# Posts by kara

Total # Posts: 458

MATH
Simplify completely: -3(4-9)+6-2(-8+5)

algebra 2
do elephants wear roller skates?

physics
for a)you must first calculate the angular frequency,w, you are only given the frequency,f. to do that you use the equation: w=2*pi*f =2*pi*3Hz next you take that and put it into the equation with k being the spring constant,w being the angular velocity, and m being the mass: ...

chemistry
classify the compound as having ionic, polar covalent, or pure covalent bonds. Sb2P5 I know that a metal and nonmetal form an ionic bond, and two nonmetals form covalent bonds. The trouble I am having is that Sb is a metalliod and when it forms with a non-metal, what kind of ...

Chem!
How much energy does the electron have initially in the n=4 excited state? Enter your answer numerically in joules.

CHEM!
A radio station's channel, such as 100.7 FM or 92.3 FM, is actually its frequency in megahertz (MHz), where 1MHz=10^6Hz. Calculate the broadcast wavelength of the radio station 98.30 FM.

CHEM
I got C2H4?

CHEM
To identify a diatomic gas (X_2), a researcher carried out the following experiment: She weighed an empty 1.00-L bulb, then filled it with the gas at 1.10atm and 23.0 degrees celsius and weighed it again. The difference in mass was 1.27g . Identify the gas. Express your answer...

CHEM
To identify a diatomic gas (), a researcher carried out the following experiment: She weighed an empty 1.00- bulb, then filled it with the gas at 1.10 and 23.0 and weighed it again. The difference in mass was 1.27 . Identify the gas. Express your answer as a chemical formula.

CHEM

CHEM
To identify a diatomic gas (), a researcher carried out the following experiment: She weighed an empty 1.00- bulb, then filled it with the gas at 1.10 and 23.0 and weighed it again. The difference in mass was 1.27 . Identify the gas.

CHEM
Calculate the density of oxygen, , under each of the following conditions: STP 1.00atm and 25.0 degrees celsius Express your answers numerically in grams per liter. Enter the density at STP first and separate your answers by a comma.

CHEM
A cylinder with a movable piston contains 2.00 of helium, , at room temperature. More helium was added to the cylinder and the volume was adjusted so that the gas pressure remained the same. How many grams of helium were added to the cylinder if the volume was changed from 2....

Social Studies 30
Did the USA enhance the ideals of the League of Nations between 1920 and 1933?

Math
How do I find the area of the region bounded by the curves y = e^x, y = e^-x, x= -2, and x = 1? Even if you could just help me in getting started it would be a HUGE help. Thanks!

I need a little help on math. It has to do with kilograms and weight.

algebra ll
the system of equations y=2x - 3 and y=4 x -3 has: here are the mutiple choices :exactly one solution, no solution, infinitely many solutions , exactly two solutions which one is it and choose the description of the system of equations x plus 2y=7 and 3x - 2y=5 the mutiple ...

algebra ll
To solve the system of equations, which expression could be substituted for x into the first equation? 3x-5y=14 x+4y=10 a)10-4y b)4y+10 c)(1/4)x+(5/2) d)(-1/4)x+(5/2)

science
what is an organism that feeds off of other living or dead organisms?

Physics
If the electron in a hydrogen atom obeyed classical mechanics instead of quantum mechanics, would it emit a continuous spectrum or a line spectrum?

Physics
When an electron makes a transition from its first quantum level to ground level, the energy difference is carried by the emitted photon. In comparison, how much energy is needed to return an electron at ground level to the first quantumlevel?

Physics
Uranium-238 is 238 times more massive than hydrogen. Why, then, isn't the diameter of the uranium atom 238 times that of the hydrogen atom?

Physics
How does Rutherford's model of the atom account for the back-scattering of alpha particles directed at the gold foil?

Physics
Which color light is the result of a greater energy transition, red or blue?

1. Do you exercise or work out on a regular basis? no 2. Are you male or female? female 3. Do you smoke? no 4. How many carbonated soft drinks do you consume in a week. none 5. Do you drink coffee. occasionally 6. How many servings of fruit, or fruit juice do you consume in a ...

French
Well, my opinion isn't expert, but it sounds like a misprint. It should just be "des" both times because the particle "des" is of course "the" and should only apply to the plurality of the word "numbers"

Physics (Mechanics)
A uniform plate of height H= 0.69 m is cut in the form of a parabolic section. The lower boundary of the plate is defined by: y= 1.10x^2. The plate has a mass of 5.62 kg. Find the moment of inertia of the plate about the y-axis. Alright, I've done this so far: So I figured...

