 0.35 and the probability to pass Chemistry is 0.63. If the probability to pass both Biology and Chemistry is 0.4, what is the probability that he will pass either Biology or Chemistry?
25. ## Chemistry

You are a work study student in our chemistry department. Amy, your supervisor has just asked you to prepare 250ml of 2.00M H2SO4 solution for tomorrow's undergraduate experiment. The Stock Solutions cabinet is under the Stockroom Explorer. You will find
26. ## Chemistry due soon

I am having some chemistry problems. 3. The graph compares the 1s orbital energies for the F atom (Z = 9), the Ne+ ion (Z = 10), and the Na++ ion (Z = 11). (the graph shows F having an Orbital Energy of 692.45, Ne+ with 47.74, and Na++ with 33.52) a. How
27. ## chemistry due soon

I am having some chemistry problems. 3. The graph compares the 1s orbital energies for the F atom (Z = 9), the Ne+ ion (Z = 10), and the Na++ ion (Z = 11). (the graph shows F having an Orbital Energy of 692.45, Ne+ with 47.74, and Na++ with 33.52) a. How
28. ## chemistry

I am a freshman in college, and am taking a placement test soon, but haven't seen chemistry since 10th grade. I'd appreciate any help I can get from anyone here to help me solve this problem: Hydrogen and sulfur chemically combine to form the gas hydrogen
29. ## chemistry

I am having some chemistry problems. 3. The graph compares the 1s orbital energies for the F atom (Z = 9), the Ne+ ion (Z = 10), and the Na++ ion (Z = 11). (the graph shows F having an Orbital Energy of 692.45, Ne+ with 47.74, and Na++ with 33.52) a. How
30. ## Chemistry

I am having some chemistry problems. 3. The graph compares the 1s orbital energies for the F atom (Z = 9), the Ne+ ion (Z = 10), and the Na++ ion (Z = 11). (the graph shows F having an Orbital Energy of 692.45, Ne+ with 47.74, and Na++ with 33.52) a. How
31. ## Chemistry

I am having some chemistry problems. 3. The graph compares the 1s orbital energies for the F atom (Z = 9), the Ne+ ion (Z = 10), and the Na++ ion (Z = 11). (the graph shows F having an Orbital Energy of 692.45, Ne+ with 47.74, and Na++ with 33.52) a. How
32. ## chemistry hellllllllllllllllllp

Oxidising and reduction- Chemistry? Oxidation and reduction can be described as the loss and/or gain of electrons from an ion or atom (species) in a chemical reaction. For the following aqueous reaction, select the species that is oxidized and similarly
33. ## chemistry

I am having some chemistry problems. 3. The graph compares the 1s orbital energies for the F atom (Z = 9), the Ne+ ion (Z = 10), and the Na++ ion (Z = 11). (the graph shows F having an Orbital Energy of 692.45, Ne+ with 47.74, and Na++ with 33.52) a. How
34. ## Chemistry-pls help

I refer to the following question. Is my explanation correct, that step two C6H14(g)--> 6CO2(g) + 7H2O(g) can be considered combustion reaction? Thank you! Posted by jan on Tuesday, March 31, 2009 at 10:28pm. C6H14(l)->C6H14(g) ->6CO2(g) + 7H2O(g)
35. ## planning

Ms. Sue, you told me last time to search up my college to see what courses are required for hygienist, and so this is what I got. 2. The course choices that I make today lead to the fulfillment of this dream by them providing all the knowledge that I need
36. ## chemistry ------------ chemistry -------

when you were heating milk on the stoven you accidentally spilled some milk on the burner . what color would you see ? why would you see that color? My answer : Intense yellow . because milk has sodium , sodium is intense yellow . is this right ?
37. ## Chemistry

When 50 grams of hydrocarbon X are burned with oxygen the products are carbon dioxide and water. If 65 grams of water and 100 grams of carbon dioxide are produced, how many grams of oxygen were needed for the reaction? This was a question on my chemistry
38. ## Organic Chemistry

