Wednesday

July 23, 2014

July 23, 2014

Total # Posts: 2,967

**Chemistry**

You receive two samples of a substance. After testing, it shows that one sample contains 88% oxygen by mass an 12% hydrogen. The second sample contains 94% oxygen and 6% hydrogen. Is it possible that the two samples are the same? Explain. thanks, I appreciate the help !

**Chemistry**

You receive two samples of a substance. After testing, it shows that one sample contains 88% oxygen by mass an 12% hydrogen. The second sample contains 94% oxygen and 6% hydrogen. Is it possible that the two samples are the same? Explain. thanks, I appreciate the help !

**Organic Chemistry - Melting Point**

You have an unknown with an observed melting point of 90-93°C. Is your unknown compound A with a reported melting point of 95.5-96°C or compound B with a reported melting point of 90.5-91°C? Explain.

**Chemistry**

NiF2(aq)+Fe2(SO4)3(aq) ==NiSO4 (aq) + FeF3 (s) balance each of the following chemical equations. Express your answer as a chemical equation. Identify all of the phases in your answer. Can help me refresh my memory ...

**probability**

A company's records indicate that on any given day, 1% of their day shift employees and 2% of the night shift employees will miss work. Sixty percent of the employees work the day shift. a. What percent of employees are absent on any given day? b. A randomly selected emplo...

**probabilityv**

A school's administrators are concerned about absenteeism at their school and the eect it has on students' grades. The following data were compiled, based on a sample of students. Student's Absent Medium Absent Grade Infrequently Absent Frequently Low 1 9 8 Me...

**Chemistry**

thank you

**Chemistry**

Nitric acid is a component of acid rain that forms when gaseous nitrogen dioxide pollutant reacts with gaseous oxygen and liquid water to form aqueous nitric acid. Write a balanced chemical equation for this reaction. Express your answer as a chemical equation. Identify all of...

**Chemistry**

and I finaly got #1 it is Al2O3

**Chemistry**

I finaly got #2 it is K2O

**Chemistry**

Write a formula for the ionic compound that forms between each of the following pairs of elements. 1. aluminum and oxygen Express your answer as a chemical formula. AlO and Al2O3 and Al2O3 the 2 was the bottom right cornor and I got this message Use subscripts to represent the...

**Chemistry**

thank you so much you are awesome. ;-)

**Chemistry**

whoops Write a formula for the ionic compound that forms between each of the following pairs of elements

**Chemistry**

zink and sulfur Express your answer as a chemical formula. I entered Zn+2,S-2 and it said this to me There is an error in your submission. Make sure you have formatted it properly.

**Chemistry**

THANKS

**Chemistry**

i put 44.3x131.30=5.81659E3 thats the answer it got, so I put it in 3 significant figures. I guess I am really confuss

**Chemistry**

5.81 g is that right

**Chemistry**

What is the mass, in grams, of each of the following? 44.3 mol Xe

**Chemistry**

m= 4.90 g

**Chemistry**

3.57×10−2 mol Ba Express your answer using three significant figures

**3rd grade math**

8 times 493= 3944 using distributive property then solve with array showing the work

**5th grade/ Math**

Your Max (highest number) = 18 Your range is 13 so your minimum number in your set =5 You need the mean to = 12 so all twelve numbers in your set have to equal 144 so that the 12 individual numbers will have a mean of 12 (144/12=12). The mode = 7 - so 7 is going to occur more ...

**Math**

I have a few questions about T-Matrix. In excel, I am suppose to work with powered matrices to construct a weighted T matrix, using a scalar of .7. Does this mean I multiply each of the powered matrices by .7? Or do I power the powered matrices by .7? Or am I completely off ba...

**english - thesis statement**

Based on the reading Wolf-Alice by Angela Carter I need to put together a thesis statement, regarding the development of self identity. Wolf-Alice is a feral child who lived with a pack of wolves. Group of nuns take her in to try to show her human ways (since she couldnt be fi...

