Answers
Answer:
50 years
12.5 g
2.5 g
Explanation:
The half-life is the time it takes for the sample to become half of the original. At 0 years, none of the sample has decayed. At 50 years, half of the sample has decayed. This means that the half-life is 50 years.
If you look at the diagram, at 150 years, you will have 1/8 of the original amount. If you start with 100 g, you will have 12.5 g after 150 years.
100/8 = 12.5
Looking at the diagram, you can see that at 100 years, you will have 1/4 of the original amount. If you start with 10 g, you will have 2.5 g after 100 years.
10/4 = 2.5
Related Questions
The elementary gas-phase reaction
A → B
takes place isobarically and isothermally in a PFR where 63.2% conversion is achieved. The feed is pure A. It is proposed to put a CSTR of equal volume upstream of the PFR. Based on the entering molar flow rate to A to the first reactor, what will be the intermediate from the CSTR, X1, and exit conversion from the PFR, X2, based on the feed to first reactor?
Answers
Answer:
Xa1 = 0.5
Xa2 = 0.815
Explanation:
Elementary gas-phase reaction
A → B taking place isobarically and isothermally and the feed is Pure
conversion rate = 63.2%
The intermediate from the CSTR (XA1 ) = 50%
conversion in the PFR at the exit ( XA2 ) = 0.815
Attached below is the detailed
If 20.0 kilocalories of energy were added to 80.0 g of water, what change in temperature would be observed?
Please explain how.
Answers
Answer:
250 °C.
Explanation:
From the question given above, the following data were:
Heat (Q) required = 20.0 kilocal
Mass (M) of water = 80 g
Change in temperature (ΔT) =.?
Next, we shall convert 20.0 Kilocalories to calories. This can be obtained as shown below:
1 kilocal = 1000 Cal
Therefore,
20 kilocal = 20 kilocal × 1000 Cal / 1 kilocal
20 kilocal = 20000 calories
Therefore, 20 kilocalorie is equivalent to 20000 calories.
Finally, we shall determine the change in temperature observed as follow:
Heat (Q) required = 20000 Cal
Mass (M) of water = 80 g
Specific heat capacity (C) of water = 1 Cal /gºC
Change in temperature (ΔT) =.?
Q = MCΔT
20000 = 80 × 1 × ΔT
20000 = 80 × ΔT
Divide both side by 80
ΔT = 20000 / 80
ΔT = 250 °C
Therefore, the change in temperature observed is 250 °C
I WILL GIVE BRAINLIEST! ANSWER ASAP! If 50 grams of vinegar and 10 grams of baking soda are poured into a container, what will the final mass of the products be?
Answers
Answer: Wouldn't that just be 60 grams?
Explanation:
50+10=60
Help Please!! (The Question is in the picture!)
Answers
Answer:
the answer that best describe the two methods is c
Please Help. Will mark as Brainliest
Answers
Answer:
You are correct. The answer is [tex]X_{3} Z[/tex].
Which material is typically used as a thermal insulator
Answers
Answer: plastic, wood, rubber
Explanation:
Answer:
Lots of items.
Explanation:
Fiber, mineral wool, and corks.
A solid that forms from liquids in a chemical reaction is called a
PLZ HELP
Answers
Answer:
precipitate
Explanation:
The diagram show the box for an element in the periodic table . What is the atomic mass of the element shown .
Answers
Answer:32.1
Explanation:
Give two examples. What is prey?
Answers
Answer: deer and a rabbit or zebra
A 130.3 g piece of copper (specific heat 0.38 J/g･°C) is heated and then placed into 400.0 g of water initially at 20.7°C. The water increases in temperature to 22.2°C. What is the initial temperature of the copper? (The specific heat of water is 4.18 J/g･°C).
Answers
Answer:
Approximately [tex]72.9\; \rm ^\circ C[/tex], assuming that this system is insulated properly.
Explanation:
Calculate the amount of energy that the water here has gained (using the increase in its temperature.)
[tex]\begin{aligned} Q(\text{water}) &= c(\text{water}) \cdot m(\text{water}) \cdot \Delta T(\text{water}) \\ &=4.18 \times 400.0 \times (22.2 - 20.7) \approx 2508.0\; \rm J \end{aligned}[/tex].
Assume that this system (copper and water) is well-insulated and has no heat exchange with its surroundings. The amount of energy that water gained should be equal to the of energy that copper has lost. However, the sign of the energy change of copper should be negative because copper had lost energy:
[tex]Q(\text{copper}) = -Q(\text{water}) \approx -2508.0\; \rm J[/tex].
Calculate the temperature change of this piece of copper. Note, that this temperature change is the difference between the initial temperature of the copper piece and the final temperature [tex]22.2\; \rm ^\circ C[/tex] of the system.
