# Posts by kara

Total # Posts: 458

**Chemistry**

Thank you so much!

**Chemistry **

The photoelectric effect is a concern in space, where parts of a spacecraft exposed to the sunlight will develop a net positive charge, which can interfere with or damage sensitive cir The panels that cover the exterior of the Space Shuttle are composed of graphite fibers, ...

**Chemistry**

Yes it is "most common ion is: [Kr] 5s2 4d10 5p6". I have also spent quite a long time trying to figure this question out. The answer key said it's BaI2, which confused me more.

**Chemistry **

Element x has the highest first electron affinity in its period, the ground state electron configuration of its common is: [Kr] 5s2 4d10 5p6 Element Y is the second largest element in its period; its valence electron are in orbital(s) that have n= 6. What is the most stable ...

**Chemistry **

List SOF2, SO2F-, and S2O3^-2 in order of increasing sulfur-to-oxygen bond length. How do u tell by just looking at the Lewis structures?

**Chemistry**

I was able to figure it out, just forgot to simplify in the end.

**Chemistry **

A mineral that contains iron and sulfur has the cubic unit cell pictured below. What is the empirical formula for this mineral? •Fe atoms are the smaller spheres; one on each corner and one on each face of the unit cell •S atoms are the eight larger spheres; every S ...

**Chemistry **

Is the NO3- single bond length shorter than NO2H single bond length? Based on Lewis structure of it.

**Chemistry **

Howard Wolowitz is developing a radiation detector for the Intemational space Station. He uses a thin film composed of a metal alloy that has a threshold frequency of 5.5x10^15 Hz. When radiation is shone on the thin film, the fastest electron emitted has a velocity of 668000 ...

**Chemistry **

I have this question from an old exam for review. I tried the question but can't get the right answers. An electron in an electronically excited hydrogen atom undergoes a transition from a 6d to a 2p orbital, resulting in the emission of a photon. The photon strikes a ...

**Chemistry**

I figured out question A and B, now I am stuck at question C and D. The answers for question C is 3.52x10^-19 J and D is 1.35nm

**Chemistry **

I have this question from an old exam for review. I tried the question but can't get the right answers. An electron in an electronically excited hydrogen atom undergoes a transition from a 6d to a 2p orbital, resulting in the emission of a photon. The photon strikes a ...

**algebra **

A rope is cut into three and one-third is used. Then one-fourth of the remaining rope is cut off and used. The piece left is 6 meters long. How many meters long was the rope originally?

**Chemistry **

A farmer wants to capitalize on the amount of sunlight shining on his farm everyday by building a solar power tower. The manufacturer\'s specifications state that the solar tower has 5.0 × 101 heliostats, each with an area of 2.10 m2. If the total amount of solar ...

**Biology **

Which of the following mechanisms for osmoregulation or nitrogen removal is correctly paired with its corresponding animal? A) metanephridium-earthworm B) Malpighian tubule-?frog C) kidney-?insect D) flame- bulb?snake

**Biology **

Unikonta paraphyletic or monophyletic? Animalia paraphyletic or monophyletic?

**Chemistry**

a hydrogen atom in one of its excited states has an energy of -1.5129x10^-20 J

**Chemistry**

A hydrogen atom in one of its excited states ha an energy of -1.5129^20 J. What is the frequency of radiation is emitted when the atom relaxes down to its ground state?

**physics**

The displacement of a block of mass 778g attached to a spring whose spring constant is 38N/m is given by x=Asin(?t) where A=25cm. In the first complete cycle find the values of x and t at which the kinetic energy is equal to one half the potential energy. First position: First...

**p**

The displacement of a block of mass 778g778g attached to a spring whose spring constant is 38N/m38N/m is given by x=Asin(?t)x=Asin(?t) where A=25cmA=25cm . In the first complete cycle find the values of xx and tt at which the kinetic energy is equal to one half the potential ...

