Tuesday

September 1, 2015
Total # Posts: 390

**chemistry**

Write the formulas of the compound NH4+ formed by specified cations with the following anions:OH-, NO3-, CO3-2,HSO4-, PO4-3 . Use the given order of anions
*September 27, 2012*

**chemistry**

The half-life for the radioactive decay of calcium-47 is 4.5 days.If a sample has an activity of 4.00uCi after 13.5 days, what was the initial activity of the sample?
*September 26, 2012*

**chemistry**

Technetium-99m is an ideal radioisotope for scanning organs because it has a half-life of 6.0 {\rm hr} and is a pure gamma emitter. Suppose that 280{\rm mg} were prepared in the technetium generator this morning. How many milligrams would remain after the following intervals?
*September 26, 2012*

**chemistry**

Iodine-131, a beta emitter, has a half-life of 8 days.How many grams of a 10.0g sample of iodine-131 would remain after 56.0 days?
*September 26, 2012*

**chemistry**

When californium-249 is bombarded by oxygen-18, a new isotope and four neutrons are produced. Express your answer as a nuclear equation.
*September 26, 2012*

**chemistry**

Radon-222 undergoes alpha decay.what is the nuclear equation
*September 26, 2012*

**chemistry**

Technetium-99m is an ideal radioisotope for scanning organs because it has a half-life of 6.0 {\rm hr} and is a pure gamma emitter. Suppose that 280{\rm mg} were prepared in the technetium generator this morning. How many milligrams would remain after the following intervals?
*September 26, 2012*

**chemistry**

Technetium-99m is an ideal radioisotope for scanning organs because it has a half-life of 6.0 {\rm hr} and is a pure gamma emitter. Suppose that 280{\rm mg} were prepared in the technetium generator this morning. How many milligrams would remain after the following intervals?
*September 26, 2012*

**math**

As an entrepreneur, there are going to be many decisions that you need to make, such as the price to charge your customers for your goods and services. You have just graduated from college and recently opened a specialty pizza restaurant. Based on surveys conducted in your ...
*September 25, 2012*

**chemistry**

thanks a lot big help
*September 24, 2012*

**chemistry**

The safe level of radon gas at home is 4X10e-12 Ci/L or less. If you measure radon levels in the basement what is the maximum number of Ci that could be safe to find in a basement with dimensions of 12 ft x 15 ft x 6 ft?
*September 24, 2012*

**chemistry**

It takes 1 hour and 17 min. for a 1.000g sample of a certain isotope to decay to 0.121g. What is the half-life of this isotope? plssss helpp
*September 24, 2012*

**chemistry**

if you are exposed to all sources of radiation from natural sources and human activities (worldwide average). How many years would it take for you to absorb a fatal dose of radiation plss help
*September 24, 2012*

**Science chemistry**

It takes 1 hour and 17 min. for a 1.000gsample of a certain isotope to decay to 0.121g. What is the half-life of this isotope? plssss helpp
*September 24, 2012*

**chemistry, i need help like a.s.a.p!!!!**

Volume= 3.1 x 4.6 x 1.9 = 27.094cm3 Density=mass/volume = 19.07g / 27.094 cm3 Density= 0.7038g/cm3 or 0.704g/cm3
*September 24, 2012*

**Chemistry**

Carbon-14 has a half-life of 5730 years In a plant fossil you find that the 14 C has decayed to 1/8 of the original amount how long ago was this plant
*September 24, 2012*

**Physics**

A person walks 13.9◦ north of east for 2.51 km. Another person walks due north, then due east to arrive at the same location. How far due north would this person walk? How far due east would this person walk?
*September 16, 2012*

**Physics**

A person walks 13.9◦ north of east for 2.51 km. Another person walks due north, then due east to arrive at the same location. How far due north would this person walk? How far due east would this person walk?
*September 16, 2012*

**math**

add or subtract the following polynomials as indicated (5.9x3 + 3.4x2 -7)-(2.9x3-9.6x2 +3)
*September 4, 2012*