**statistics**

Considering that a researcher can test at the <p = .05 (95%), p = .01 (99%), or p = .001 (99.9%) level for statistical significance, how do you use these three levels in relationship to evaluate risk to patients in implementing the decisions based on research findings?

**Algebra**

please show steps solve 9 - (9)squared > 10x - x

**Algebra**

-4 - 2n + 4n > 7 - 4

**Algebra**

Homework help please: algebra inequality 0.3 - 0.5n + 1 is greater than or equal to 0.4

**Physics**

A horse canters away from its trainer in a straight line, moving 120 m away in 11.0 s. It then turns abruptly and gallops halfway back in 4.9 s.

**English**

What would be good sentence for emerald?

**English**

I needed to create sentence containing the phrase "green with envy". I have got two sentences here, but I need help picking out the one that makes more sense. Emily’s new look made her friends green with envy. Emily’s friends became green with envy when the...

**Science**

Thank you Sra! This is for 7th grade science - so it looks as though dynamic condition is a state of constant moving until all parts are equal and static condition is motionless. Do you know if this correct?

**Science**

The state of cellular equilibrium is best described as a dynamic condition, not static. What does this mean?

**American Democray**

The president's role in foreign policy increased largely because: a Congress proved so inept in foreign affairs that the american people demanded a change b America became more of a world poer c of the need to coordinate national economic poicy and foreign policy, a task t...

**Chemistry**

What is the specific heat (in cal) of fat with a degree change from 25 degrees Celsius to 35 degrees celsius? Density of fat = 0.94 g/cm^3

**Math**

Betsy, a recent retiree, requires $6,000 per year in extra income. She has $60,000 to invest and can invest in B-rated bonds paying 13% per year or in a certificate of deposit (CD) paying 3% per year. How much money should be invested in each to realize exactly $6,000 in inter...

**chem**

Po-218 is an alpha emitter with a half-life of 3.0 minutes. If a sample contains 69 mg of Po-218, how many alpha emissions would occur in 6.0 minutes? the answer has to be _________a emmisions (which I have no idea what it means) and I use a chart thing with amount, #H-L, and ...

**Chemistry**

Draw the lowest energy conformation of 3-ethyl-2,4,4-trimethylheptane, depicting the C3-C4 bond on a sawhorse. How would i do this? i am so lost

**geometry**

fine the perimeter of ABCD = 46. AB = x+9, CD= 2x-7

**math**

what does equivalent mean?

**8th grade math**

I understand that part but I'm just not sure when the question asks me what VALUE will make the equation TRUE will it be x=-72? because I don't think that's what there asking me.

**English composition**

Music during slavery: A call to arms or a panacea?

**chem**

Write a partial decay series for Rn-220 undergoing the following sequential decays: á (alpha decay), á, â(beta decay), á. (Enter the mass number in the first raised box, the atomic number in the second lower box and the symbol of the element in the t...

**Math**

Im pretty sure you could use the pythagorean theorem a^2 + b^2 = c^2 just plug in the numbers you have and solve for c

**spanish**

Im not quite sure what your asking do you mean something like tus companeros de clase?

**math**

median=90 you find the median by putting all the numbers in order and finding the middle number

**math**

47 rounded to the ten's place is 50

**chemistry**

oops b and c should be b decay and in the directions its a,b,a,b

**chemistry**

Write a partial decay series for Po-214 undergoing the following sequential decays: á, â, á, â. Use e for an electron. Use the format +1 or -1 for charge. a)a decay b)â decay c)a decay d)â decay

**chem **

(b) If the natural abundance of Ag-107 is 51.84%, what is the natural abundance of Ag-109? 48.16 % (c) If the mass of Ag-107 is 106.905, what is the mass of Ag-109? 108.9 amu so i got the answers correct but kinda forgot how because it took me a while so do you think you could...

**11th grade**

sound travels at 350 m/s in warm air. "If you hear the echo in 10 seconds, how far away is the reflecting surface?