Hello! I was looking for some advice on my organic chemistry lab. We were supposed to separate and identify a solid mixed into a liquid. I found and have confirmed my liquid is acetone by distilling it out of the solid. The solid then turned into a whitish
39. ## Chemistry

I wanted to now what is the molecular geometry of SeBr4, because I believe is a trigonal bipyramid...but I am not sure...please help me.... I thought it was a see-saw shape. See http://www.stolaf.edu/depts/chemistry/mo/struc/explore.htm You can see SeF4,
40. ## 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
41. ## chemistry ........................chemistry

Sodium Na+ Intense yellow Barium Ba++ Green Calcium Ca++ Brick red Copper Cu+ or Cu++ Blue-green Strontium Sr++ ? Lithium Li+ ? Sodium and potassium mixture Na+&K :yellow light Observations using the cobalt glass filter Sodium & potassium mixture
42. ## chemistry/stiochiometry

for instance Will write a problem. Now, I don't just want the answer, I want to know how to know which substances, and processes in steps and don't spare detail. I am going through high school chemistry. somehow i PAST MY Stoichiometry test. now i am ready
43. ## MATHS

in a class of 60 students,the number of students who pass biology is 6 more than the number who pass chemistry.every student passed at least one of the two subject.how many pass in only biology.how many pass in only chemistry.
44. ## chemistry

Chemistry problem: given: serving size 0.5 oz, 4g fat/ serving, 140 mg sodium/serving. a) box has net weight of 8oz how many crackers per box? i got 96. b) if you ate 10 crackers how many ounces of fat are you consuming? i got 0.23 ounces. c) how many
45. ## CHEMISTRY! HELP

1. Given the following set of quantum numbers: 3py -1/2. A chemistry student claims that this represents a peanut-shaped electron. Is she correct? Answer (Am I correct? If not, how?) : She is correct because 3py is a peanut shape with -1/2 being the spin.
46. ## Chemistry

I'm doing online chemistry homework, and the site keeps telling me I have the wrong answer, but I'm not sure what I'm doing wrong. please help? What is the pH of a 0.089M solution of phosphorous acid (H2PHO3) in water? The value of Ka1 for H2PHO3 is 1.600
47. ## Chemistry

Dear sir, madam, I am having a little problem with the solution my chemistry book gives on the following problem: We have a person whose body vitamine C concentration decays according to the following formula: 1500*0,974^t. Question A is no problem, but
48. ## chemistry - pick a polymer

I need to pick a polymer for my science project. It has to be organic and preferably simple. Some that are already taken are: polyethene, polystyrene, PVC, polyacrylonitrile, DDT , nylon.. Thanks a lot it has been really hard for me to find something. I

. Ksp for Fe(IO3)3 is 10-14. Two solutions, one being iron(III) nitrate and the other being sodium iodate, were mixed. At the instant of mixing, [Fe3+] = 10-4M and [IO3-] = 10-5M. What happens? My answer is that a precipitate forms because Qsp > Ksp.
50. ## Animal Physiology HELP!!!!!!!!!!

Please help me!!! What are the answers to these Animal Physiology questions? Urgent..... A decrease in the partial pressure of carbon dioxide in the lungs is referred to as a) Respiratory acidosis b) Hypercarbonia c) Hyperoxia d) Hypercapnia
51. ## Chemistry

I need to determine the "percentage composition unknown" whatever that is. My current data: a) mass of test tube and foil cover: 7.5323 g b)temp of water bath: 375.65 K c) mass of test tube and foil and gas as sample: 7.5423 g d) barometric pressure:
52. ## Math

I need urgent help with these 3 math problems 1. Margaret painted a mural for St. Patrick’s Day and mixed her own green paint. She mixed 3 parts yellow paint with 2 parts blue paint to create green paint. Maureen wanted to also paint a mural with the
53. ## Chemistry

I am completely lost in chemistry. Everything the teacher says sounds like a different language to me and I am usually really good in the class. Can someone help me do this problem please? An element "E" is present as 10E (The 10 is like an exponent to the
54. ## Chemistry and @DrBob222