[tex]\begin{aligned}\Delta T(\text{copper}) &= \frac{Q(\text{copper})}{c(\text{copper}) \cdot m(\text{copper})} \approx \frac{-2508.0}{130.3 \times 0.38} \approx 50.65\; \rm ^\circ C\end{aligned}[/tex].
Calculate the initial temperature of this piece of copper given its final temperature and the change to its temperature:
[tex]\begin{aligned}T(\text{copper, initial}) &= T(\text{copper, final}) - \Delta T(\text{copper}) \\ &\approx 22.2 + 50.65 \approx 72.9\; \rm ^\circ C\end{aligned}[/tex].
How does water shape earth surfaces
Answers
Answer:
jeanne I have to be at work at school
The economy of each region was shaped by all of the following factors, except:
A. Geography
B. Climate
C. Language
D. Population
Answers
Answer:
Language
Explanation:
this is very obvious not to be mean
How does rainfall affect a biome !?!?!!??!
Answers
Please answer 11 to 13 to receive 10 Brainly points. Please read the bullet points to under the questions. And check the molecular formula image.
Answers
Answer:
11 yes
12 H2O( water molecules)
13 3H2O( water molecules)
Explanation:
Sry, my phone's a potato, so I didn't read it properly, so I'm not sure about the question 11.
11-yes, they stay together, but they release 3 molecules of OH an H.
12- here it talks about what will happen with OH and H: they will be H2O (water molecules).
13- and here we end it with the informations that we got: 3 fatty acids+ glycerol---> fat+ 3H2O( the 3 H and 3 OH)
9.87 x 10^-5km - 8.76 x 10^-6km
Answers
A rectangular solid has a length of 3 cm height of 4 cm and a Width of My 5 cm what is a solid volume
Answers
Volume = length x width x height
Volume = 3cm x 5cm x 4cm
Volume = 60cm3
Hope this helps! :)
Which of the following groups makes a neutral salt of the form AB
Answers
Answer:
Groups II and VI
Explanation:
Hello.
In this case, regarding cations from groups I whose oxidations states are +1, II whose oxidation states are +2 and III whose oxidation states are +3 we can see that when they combine with nonmetallic anions they exchange the charges via subscripts. In such a way, when bonding for instance calcium ions with sulfide ions, we obtain:
[tex]Ca^{2+}S^{2-}=Ca_2S_2[/tex]
Which can be simplified to give:
[tex]CaS[/tex]
If we do the same for oxygen, selenium and tellurium, we find the same form since nonmetals from group VIA could form anions with -2 as they need two electrons to attain the octet, therefore, answer is groups II and VI.
Regards.
Different kind of London are used in eyeglasses to help people with eye conditions
Answers
Answer:
true
Explanation:
WHAT IS THE DENSITY OF A BLOCK WITH A
VOLUME OF 24 ML AND A MAS 3.2 G?
Answers
Answer:
The answer is 7.5 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
So we have
[tex]density = \frac{24}{3.2} \\ [/tex]
We have the final answer as
7.5 g/mLHope this helps you
What body system controls the brain, spinal cord, nerves, and sense organs?
Answers
Answer:
The central nervous system
The concentration of two reactants is decreased by the same amount. How
will this change in concentration affect the reaction?
A. The reaction rate will increase by the same amount the concentrations were increased
B. The change in concentration will affect the rate of the reaction according to the rate law
C. The change in the reaction rate depends on the balanced chemical equation
D. The reaction rate will decrease by the same amount the concentrations were decreased
Answers
A woman is brought into the emergency room experiencing nausea and vomiting. She is also hyperventilating. She says that she ingested a bottle of aspirin about two hours earlier. Aspirin (acetylsalicylic acid) is converted to salicylic acid in the stomach. Assuming 100% conversion to salicylic acid.
Required:
Calculate the percentage of protonated and unprotonated forms of salicylic acid in her stomach, given a pH of 2.0 for the stomach.
Answers
Answer:
Protonated form: 96.87%
Unprotonated form: 3.13%
Explanation:
To find the percentage of protoned and unprotoned forms of salicylic acid we must use Henderson-Hasselbalch equation:
pH = pKa + log [A⁻] / [HA]
Where pKa of salicylic acid is 3.49; [A⁻] is the unprotonated form and [HA]:
2.0 = 3.49 + log [A⁻] / [HA]
0.03236 = [A⁻] / [HA] (1)
And as:
[A⁻] + [HA] = 100% (2)
Replacing (2) in (1):
0.03236 = 100 - [HA] / [HA]
0.03236 [HA] = 100 - [HA]
1.03236[HA] = 100
[HA] = 96.87%And [A⁻]:
[A⁻] = 100 - 96.87
[A⁻] = 3.13%
Ammonia molecule has got trigonal pyramidal geometry even though central atom gets sp3 hybridization. Give reason.
