1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
nikitadnepr [17]
3 years ago
11

How much of a sample remains after three half-lives have occurred? 1/16 of the original sample 1/9 of the original sample 1/8 of

the original sample 1/3 of the original sample
Chemistry
2 answers:
Drupady [299]3 years ago
5 0
For this question, assume that you have 1 compound. This compound is divided in half once, so you are left with 0.5. That 0.5 that remains is divided in half again, this is the second half-life, and you are left with 0.25. The final half life involves dividing 0.25 in half, which means you are left with 0.125. For the answer to make sense, you need to know your conversions between decimals and fractions. To make it simple, if you have 0.125 and you times it by 8, you are left with your initial value of 1. Therefore, after three half-lives, you are left with 1/8th of the compound.
miskamm [114]3 years ago
3 0
1/8, yay math. so the third answer
You might be interested in
Using the bond energy data from your text (or the internet), determine (show calculations for) the approximate enthalpy change ,
aleksley [76]

Answer:

∆H=  <u>438 KJ/mol</u>

Explanation:

First, we have to find the <u>energy bond values</u> for each compound:

-) Cl-Cl = 243 KJ/mol

-) F-F = 159 KJ/mol

-) F-Cl = 193 KJ/mol

If we check the reaction we can calculate the <u>number of bonds</u>:

Cl_2_(_g_)~+~3F_2_(_g_)~->~2ClF_3_(_g_)

In total we will have:

-) Cl-Cl = 1

-) F-F = 3

-) F-Cl = 6

With this in mind. we can calculate the <u>total energy for each bond</u>:

-) Cl-Cl = (1*243 KJ/mol) = 243 KJ/mol

-) F-F = (3*159 KJ/mol) = 477 KJ/mol

-) F-Cl = (6*193 KJ/mol) = 1158 KJ/mol

Now, we can calculate the total energy of the <u>products</u> and the <u>reagents</u>:

Reagents = 243 KJ/mol + 477 KJ/mol = 720 KJ/mol

Products = 1158 KJ/mol

Finally, to calculate the total enthalpy change we have to do a <u>subtraction</u> between products and reagents:

∆H= 1158 KJ/mol-720 KJ/mol = <u>438 KJ/mol</u>

<u />

I hope it helps!

7 0
3 years ago
Which of the following provides the most evidence for the theory of plate tectonics?
zhenek [66]

Answer:

i dunno

Explanation:

m xlaklXMLXL

5 0
3 years ago
Explain (not just list) where you observe reflection, refraction, and absorption of light in your everyday activities
DerKrebs [107]

Answer:

Reflection: you look in the mirror. Refraction: You put a straw in a glass of water, and it looks like it broke. Absorption: If you have a black sweater and you wear it out in the cold, the black sweater is going to hold in heat better than a lighter sweater because the black sweater absorbs light .

7 0
3 years ago
Predict the spontaneity of a reaction (and the temperature dependence of the spontaneity) for each possible combination of signs
Akimi4 [234]

Answer and Explanation:

At constant pressure and constant temperature, the Gibbs free energy of a process is given by the following equation:

ΔG= ΔH - T ΔS

The process is spontaneous when ΔG<0. For this, there are four alternatives depending on the signs of ΔH and ΔS and the temperature (T):

1) ΔH negative, ΔS positive ⇒ b)The reaction will be spontaneous at all temperatures.

ΔG= (-H) - T (+S)   ⇒ ΔG<0 always

2) ΔH positive, ΔS negative ⇒ c)The reaction will be nonspontaneous at all temperatures.

ΔG= (+H) - T (-S)   ⇒ ΔG>0 always

3) ΔH negative, ΔS negative ⇒ d)The reaction will be spontaneous at low temperature, but nonspontaneous at high temperature.

ΔG= (-H) - T (-S)  ⇒ ΔG<0 if TΔS is lower than ΔH, because is the positive term

4)ΔH positive, ΔS positive ⇒ a)The reaction will be nonspontaneous at low temperature, but spontaneous at high temperature.

ΔG= (+H) - T (+S) ⇒ ΔG<0 if TΔS higher than ΔH because is the negative term

8 0
3 years ago
Chemistry test bound theories
liq [111]

covalent bond is firmed between two atoms

5 0
3 years ago
Other questions:
  • _____________ are solvents made from natural sources such as pine and citrus oils.
    11·1 answer
  • which law is used to determine the relationship between the volume and the number of moles in the equation
    13·1 answer
  • How many milliliters of a 1.25 molar hydrochloric acid solution would be needed to react completely with 60 grams of calcium
    7·1 answer
  • Is tap water a mixture or a pure substance
    5·2 answers
  • What is molar mass of manganese
    12·1 answer
  • What is the Hazard of Silicon?
    10·1 answer
  • As a group, all of the f-block elements (those that use their remaining electrons to fill an f sublevel orbital) are known as th
    7·1 answer
  • 4 ) A sample of gas has a pressure of 1 atm while occupying 300 What volume will the gas occupy at 2 atm ? 10 points total . Sho
    7·1 answer
  • Answer pls ASAP will mark the brainliest
    15·2 answers
  • what would happen if we lost our planets core on earth blew up, would we all die or will we lose gravity or suficate, pls help.
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!