**science, density**

The density of sea water is slightly higher than that of fresh water. The higher density is due to the fact that sea water contains salts such as sodium chloride and magnesium chloride. Suppose you have a container that holds 5.00 kg of fresh water, which has a density of 1.00...

**Math**

how do I solve this problem. In 1920 the record for a certain race was 445.7 sec. In 1970, it was 44.2 sec. Let R(t) = the record in the race and t = the number of years since 1920. a) Find a linear function that fits the data R(t) = b) What is the predicted record for 2003? c...

**The Young Child and the Environment**

When a child not only throws a ball farther than she had previously, but also changes the way the throws the ball, the change is called A. Cumulative B. Multifactoral C. Quantitative D. Qualitative

**Chemistry**

A sample of gas occupies 3.00 L at 760 torr. Calculate the volume it will occupy at 1.45 atm and the same temperature?

**Chemistry**

A balloon filled with helium has a volume of 1.oo x 10^3 L at 20 degrees c. What will be the balloons volume at 30 degrees c, if the pressure surrounding the balloon remains constant?

**sport**

If air resistance is negligible what would the flight path of a shot from the moment of release to the moment immediately prior to landing look like using newtons 3rd law of motion?

**sport**

Can you name and explain 3 factors (excluding air effects ) which should be utilised by a shot putter to optimise the distance thrown using newtons trird law of motion

**Sport**

Why is the flight path of a shot putt different to that of a badminton shuttle using newtons third law of motion?

**sport**

How do i explain the effect of air resistance on the flight of two badminton shuttles, the first of which has been struck hard (with a greater application of force) and the second which has ben struck gently?

**Sport**

How do I explain using Newtons 3rd Law the nature of the reaction force which provides impulsion for a cyclist?

**Physics**

Bobpursley -- I do not understand. The answer was 5.7 s and I have no idea what equation was used to get that.

**Physics**

Can someone help me to understand how to work out this problem? The pilot of an airplane traveling 240 km/h wants to drop supplies to flood victims isolated on a patch of land 160 m below. The supplies should be dropped how many seconds before the plane is directly overhead?

**5th grade**

What is subject and verb of this sentence...The rest of story was never told.

**english**

What is the subject a d verb of this sentence...The rest of the story was never told.

**math**

Three different pairs of numbers that add together to get 1

**molal**

the freezing point of ethanol (C2H5OH) is -114.6C. the molal freezing point depression constant for ethanol is 2.00C/m. what is the freezing point (C) of a solution prepared by dissolving 50.0 g of glycerin (C3H8O3, A nonelectrolyte) in 200 g of ethanol. i tried to solve it on...

**molal (again)**

im not sure about the last step tho... i know the final answer is -120.0 but im not sure how to get to that...

**molal (again)**

i tried to solve it on my own but im confused about the last part, this i what i have so far.. moles of glycerin= 50.0/92.10=0.54 molality=0.54/0.200=2.7 is that right? im a little confused about the numbers im supposed to use for step 3... this was the question: the freezing ...

**Chemistry **

a car is traveling at a rate of 41.2 megameters/hr. what is the rate in cm/s?

**Physics**

An airplane flies 200 km due west from city A to city B and then 345 km in the direction of 32.0° north of west from city B to city C In straight-line distance, how far is city C from city A?

**8th grade math**

thanks

**8th grade math**

I need the equation for these numbers: 3, 9, 19, 33, 51 I see that the pattern goes up by 6, then 10, then 14, then 18 (4 more each time)

**molal**

Thank you for the help, i really appreciate it.

**molal**

the freezing point of ethanol (C2H5OH) is -114.6C. the molal freezing point depression constant for ethanol is 2.00C/m. what is the freezing point (C) of a solution prepared by dissolving 50.0 g of glycerin (C3H8O3, A nonelectrolyte) in 200 g of ethanol. any help would be appr...