Physics
Alright, so what you are looking at is a conservation of energy problem. Total Mechanical Energy in a system where energy is conserved is always equal to the sum of the kinetic energy and the potential energy. The sum of the change in these two quantities is also equal to zero...

math
thank you

math
A rectangle has sides of 4x – 4 and 8x + 10. Find the expression that represents its perimeter

math
The sum of two numbers is 38. Their difference is 12. What are the two numbers?

Math
thank you so much

Math
The difference of two numbers(the second minus the first) is 48. The second is 8 less than 5 times the first. What are the two numbers?

The length of a rectangle is 8 in. more than twice its width. If the perimeter of the rectangle is 34 in., find the width of the rectangle.is it 1. 2 in. 2. 3 in. 3. 4 in. 4. 5 in.

math
can someone hep me please Population of Europe by Age Groups Population (in thousands) 1----------1950 --1970 --1995 Age 0-14--------143,175 166,367 139,464 Age15-64------- 359,162 421,432 487,110 Age 65+ 44,981- 68,642- 101,338 Age 75+ 14,553- 22,762- 38,139 Total--547,318 ...

math
can someone hep me please Use the following tabe to answer the question. Population of Europe by Age Groups Population (in thousands) 1----------1950 1970 1995 Age 0-14 143,175 166,367 139,464 Age15-64 359,162 421,432 487,110 Age 65+ 44,981 68,642 101,338 Age 75+ 14,553 22,762...

math
can someone hep me please Use the following tabe to answer the question. Population of Europe by Age Groups Population (in thousands) 1950 1970 1995 Age 0-14 143,175 166,367 139,464 Age15-64 359,162 421,432 487,110 Age 65+ 44,981 68,642 101,338 Age 75+ 14,553 22,762 38,139 ...

math
so it would be a and d

math
purple- 1 in 63 brown- 1 in 62

Algebra 1
explain: 3x-y=12 4x-5y=16 it is linear equations using substitution method

Algebra
Thank You, I am just making sure before I turn this in.

Algebra
Would this be correct? Factpr completley: y^3-12y^2+36y y(y^2-12y+36) y(y-6)^2

Algebra
I am wondering if I did this right? Write Using a positive exponets and simplify if possiable. (-3x)^2 I took the -3^2=9 over the x^2 and the answer would be - 9 over x^2

Algebra
I do not understand what I am supposed to do: The problems reads: Evaluate (assume x is not equal to 0). -10x^0 I did this though not sure about it, -10*x^0 -10*1 -10

algebra
I would say.... Mona, Jack, Pete, Nick

Algebra
Ohh, I knew something looked off...so it should be x^2-5x/80-9/20

Algebra
know I am supposed to use the FOIL method.But is this right? I am really not sure I did this right, something just seems off about it. So i would Multiply x/3 * 3x/4=x^2/4 x/3 *-3/5= -x/5 3/4 *3x/4=9x/4 3/4 * -3/5 I know to add both of my bottom numbers have to be the same so...

Algebra
How do you Multiply this? (x/3+3/4)(3x/4-3/5)

History
. Describe the three key concerns that Washington had for the future of the U.S. Explain how the country has progresses in each area and give one specific example. Here's an answer I posted for this question a few days ago. http://www.jiskha.com/display.cgi?id=1187480916

Chemical Kinetics
When experimentally determining the rate law, i am getting a negative fraction. is that right or am i doing something wrong? It is possibly right. I'd have to see you calculations to determine that. It would mean that the reaction is proceeding backwards.

science
Does salt water evaporate faster than fresh water? No. The reduction in vapor pressure and evaporaton rate is related to the fraction of the surface that is salt ions instead of water molecules. The Na+ and Cl- ions are not volatile.

Biochem
Can someone please help me find, or know of any molecules that are at least 20 bases (carbons, nitrogens..) long and have 3 hybrids (sp, sp2, dsp)

Probability
You throw a beanbag at a wall with 7 colored squares, each with an area of 1/4^2. If you hit a square, you win a prize. What is the probability of winning a prize? You need more information. For starters: 1) what is the total area of the wall? 2) Are landings on the wall ...

Social studies.. need help
What did the peolpe in Jamestown eat? Jamestown is where John Smith lived... Thankssss http://www.apva.org/exhibit/eats.html THANKSSSS!!!!!!!!!!!!!!!!!!!! LANCEEEEEEE!!!!!!!!!!!!!!

social studies

lane
Changes in size or shape occur what? This depends on what you are writing about. For doughnuts, changes in size or shape occur rarely, but for an expectant mom, they change daily. You'll need to be more specific in your question. It would also help if you put the SUBJECT (...