Sorry for the mix up -- here's what DrBob222 posted for the Chm or Chemistry question: What subject is CHR? If you don't label the subjects correctly the proper tutor won't know you need help. This question can't be answered as posted. You need the
55. ## chemistry

Captain Kirk, of the Starship Enterprise, has been told by his superiors that only a chemist can be trusted with the combination to the safe containing the dilithium crystals that power the ship. The combination is the pH of Solution A described below,
56. ## Chemistry

I was not the person who wrote that question last night? Chemistry - DrBob222, Wednesday, November 15, 2006 at 7:24pm Yes, it is possible in some cases. For example, CoCl2 is blue in the unhydrated form and pink in the hydrated form. As a kid, I used a
57. ## chemistry

I want to make sure I am correct in classifying whether the following properties of hydrogen are chemical or physical. thanks 1. hydrogen will burN in in oxygen to form water. CHEMICAL 2. hydrogen does not support combustion. CHEMICAL 3.hydrogen is usually
58. ## Chemistry-help

How does a "chemical for synthesis" compare with the same chemical(ACS grade)when used in analytical testing? Posted by candy on Tuesday, January 11, 2011 at 2:10pm. Chemicals are supplied in different grades,e.g. ACS,AR...etc.What do we mean when we say
59. ## VERY URGENT, HELP!

Consider a simple economy consisting of only four firms. Firm A, a mining enterprise, extracts iron ore. Firm B, a Steelmaker, produces steel sheets. Firm C, a carmaker, makes automobile while Firm D produces automobile tires. In 2016, firm A extracts
60. ## Chemistry *DrBob222

Posted by Jamie on Sunday, June 20, 2010 at 3:36pm. You are given three test tubes that contain colourless liquid. One test tube contains benzene, another contains ethanol, and the third contains 2,4-hexadiene. Design a procedure that will tell you the
61. ## Geography. plz help its urgent.

Ok, so i was given an essay question to do. In a well developed essay, list and explain the three types of immigrants that Canada accepts. Explain why the Canadian Government would want to allow such immigrants to enter into Canada. Pleasee help. I know
62. ## chemistry

A 100-watt light bulb radiates energy at a rate of 100 J/s. (The watt, a unit of power or energy over time, is defined as 1 J/s.) If all of the light emitted has a wavelength of 525 nm , how many photons are emitted per second? okay so i do:
63. ## Chemistry

Posted by Angeline on Monday, April 20, 2009 at 5:35pm. A few questions...how many grams are in 48.7x10^24? I don't know how to convert atoms to grams. I can do moles to grams or moles to atoms, but not atoms to grams. My other problem is how do you
64. ## 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
65. ## Econ URGENT HELP!

Consider a simple economy consisting of only four firms. Firm A, a mining enterprise, extracts iron ore. Firm B, a Steelmaker, produces steel sheets. Firm C, a carmaker, makes automobile while Firm D produces automobile tires. In 2016, firm A extracts
66. ## Econ VERY URGENT, HELP!

Consider a simple economy consisting of only four firms. Firm A, a mining enterprise, extracts iron ore. Firm B, a Steelmaker, produces steel sheets. Firm C, a carmaker, makes automobile while Firm D produces automobile tires. In 2016, firm A extracts
67. ## URGENT ALGEBRA 2

identify the vertex and the axis of symmetry of the graph for the function y=3(x+2)^2 a.vertex(2,-3 axis of symmetry x=2 b.vertex(-2,-3) axis of symmetry x=-2 c.vertex(2,3) axis of symmetry x=2 d.vertex(-2,3) axis of symmetry x=-2 identify the maximum or
68. ## chemistry

You suspect your trophy for the “Freshman Chemistry Award” of mass 122.6 g is not composed of pure gold and you decide to test this by immersing the trophy into a graduated cylinder containing a liquid shown in Fig. 2A. The result is shown in Fig. 2B.
69. ## chemistry .chemistry

obtanin a piece of comcentrated acetic acid and 10 ml of di- water . bring the content of this beaker to a gentle boil using a low flame on the Bunsen burner . boild for about 3minutes , alow to cool and then remove the steel wool ball . what is formula?
70. ## urgent!!