**physics**

A 300g particle oscillating in SHM travels 35cm between the two extreme points in its motion with an average speed of 30cm/s. Find: a) The angular frequency. b) The maximum force on the particle. b) The maximum speed.

**physics**

A 750g block is attached to a vertical spring whose stiffness constant is 1N/m . The block is released at the position where the spring is unextended. a) What is the maximum extension of the spring? How long does it take the block to reach the lowest point?

**physics**

A block attached to a spring is displaced from equilibrium to the position x=+0.5m and released. The period is 2.1s . At what positions and times during the first complete cycle do the following conditions occur. a) |v|=0.5vmax, Where vmax is the maximum speed? First position...

**physics**

With a block of mass m , the frequency of a block-spring system is 1.8Hz. When 50g is added, the frequency drops to 1Hz . Find m and the spring constant.

**physics**

The displacement of a block attached to a horizontal spring is given by x=0.5sin(7.8t?1.06)m What is the earliest time (t>0) at which x=0.16m? Find the acceleration when x=0.44m helppppppp

**Math**

How to rearrange the given equation for A: [ln(Ao/A)=k*t] * means multiply / means divide ln is the natural log function

**Math/Chemistry**

what about the ln? (natural log)

**Math/Chemistry**

How to rearrange the given equation for A: ln (Ao/A) = k*t

**Math/Chemistry**

No but what about the ln (natural log)?? the equation is [ln(Ao/A)=kt]

**Math/Chemistry**

How to rearrange the given equation for Ao: ln (Ao/A) = k*t

**Math**

keith went to the candy store and bought 2/6 of a pound of candy.8/10 of keiths candy was chocolate. how.many pounds of chocolate candy did keith buy?

**social studies**

summarize the reasons for writing the Declaration of Independence. Please help

**math 8th grade**

Thank you Ms.Sue

**math 8th grade**

How do you prepare for a math test?? Please help me i don't understand the question.

**TECH ED HELP**

1.A 2.A 3.C

**Math**

Please check my responses! ASAP Consider the following data set: 3,4,6,7,9,9,11 If 5 were added to each of the values, how would that affect the median? My Answer: The median would change and increase. Consider the following data set: 3,4,6,7,9,9,11 If 5 were added to each of ...

**Social Studies**

100% and btw GrimmGamer the pre test doesnt count as a game... but good luck

**Math Algebra**

A boat takes 1 hour less to go 200 miles downstream than upstream. If the rate of the current is 3 miles per hour, what is the rate of the boat in still water?

**Chemistry**

I've run into some difficulty with my chemistry homework. We went over this practise question in class today as an example. However, I wasn't able to fully grasp how to work it out. "How many grams of nitrogen form when 34.6 grams of nitrogen dioxide decomposes ...

**statistics**

A sign is posted in an elevator stating that the maximum number of people allowed is 25, and that the maximum weight capacity is 4000lbs. Suppose the distribution of the variable Weight (among the population using the elevator) is normal with mean 150lbs and standard deviation...

**English**

Yes, the first one.

**chemistry**

Are you on k12??

**Language Arts**

I need to write to compare and contrast geology and etymology. How do I do that?

**Algebra**

Then you Trisha much are on the side of the box of cereal states that there are 84 calories in a three fourths cup servings. How many calories are in eight cups of cereal? My question us how do i get started

**chemistry**

If I contain 3 moles of gas in a container with a volume of 60 liters and at temperature of 400 K, what is the pressure inside the container? Ideal Gas Law: PV=nRT I know I'm given the volume, temperature, and numbers of moles of gas, but how do I know which ideal gas ...

**Science**

A liquid solution of formaldehyde is 37% pure. This solution has a specific gravity of 1.037. The molecular weight of formaldehyde is 30.0. To 1.00 ml of this impure stock solution is added quantity sufficient total the total volume to 500 ml. If 1.00 ml of this solution is ...