**math**

tracy had coffee once a day, and the special blend she bought at Donna's Coffee Stop cost about $3.00 a cup. Max bought coffee at Donna's coffee stop twice a day. He bought several different types of special blends that cost $.400 a cup on average 3. Tracy and Max ...
*August 30, 2012*

**Math**

Find the remainder when 13^18 + 19^12 is divided by 247.
*August 2, 2012*

**Math**

what does x reduce to???? 6x=15(mod 21) 2x=5(mod 7) x= ?(mod)7
*August 2, 2012*

**Math**

What are the 3 solutions? I'm stuck! 6x=15(mod 21) a=6,m=21,b=15 d=gcd(6,21)=3 solns. 6x=15(mod 21) 2x=5(mod 7) 21=6(3)+3 6+3(2)+0 0=6-6 6-(21-6(3))=3 6-21+18=3 6( )-21()=3 (21-6(3))(15)-6=3 ???????
*August 2, 2012*

**Math**

Find the units digit in 23^7777 by looking for mod 10.
*August 2, 2012*

**Math**

Consider the congruence 6x=15(mod 21). How many solutions does the congruence have? What are all the solutions?
*August 2, 2012*

**math**

Round all answers to the nearest hundredth square root of b^2-4ac;b=3,a=-1,c=-2?
*July 27, 2012*

**math **

Round all answers to the nearest hundredth -5a^2;a=-2?
*July 27, 2012*

**world mythology**

What are the implied moral values of the Greek/roman underworld?
*July 6, 2012*

**world mythology**

What are the cultural assumptions of the greek/roman underworld?
*July 6, 2012*

**world mythology**

Identify the main characteristics of the Greek/roman underworld
*July 6, 2012*

**math116**

in some year election for the president there were 86.7 million voters,whereas in the next year there were 126.2 million voters. find the percent change in the number of voters.
*June 27, 2012*

**english language writing skills**

after a prolonged delay due to technical difficulties,the program resumed. identify the verb.
*June 1, 2012*

**English/Literature**

List the six people presented in this excerpt from Hiroshima. Besides surviving the explosion of the atomic bomb, what do they have in common?
*May 15, 2012*

**math**

Solve the equation: 6x^2+12x+5=0
*May 5, 2012*

**Geometry**

The ratio of the areas of two similar trapezoids is 1/9. What is th eratio of the lengths of their altitudes?
*May 2, 2012*

**math, trig**

Graph one period of the following function. Show all work . y=2sinx+2cosx
*April 18, 2012*

**mth, trig**

Thanks but how did you find that? My numbers came out completely different -_-
*April 18, 2012*

**mth, trig**

Given cos a=-7/25 in quadrant II , and sin b=-12/13, in quadrant IV , find cos(a+b) and sin2a
*April 18, 2012*

**Math**

Thank you soooo much!
*April 8, 2012*

**Math**

Damien sets up a bucket to catch rain drops the bucket can hold 1 gallon. If each raindrop is mae of about 1/90 fluid ounce of water,how many raindrops will the bucket be able to hold?
*April 8, 2012*

**College Chemistry**

3.1
*March 26, 2012*

**math**

There are 12 inches in a foot and 36 inches in a yard, so if your are trying to find how many in a yard: 36 * 12 =
*March 1, 2012*

**geometry**

point A is located at (1,5) and point B is located at (3,2). What is the length of line segment AB in simplest radical form
*February 15, 2012*

**CHEMISTRY**

What happens to the NH4+ and Cl] ions when they enter the water? Does this process release or require energy?
*February 9, 2012*

**CHEMISTRY**

What happens to the NH4+ and Cl] ions when they enter the water
*February 9, 2012*

**math**

If anyone could answer this it would help me so much. (-36)(-5/-9) - (-20) = What do I do if there are two numbers with parentheses?
*February 9, 2012*