Summer Swimming Selection The municipal swimming pool in Nicetown has three different ways of paying for individual open swimming. Evan is trying to decide which way to pay. • Early Pay: Pay \$45 before Memorial Day; swim any number of days • Deposit
71. ## chemistry

If your car gets 21.4 mpg, how many L of CO2, will you release into the atmosphere, if you drove the 1280miles from Towson University to key West Florida for a much needed break after taking Chemistry 121? Assume 1.05atm and 17.0C. What would your carbon
72. ## chemistry

If your car gets 21.4 mpg, how many L of CO2, will you release into the atmosphere, if you drove the 1280miles from Towson University to Key West Florida for a much needed break after taking Chemistry 121? Assume 1.05atm and 17.0C. What would your carbon
73. ## chemistry

If your car gets 21.4 mpg, how many L of CO2, will you release into the atmosphere, if you drove the 1280miles from Towson University to key West Florida for a much needed break after taking Chemistry 121? Assume 1.05atm and 17.0C. What would your carbon
74. ## Chemistry

In winemaking, the sugars in grapes undergo fermentationby yeast to yield CH3CH2OH and CO2. During cellularrespiration, sugar and enthanol are "burned" to water vapor andCO2. A) Using C6H12O6 for sugar, calculate ÄH of fermentation and of
75. ## Chemistry

In winemaking, the sugars in grapes undergo fermentationby yeast to yield CH3CH2OH and CO2. During cellularrespiration, sugar and enthanol are "burned" to water vapor andCO2. A) Using C6H12O6 for sugar, calculate ÄH of fermentation and of
76. ## Chemistry

Unfortunately I was hit by the sweep of illnesses going around due to changing whether and missed school today. Thus I missed the notes in Chemistry leaving me completely confuzzled about tonights homework on Dimmensional analysis or Unit Factoring. I
77. ## Chemistry (chromatography)

I had a chromatography experiment for chemistry and here is one of the questions: Did the compounds travel farther in the water or the isopropyl alcohol (rubbing alcohol)? Explain why you think that this is the case. Now, the compounds traveled the
78. ## Organic Chemistry

Hello, I have done an experiment in Organic Chemistry called :SN1 Reaction: Synthesis of t-amyl chloride from t-amyl alcohol, there are some questions that I am unsure about, 1) What are the 2 rules of HCl in this reaction? Can you use NaCl instead of HCl
79. ## Chemistry Dr. BOB

I don't get it!! In winemaking, the sugars in grapes undergo fermentation by yeast to yield CH3CH2OH and CO2. During cellular respiration, sugar and enthanol are "burned" to water vapor andCO2. Write a combustion reaction for ethanol. I need help with
80. ## Chemistry

We did a titration of calcium hydroxide lab in chemistry, once with and once with edta, we have to calculate the solubility for both, and the ksp, for the hcl I did (concentration)*(Volume of hcl used) then that answer divided by two divided by the amount
81. ## ms. sue pls. help me urgent

pls help me if my english is correct in grammar or relevant to the question thank you. question..1.What is meant by “if we are to improve our speaking skills, we must first become more aware of ourselves, our motivation, behavior patterns, and likely our
82. ## Science

How does the silly putty made up of glue gel differ from the silly putty made of soap in terms of texture ? How would the touch be different and why? Chemical structure? .....? Science:Chemistry - bobpursley, Friday, February 21, 2014 at 9:53pm Have you
83. ## Chemistry

Need help with AP chemistry, specifically Acids and Bases The acid ionization constant, Ka, for propanoic acid, C2H5COOH, is 1.3  10 -5 . (a) Write the expression for the acid-dissociation constant, Ka for propanoic acid. (b) Calculate the hydrogen
84. ## DrBob222