**molal**

i tried to solve it on my own but im confused about the last part, this i what i have so far.. moles of glycerin= 50.0/92.10=0.54 molality=0.54/0.200=2.7 is that right? im a little confused about the numbers im supposed to use for step 3...

**molal**

thank you looks like i double posted... sorry

**molal**

the freezing point of ethanol (C2H5OH) is -114.6C. the molal freezing point depression constant for ethanol is 2.00C/m. what is the freezing point (C) of a solution prepared by dissolving 50.0 g of glycerin (C3H8O3, A nonelectrolyte) in 200 g of ethanol. any help would be appr...

**molal**

the freezing point of ethanol (C2H5OH) is -114.6C. the molal freezing point depression constant for ethanol is 2.00C/m. what is the freezing point (C) of a solution prepared by dissolving 50.0 g of glycerin (C3H8O3, A nonelectrolyte) in 200 g of ethanol. any help would be appr...

**college math**

Given the situation described, identify the type of sampling involved. A parish in Louisiana is divided geographically into school districts. A random sample from each of the school districts is selected

**english**

Their are three kids in the room.

**english**

Sentence Correction and Changes in Writing

**chemistry**

density of 8.48 g/cm3 volume of 114.5 cm3 of brass

**chemistry**

Common brass is a copper and zinc alloy containing 37.0% zinc by mass and having a density of 8.48 . A fitting composed of common brass has a total volume of 114.5 .How many atoms of copper does the fitting contain?

**MATHS----Matrix**

For a given square matrix A the predicted values of matrix B are: predicted B=A(A'A)^(-1)A'B why is the matrix C=A(A'A)^(-1)A' an idempotent and symmetric matrix? and is this matrix invertible?

**math**

Simplify. Your answer should contain only positive exponents. (when a number is between *__* its an exponent) 5y*-5* - ------- -u*5* v*-4* .(times) -uv*5* sorry if this is a bit confusing (hard to write this on a computer)

**Statistics**

20 percent of the interval

**Statistics**

20 percent of the interval

**Physics**

The diameter of some celestial body is 3080 km. What is the volume of this body? _____m3 How many of these celestial bodies would be needed to create a volume equal to that of Earth? The radius of the Earth is 6.38 106 m.

**physics**

The diameter of some celestial body is 3080 km. What is the volume of this body? _____m3 How many of these celestial bodies would be needed to create a volume equal to that of Earth? The radius of the Earth is 6.38 106 m.

**eth/125**

·Write a 700- to 1,050-word essay in which you answer the following questions: Conduct research to determine if the ethnic group colonized or if it immigrated to the United States. What country did they originate from and why did they enter the U. S.? Did the group face...

**physics**

A charge of -3.35 nC and a charge of -7.00 nC are separated by a distance of 40.0 cm. Find the position at which a third charge of +7.10 nC can be placed so that the net electrostatic force on it is zero.

**math**

If a vehicle gets 16 MPG and gas costs $2.70/gallon. How much would it cost to drive the vehicle 30 miles? Can someone help me find a formula to figure this out?

**psychology**

I was asked to define independant and dependant variables without defing, but buy using an example...would this be one...two digging dogs, one never corrected for digging(IV) and one corrected by a loud noise(DV), or would that be classical conditioning?

**4th grade**

Independent and dependent variables are related to one another. The Independent part is what you, the experimenter, changes or enacts in order to do your experiment. The dependent variable is what changes when the independent variable changes - the dependent variable depends ...

**earth science**

how do members of the biosphere affect the geosphere?

**Human service**

When is it inappropriate to share a hunch?

**us history**

compare nixion's policies of engagement with foreign policy strategies used during the cold war

**statistics**

The mean weekly earnings of all male workers in a state is $775 and the mean weekly earnings of all female workers in the same state is $658. Suppose we select one sample of 400 male workers and another sample of 300 female workers from this state. What is the mean of the samp...

**Paine College**

okay, any step in the right direction would help

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