**math**

Thank you
*February 9, 2012*

**math**

What is -16 + -8 x -2 -(4-9)= ? I did it and got -72. I want to know if I'm right. I'm so confused with operations. Would you subtract the numbers and add, then multiply?
*February 9, 2012*

**math**

I knew it! Thanks
*February 8, 2012*

**math**

what is -3 x -3 x -3 x -3? My mom and I were having a debate and I think it's 81, but she thinks it -81. Which one of us is right?
*February 8, 2012*

**3 grade math**

They both intersect. Perpendicular lines intersect to form right angles, while intersecting lines just intersect. A right angle is 90 dergees. Any angle less than that is an acute angle. Any more is an obtuse angle and a straight line is 180›.
*February 8, 2012*

**cell crossword puzzle 14 across**

Golgi Complex
*February 1, 2012*

**Math**

It forms a triangle. I don't know what kind since I can't see the picture or angles.
*January 30, 2012*

**physics**

A tennis ball is thrown vertically upward with an initial velocity of +7.5 m/s. What will the ball’s velocity be when it returns to its starting point? The acceleration of gravity is 9.81 m/s 2 . Answer in units of m/s How long will the ball take to reach its starting ...
*January 29, 2012*

**physics**

A ﬂowerpot falls from a window sill 25.3 m above the sidewalk. What is the velocity of the ﬂowerpot when it strikes the ground? The acceleration of gravity is 9.81 m/s 2 . Answer in units of m/s How much time does a passerby on the sidewalk below have to move out...
*January 29, 2012*

**math**

Monday is 4 hours.
*January 18, 2012*

**Math**

1/4 times 5 = 1/4 * 5/1 = 5/4, The improper fraction. The mixed number is 1 1/4.
*January 17, 2012*

**math**

Assuming that the large shirts are the adult shirts, then the person has a 5 out of 12 chance of getting one.
*January 17, 2012*

**Math; I really need help.**

The standard form would be x + y = -5. But, I am not sure if that is the same for multiplication.
*January 17, 2012*

**Math**

There are an abundance of answers for this question. I can tell you of one such as 6,000 + 7,000 + 4,491 because this is one of the easiest.
*January 12, 2012*

**Science 7R**

Unless that 79 is a 79.5 or higher than it is not good for an 80.
*January 12, 2012*

**geometry**

You forgot to give us the lenght of the side of the line that connects from the middle of the pentagon to a side of the pentagon.
*January 12, 2012*

**algebra**

If w = weeks, I would use the equation: $20 + 6w = $150 - $4w. You can than solve this by finding w.
*January 10, 2012*

**thunderstorms**

Thanks!
*December 4, 2011*

**Thunderstorms**

Can you suffer from memory-loss if you get hit by a lightning bolt?
*December 4, 2011*

**English**

Using the lists of possible answers, use the letters assigned to the characters/people to identify who would be the speaker of each of the following paraphrases/quotations: 1)I think we'll all be destroyed by the A-Bomb,so why should I care about anything? 2)We were dared ...
*December 3, 2011*

**English**

Which of these is the properly punctuated sentence? a)Ted went to work and Bob went home. b)Ted went to work; and Bob went home. c)Ted went to work. And Bob went home d)Ted went to work, and Bob went home. Would the correct answer be D?
*December 3, 2011*

**English**

supposed? The answer is A.
*December 3, 2011*

**English**

I think the answer is B
*December 3, 2011*

**English**

Which of the following is correct? a) We were supposed to go to the game today, but it rained. b)We were suppose to go to the game today, but it rained.
*December 3, 2011*

**English**

Which of the following is correct? a)Who's toothbrush is floating in the toilet? b)Whose going to Dairy Queen with me? c)Whose jacket is that? d)b&c I believe the answer is C
*December 3, 2011*

**English**

which of the following is an example of a fragment? A) When Ted went to work, Bob went home. B) Although Ted went to work and Bob went home. C) Bob went to work although Ted went to work. D) Although Ted went to work, Bob went home. I Think the answer is B.
*December 3, 2011*