I know I posted this but you didn't answer! Please help!!!! Consider the following reaction at 298 K: C(graphite) +2Cl2 (g) -----> CCl4(l) Calculate the following quantities. Delta H: -139 kJ/mol deltaS(sys)=? J/mol*K deltaS(surr)=? J/mol*K
85. ## Managerial Economics- URGENT

The Blue Dragon Restaurant is a new Chinese Restaurant in town. As the only Chinese restaurant in the area, it faces the following daily demand curve: Q = 500 – 25 P Where Q is the number of meals it serves per day and P is the average price of its
86. ## Chemistry

I know mathematically I can write chemical reactions this way but in chemistry can I if now why? 2K + 2(H20) yields 2KOH + H2 2(K + H20) yields 2KOH + H2 can I also do this if not why? 2(CO) + O2 yields 2(CO2) O(2C + O) Yields 2(CO2) I don't see why I cant
87. ## Chemistry

A stressed chemistry student is hyperventilating into a paper bag. The student stops to wipe his brow after a few breaths, and the bag is at 5.7 KPa and the temperature in the lecture hall is 24 °C. The bag is 0.75L full. The student then goes at it
88. ## Chemistry

A stressed chemistry student is hyperventilating into a paper bag. The student stops to wipe his brow after a few breaths, and the bag is at 5.7 KPa and the temperature in the lecture hall is 24 °C. The bag is 0.75L full. The student then goes at it

a stressed chemistry student is hyperventilating into a paper bag. The student stops to wip his brow after a few breaths, and the bag is at 5.7 KPa and the temperature in the lecture hall is 24 degrees C. The bag is 0.75 L full. The student then goes at it
90. ## chemistry

I've been doing organic chemistry and I don't really understand how to draw some isomers. I know how to draw the easier isomers like Butan-1-ol and Butan-2-ol but I don't get how there can be other ones and how to draw them...please help
91. ## Chemistry Lab

In chemistry we are doing a lab that involves crucibles and Mg ribbon, we have three days to complete the lab. Anyways do you think it would be alright to substitute the mass of the crucible we had the first day with the mass of the crucible we had today?
92. ## Chemistry

Can you please someone check my answer for me? I don't know how to start thses answer. Chemistry is not my things. Please give me answers. :( a)Determine the number of grams in 0.750 moles of the compound Iron(II)phosphate: Fe3(PO4)2. answer: 129.68grams
93. ## chemistry

Use the systematic treatment of equilibrium to determine the pH and concentrations of species in 1.00 L of solution containing 0.065 mol citric acid (H3A), 0.025 mol 8-hydroxyquinoline (HB), and 0.040 mol KOH. Consider just acid-base chemistry. Ignore ion
94. ## chemistry

The question I am having trouble with is: Scientists originally were uncertain whether the oxygen gas produced during photosynthesis came from CO2, H2O, or from both. How could radioisotope tracers be used to settle that question? Chemistry - DrBob222 6CO2
95. ## chemistry

Ca + Br2 --> CaBr2 its synthesis and the reason the reaction happens is stable electron configuration but i don't understand why. Responses chemistry - DrBob222, Wednesday, January 21, 2009 at 10:06pm Synthesis because it's two elements combining to
96. ## Chemistry

I am looking at the delta H chart to calculate delta H of reactions. When doing one reaction, I came across a species that was not included in the chart: SiO4. What do I do? There is no SiO4. SiO2 perhaps, OR, you have been asked to calculate a theoretical
97. ## 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.
98. ## English

Urgent! Can someone please look these over? The sentences are very vague (welcome to online schooling, I guess). Some of them are questionable. Please help! Need to write whether the sentence is a "POINT" or "TOPIC" sentence. Point Sentence-Announces the
99. ## math

Emily surmises that the probability that she will pass math or chemistry is .95, the probability of her passing math is .7, and the probability of passing both is .55. Find her estimate of the probability of passing chemistry?