**statistic**

12.5

**math**

280

**Math**

Joe wants to carpet a 12 foot by 18 foot rectangular living room and a square bedroom. One side length of the square bedroom is 12 feet. Carpet costs $3.50 per square foot. What percent of the total amount Joe will pay will be spent on carpeting the bedroom? Show your work ...

**math:order of operation**

TWO PART Ellen is playing a video game in which she captures butterflies. There are 3 butterflies onscreen, but the number of butterflies doubles every minute. After 4 minutes, she was able to capture 7 of the butterflies. A)LOOK FOR A PATTERN. Write an expression for the ...

**math**

3/7, 5/6, 4/5 least to greatest

**Medical Administrative Assistant**

I need help adding some stuff to this exam please help Exam 028005 It has come to my attention after a conversation with a DMD Medical Supplies representative that some of our work for them has been subpar. Knowing we are a customer driven company I did some investigation of ...

**chemistry**

can you please give me some practical applications of qualitative chem and quantitative chem...

**Chemistry**

.33333

**statistics**

Suppose x is a uniform random variable with c=10 and d=60. Find the probability that a randomly selected observation exceeds 30.

**Math**

The pressure exerted by a certain liquid at a given point varies directly as the depth of the point beneath the surface of the liquid. The pressure at 30 meters is 80 newtons per square centimeter. What pressure is exerted at 50 meters?

**math**

375(x)=2000 x=2000/375 x=5.33 So Tom can play 5.33 games you can also check this other way: 1game=375 tokens 6 games will be: 6x375=2250 Answer: Tom can't play 6 games!

**math**

how do you divide .29 by 34580

**Math**

What is .2 + .5674

**Chemistry**

A 9.00-L container holds a mixture of two gases at 43 °C. The partial pressures of gas A and gas B, respectively, are 0.257 atm and 0.579 atm. If 0.110 mol a third gas is added with no change in volume or temperature, what will the total pressure become?

**ASU**

How much MnO2(s) should be added to excess HCl(aq) to obtain 215 mL of Cl2(g) at 25 °C and 705 Torr?

**Chemistry**

The elements of which group in the periodic table release the most energy by gaining an electron? The elements of which group in the periodic table absorb the most energy when gaining an electron?

**english**

Questions about Avi(the author) Why was school a constant struggle for him? Avi kept writing because of the encouragement of his family and the help of whom? After college, what job did Avi take? where? When did Avi become interested in children's literature?

**grammar**

Is the word Drives transitive or intransitive in the following sentence? Michael drives every day.

**grammar**

is the word thirst transitive or intransitive in the following sentence? I thirst.

**grammar**

Is the verb drives transitive or intransitive in the following sentence? Micheal drives his own car.

**grammar**

Is the verb crave CRAVES in the following sentence transitive or intransitive? Fred craves cheeseburgers.

**algebra 1-2**

what is a natural number?

**grammar**

What part of speech is the word run in the following sentence? I have a run in my hose.

**math**

a family wants to build a pool their yard is 20 yards wide and thirty yards deep. unfortunately, the dealer only deals in liter size pools. what is the biggest size pool they can get?

**chemistry**

2NOBr(g) <==> 2NO(g) + Br2(g) and the value of Kc = 1.98, at a temperature of 282 K what is the value of Kp ? (Hint: Use the value of R in the appropriate units.)

**Physics**

An electron with a horizontal speed of 4.0 * 10^6 m/s and no vertical component of velocity passes through two horizontal parallel plates. The magnitude of the electric field between the plates is 150 n/c the plates are 6.0 long A) calculate the vertical component of the ...

**Physics**

An electron with a horizontal speed of 4.0 * 10^6 m/s an no vertical component of velocity passes through two horizontal plates. The magnitude of the electric field between the plates is 150 n/c. The

**Sciene**

yeah

**Sciene**

How do living things get rid of cellular waste?

**Algebra**

A dog trainer has 64 ft of fencing that will be used to create a rectangular work area for dogs. If the trainer wants to enclose an area of 192 ft2, what will be the dimensions of the work area?