**Aztecs**

could someone tell me more about the Aztecs. (Yes, I have checked google and I have some information). -Thanks, w/apprecation Shay
*November 30, 2011*

**African American History**

What European nations were the first to engage in trade talks with Africans
*November 15, 2011*

**algebra**

30/x+20/x-20=1
*October 30, 2011*

**math 11 grade**

How do you do this 5a+(9)-12e*5a+(3)
*September 26, 2011*

**Physics**

a car leaves skid marks 84 m long on the highway. Assuming a deceleration of 7.50 m/s2, estimate the speed of the car just before braking.
*September 19, 2011*

**Math**

Find how much money there will be in the account after the given number of years. Principle $8500 Rate 4% Coumpounded quarterly Time 4 yeats A=8500(1+.04/4)raised to 40th power A=8500(1.01)raised to 40th power I am stuck here, how do you raise to the 40th power
*August 27, 2011*

**Math**

Use division to convert the base ten numeral 35 to base five.
*August 24, 2011*

**algebra**

Express in terms p. 2 square root of -36
*August 1, 2011*

**algebra**

multiply. 3x+3 by -4x^2+4x-2
*August 1, 2011*

**math**

How do you find the nth term in a sequence of numbers if the values are increasing then decreasing? Ex. 1: -2, 3: 10, 5: -18
*July 27, 2011*

**algebra**

The length of a rectangle is 2 meters more than its width. If the area is 35 square meters, what are the length and width?
*July 26, 2011*

**algebra**

factor the following expression into a product of two binomials. 64x^2-64x+16
*July 26, 2011*

**algebra**

completely factor the following expression. 16a^2-40ab+25b^2
*July 26, 2011*

**algebra**

use the "difference of squares" rule to factor the following expression. 64z^4-81a^4
*July 26, 2011*

**intermediate algebra**

factor the following expression completely: 70w^3-125w^2+30w
*July 25, 2011*

**intermediate algebra**

factor completely. Remember to look first for a common factor. If a polynomial is prime, state this. -4t^2+64 -(4t^2-64 =((2t)^2-8^2) (a^2-b^2)=(a+b)(a-b)
*July 25, 2011*

**algebra**

can someone plz help me with these three problems(((( stressed out)))) I cannot figure these problems to save life so can someone throw me a lifsaver please!!!
*July 21, 2011*

**algebra**

Short answer. Find the quotient: 6x^3-x^2-7x-9 ------------- 2x+3
*July 21, 2011*

**algebra**

plz help me
*July 21, 2011*

**algebra**

please get into more detail more for me to understand Algebra is one my weakest subjects
*July 21, 2011*

**algebra**

Essay. Show all work. Find the quotient. 49a^2-b^2 --------- 7a-b
*July 21, 2011*

**algebra**

Essay. Show all work. Find the quotient y^4+3y-1 -------- y^2-3
*July 21, 2011*

**algebra**

Essay. Show all work. A school designer wants to create a whiteboard with the optimal dimensions to enhance learning. it is determined that if one side of the whiteboard is x+y inches, the other side should be x^2+6xy-4y^2 inches. Write an algebraic expression for the area of ...
*July 19, 2011*

**algebra**

Essay. Show all work. Find the following product.(x^2-2)(x^3-4x+9)
*July 19, 2011*

**algebra**

Essay. Show all work. the rectangular swimming pool is given by 2x^2-5x-3 ft.^2. One side length of the pool is given by 2x+1 feet. What is an algebraic expression for the other side length of the pool? Simplify this, and include correct units as part of your answer.
*July 19, 2011*

**algebra**

Essay. Show all work. A gardener wants to create a triangular garden in the shape of a right triangle with the shortest side length x-3y ft. and the middle length side x+6y ft. What ia an algebraic expression for the area of the garden? be sure to multiply this out and express...
*July 19, 2011*

**algebra**

Essay, show all work. find the following product. (y-8)^2
*July 19, 2011*

**algebra**

please someone help me
*July 18, 2011*