Science & Mathematics - 18 November 2007

2007-11-18 10:51:35 · 8 answers · asked by haru 2 in Mathematics

Use the information to determine if the pair of elements are isotopes or different elements.

1. Element D has 6 protons and 7 neutrons.
Element F has 7 protons and 7 neutrons.

2. Element J has 27 protons and 32 neutrons.
Element L has 27 protons and 33 neutrons.

3. Element X has 17 protons and 18 neutrons.
Element Y has 18 protons and 17 neutrons.

4. Element Q has 56 protons and 81 neurtons.
Element R has 56 protons and 82 neutrons.

5. Element T has an atomic nu,ber or 20 and an atomic mass of 40.
Element Z has an atomic number of 20 and an atomic mas of 41.

6. Element W has 8 protons and 8 neutrons.
Element V has 7 protons and 8 neutrons.

How can you tell which is which? I am really confused. I don't know how to tell if it is an isotope or a different element. Please help!?

2007-11-18 10:51:27 · 4 answers · asked by Emily 2 in Chemistry

Write a word equation for:
a) A gas causes a glowing splint to burst into flames reacts with sugar to produce water and gas that turns limewater milky.

b) Sodium metal reacts with water to produce sodium hydroxide and a gas that reacts explosively to a blazing splint.

c) Natural gas(mathane)burns in oxygen to produce one product that turns limewater milky, and a second product with fixed points of 0 degrees Celsius and 100 degrees Celsius.

2007-11-18 10:49:56 · 1 answers · asked by Zayka 1 in Chemistry

Thanks in advance!

2007-11-18 10:47:37 · 1 answers · asked by big zach!!!! 2 in Physics

Suppose the 2/5 life of a chemical compound is 873 years.

a) How much (what fraction) remains after 271,390 years.
b)when will 1/500 of the original amount remain?

I don't want the answers I want to do the work myself but i have no clue where to start. Please help.

2007-11-18 10:46:39 · 2 answers · asked by Anonymous in Mathematics

hope you can understand this
24√(1-m)+10=6

radical is only over the 1-m and it is 2 to the 4th radical

Can you show me step by step so I can understand

2007-11-18 10:45:33 · 1 answers · asked by angelsurvivor04 1 in Mathematics

k^2+2k-3

do i plug in -3 or 0 since they dont give me a binomial?

2007-11-18 10:45:30 · 4 answers · asked by Ballerina 5 in Mathematics

Can I have the complete history of the atomic number 23 which is Vanadium?

2007-11-18 10:45:19 · 2 answers · asked by ~Katie~ 2 in Chemistry

a^5 / a^8 The answer cannot have a negative exponent. Please explain how you got your answer.

2007-11-18 10:43:06 · 5 answers · asked by Anonymous in Mathematics

What is the formula for this?

Solve by using the quadratic formula. Express your answer in simplified radical form
x^2=3x+1

2007-11-18 10:42:30 · 1 answers · asked by meme 1 in Mathematics

I was asked 2 questions in my math homework (i did everythign but these 2. I dont understand them. ANd I dont know how to do them. This is an online class) So help me please (understand and solve)

1. An example of an INTEGER that is
a)a perfect square between 30 and 40 inclusive is ________
b)the SUM OF ALL non-perfect squares between 5 and 10 exclusive are_____
(all answer are numerical)

2. The distance between the two points (4,-2) and (-4, 13) to the nearest integer is ______
(again it is numerical)

Please help! Thank you sooooo much everyone! You are amazing!

2007-11-18 10:41:18 · 5 answers · asked by matthew_edward34 1 in Mathematics

Zn(s) + Cu2+(aq) Zn2+(aq) +Cu(s)
Under standard conditions, what is the maximum electrical work, in kilojoules, that the cell can accomplish if 40.9 g of copper are plated out?

2007-11-18 10:40:26 · 1 answers · asked by softshimmer 2 in Chemistry

hope you can understand this
24√(1-m)+10=6

radical is only over the 1-m and it is 2 to the 4th radical

2007-11-18 10:37:51 · 2 answers · asked by angelsurvivor04 1 in Mathematics

solve the equation
the 4's are little and a bit below. sry i dont kno how to say it.

2007-11-18 10:37:23 · 4 answers · asked by dave h 1 in Mathematics

2007-11-18 10:36:06 · 4 answers · asked by Dwill 1 in Chemistry

A cylinder with a 16-cm-diameter piston contains gas at a pressure of 3.0 atm.
Part A
How much force does the gas exert on the piston?
Part B
How much force does the environment exert on the piston?
Part C
The gas expands at constant pressure and pushes the piston out 10 cm. How much work is done by the environment?
Part D
How much work is done by the gas?