**Geometry**

Given: Segment CE bisects <BCD; <A is congruent to <B Prove: Segment CE ll to segment AB -I used the exterior angle theorem to set the four angles equal to each other, but i don't know how to move on from there. The converse of something (maybe alternate interior ...

**Algebra**

2x/3 + 1/4= x/6 - 1/2 solve for x

**Algebra**

3/4 ÷ x = 1/3 solve for x

**math**

Thanks for the pointer Steve! I'll try that :)

**math**

2a + 7b + 17c = 31 How do you work out what a,b and c are?? any help would be appriciated

**physics**

Your friend weighs 145 lb. What is her mass in kilograms if she went to the moon where the acceleration of gravity is 1/6 that on earth? i know that her weight in newtons is 652.5, and that her mass in kilograms is 65.25, and that her weight in newtons if she went to the moon ...

**math**

Two blocks sit on a horizontal surface. They are connected to each other by a massless cord. The block on the left has a mass of 5.1 kg and the block on the right has a mass of 3.0 kg. Another massless cord is attached to the block on the right and pulls that block with a ...

**math**

A skydiver with a weight of 185 lbs is falling. At a certain moment the force of air resistance on the sky diver is 145 lbs. What is the skydiver's acceleration at this moment? (Hint: Remember that the weight of an object is given by mg.) AND When the skydiver reaches a ...

**art history**

write me an essay over Imagine that you are a prehistoric artist and write a 350 to 500 word story explaining why you are an artist and what the purpose of your art is. Be clear about what time period and location you are from. You may do research about prehistoric art, but be...

**science**

What is the cell potential and voltage gradient?

**physics**

An object has a height of 65 cm and is positioned 6.2 m in front of a spherical mirror. Its image distance is 1.9 m. Calculate the height (including its sign) of the image in centimeters.

**Calculus**

699

**Pre Cal**

Two tracking stations are on the equator 158 miles apart. A weather balloon is located on a bearing of N 41degrees E from the western station and on a bearing of N 21degrees E from the eastern station. How far is the balloon from the western station.

**Pre Cal**

An airplane leaves an airport and flies due west 150 miles and then 230 miles in the direction S 39.67 degrees W. How far is the plane from the airport at this time to the nearest mile.

**Pre Cal**

tan 2x- tan 6y/ 1+ tan 2x tan 6y

**Pre Cal**

cos 75 deg

**Physics**

AM radio signals are broadcast at frequencies between 540 kHz and 1585 kHz (kilohertz) and travel 3.0 X 10^8 m/s. a. What is the range of the wavelengths for the signals? (from shortest to longest). b. FM frequencies range between 88MHz and 108 MHz (megahertz) and travel at ...

**physics**

The speed of sound in water is 1498 m/s. A sonar signal is sent straight down from a ship at a point just below the water surface, and 1.95 s later, the reflected signal is detected. How deep is the water?

**physics**

The speed of sound in water is 1498 m/s. A sonar signal is sent straight down from a ship at a point just below the water surface, and 1.95 s later, the reflected signal is detected. How deep is the water?

**Calc**

pi* integral from 0 to sqrt(8) A(x)=(8y)^2 dy -(y^3)^2 dy

**calculus**

Find the volume of the solid S that satisfies the two following conditions. First, the base of S is the elliptical region with boundary curve 9 x2 + 4 y2 = 36, and second, the cross-sections of S perpendicular to the x-axis are isosceles right triangles with hypotenuse in the ...

**physics**

how do scientist know that the chemical elements here on earth are the same as on the planets in space and not some different elements

**Astronomy**

Later this year Venus will transit the Sun. Use the known diameter and distance of the Sun and Venus to determine how big the Sun will appear to be in degrees and how big Venus will be in degrees during the transit.

**math**

Norman received $60 for working 8 hours. At this rate, how much would receive for working 35 hours?