2007-11-18 10:34:38 · 1 answers · asked by Anonymous in Physics

should i bother setting my alarm for school tomorrow because its snowing now or shall i set it and listen to the radio to check whether my school will be open?

2007-11-18 10:34:16 · 25 answers · asked by ♥ [JPA] ♥ MissSnape ♥ [ART] ♥ 3 in Weather

i need help deciding which brand telescope to get i already know the type its a 10" dobsonian Newtonian reflector i'm not sure what brand to get celestron, meade, zhumell, or orion if anyone has any experience with these brands and types of telescopes please help me out!

2007-11-18 10:31:38 · 5 answers · asked by th3_ch0s3n_0n3 2 in Astronomy & Space

Xsquared + 15x +36 = 0

(Sorry for putting squared, I couldn't put the little 2 without it looking misleading!)

Please could you explain to me how to do it also? Thanks!! x

2007-11-18 10:30:23 · 12 answers · asked by Anonymous in Mathematics

a^x = x^b
find all possible x.
I can't find anyway to solve this equation,
is this equation not algebraically independent?
how can I find the result of this equation without a calculator?

2007-11-18 10:29:08 · 3 answers · asked by Mgccl 1 in Mathematics

solve the equation
the 4's are little and a bit below. sry i dont kno how to say it.

2007-11-18 10:29:00 · 2 answers · asked by dave h 1 in Mathematics

The intensity of sunlight that reaches the Earth's atmosphere is about 1500 W/m2. What is the intensity of the sunlight that reaches Jupiter? Jupiter is 5.3 times as far from the sun as Earth. [Hint: Treat the Sun as an isotropic source of light waves.]

W/m2

2007-11-18 10:28:38 · 3 answers · asked by sportzblock 1 in Physics

I'm getting a B.S. in computer science this summer and I'm thinking of doing something else for my master's. I'm considering engineering because I'm strong in math and science and I want to have a challenging but steady job, but I worry because I've never considered myself to have an "engineer's personality" (I didn't really take things apart as a kid or play with constructor sets, etc.). I do like computer programming very much - it's like solving logic puzzles! - but I'm thinking to branch out and do something really interesting and difficult.

Are there any engineers or engineering students out there, especially woman engineers, who can tell me how they came to choose engineering and what their personality is like? I'm trying to find out if I'll be a good engineer, and what type is right for me.

2007-11-18 10:27:54 · 6 answers · asked by Lisa 3 in Engineering

2007-11-18 10:26:06 · 4 answers · asked by Lorena G 1 in Geography

This is a question on a chemistry lab that I recently did and I don't understand it at all! Please give me some help!!!!

It is possible to get a false-positive or a false-negative result when testing for ion? Propose a situation that could lead to a false-positive for a particular ion. Choose a different ion and show how a false negative could result. Which do you think is more likely to happen, a false positive or a false neagative result? Explain your reasoning.

2007-11-18 10:25:24 · 1 answers · asked by ♥PaIgE♥ 3 in Chemistry

A water balloon is catapulted into the air from the top of a building. The height h(t), in meters, of a balloon after t seconds is h(t) = -5t(exponent 2) + 30t + 10. When will the balloon reach a height of 30m?

h(t) = 30
30 = -5t(exponent 2) + 30t + 10
30 = -5(t(exponent 2) - 6t -2)
I'm stuck here.
normally we'd find two numbers that add to the middle number (-6) and multiply to the last number (-2).
Help pleaseeeeee?

2007-11-18 10:24:52 · 5 answers · asked by Bo 3 in Mathematics

A voltaic cell is based on the following reaction.
Sn(s) + I2(s) Sn2+(aq) + 2 I-(aq)
Under standard conditions, what is the maximum electrical work, in joules, that the cell can accomplish if 81.5 g of Sn is consumed?

2007-11-18 10:24:02 · 1 answers · asked by softshimmer 2 in Chemistry

2007-11-18 10:21:37 · 11 answers · asked by bthat 1 in Physics

In right traingle ABC, m
It was on a practice test and I completely guessed and got it right...answer=17. Can someone explain how to get this?

2007-11-18 10:21:12 · 5 answers · asked by Racccchel. 4 in Mathematics

Thank you show work

2007-11-18 10:20:27 · 6 answers · asked by Shepard S 1 in Mathematics