Answers
In NH3 N shares 3 electrons with H
2 electrons are not bonded with
So there are 3 bonding pairs and one lone pair of electrons
Lone pair - bond pair repulsion is greater than bond pair - bond pair repulsion
So they arrange in a way that minimizes repulsion forming a trigonal pyramidal shape
sapling is to a tree as a _______ is to a horse... help meee
Answers
Which statement best describes a scientific theory?
A) It is a scientific fact that no longer requires any evidence to support it.
B) It is a general statement that is supported by many scientific observations.
C) It is an educated guess that can be tested by experimentation.
D) It is a collection of data designed to provide support for a prediction.
Answers
Answer:
B
Explanation:
Just because it is a theory doesnt mean it does not need evidence or odservations.
Answer:
it’s c
Explanation:
it’s c
Uneven heating of Earth's surface creates pressure differences that result in ____________.
Answers
Answer:
Updrafts (and can cause thunderstorms and other violent weather.)
Good luck, hope this helped!
Which of the following is true about metallic bonds?
o A. Electrons are strongly attracted to the nucleus.
B. Electrons of metals are always shared.
C. Electrons are highly stable.
O
D. Electrons are delocalized.
Answers
Answer:
D: electrones are delocalized
The metallic bond has been characterized with the de localization of the electrons. Thus, option D is correct.
Metallic bond has been the type of inter-molecular force that has been found in between the metal atoms.
Metals atom have been capable of donating the electrons in order to become stable. In the metallic bond, there has been the de-localization of the electrons of p orbitals that has been resulted in the electron cloud for the formation of the metallic bond.
Thus, the metallic bond has been characterized with the de localization of the electrons. Thus, option D is correct.
For more information about the metallic bond, refer to the link:
https://brainly.com/question/10714037
is water a mineral? HELP ASAP!!!!
Answers
Answer:
Water is not a mineral because it is not a solid.
Explanation: If water were turned into ice then it would be considered if water were turned into ice then it would be considered a mineral.
A calibration curve was created to determine the quantity of protein in a solution. The calibration curve has the form of a straight line with the equation A = 0.0182 x +0.007 where A is the corrected absorbance of the solution and x is quantity of protein in the solution in units of micrograms (μg). Determine the quantity of protein in a solution that has an absorbance of 0.207. A blank solution has an absorbance of 0.050 .
Answers
Answer:
(a) 10 quantities of protein
(b) 2 quantities of protein
Explanation:
Given
[tex]A = 0.0182 x +0.007[/tex]
Solving (a):
Solve for x when A = 0.207
Substitute 0.207 for A
[tex]A = 0.0182 x +0.007[/tex]
[tex]0.207 = 0.0182x + 0.007[/tex]
Solve for 0.0182x
[tex]0.0182x = 0.207 - 0.007[/tex]
[tex]0.0182x = 0.200[/tex]
Solve for x
[tex]x = 0.200/0.0182[/tex]
[tex]x = 10.989010989[/tex]
[tex]x = 11[/tex] (Approximated)
Solving (b):
Solve for x when A = 0.050
Substitute 0.050 for A
[tex]A = 0.0182 x +0.007[/tex]
[tex]0.050 = 0.0182x + 0.007[/tex]
Solve for 0.0182x
[tex]0.0182x = 0.050 - 0.007[/tex]
[tex]0.0182x = 0.043[/tex]
Solve for x
[tex]x = 0.043/0.0182[/tex]
[tex]x = 2.36263736264[/tex]
[tex]x = 2[/tex] (Approximated)
The emission spectrums are known for the elements below. Line spectra for boron, lithium, hydrogen, helium, potassium and unknown sample. Boron has 3 purple lines, 1 blue line, 2 blue-green lines and 2 orange lines. Lithium has 2 purple lines, 2 blue lines, 2 blue-green lines, 1 orange line and 1 red line. hydrogen has one line of each purple, blue, blue-green and red. helium has 3 purple lines, 3 blue lines, 3 blue-green lines 1 yellow line and 2 red lines. Potassium has 8 purple lines, 6 blue-green lines, 10 green lines, 3 yellow lines, 2 orange lines and 6 red lines. The unknown sample has Potassium has 8 purple lines, 6 blue-green lines, 10 green lines, 3 yellow lines, 2 orange lines and 6 red lines. What elements are in the unknown sample? Check all that apply. boron lithium hydrogen helium potassium
Answers
Answer:
The Answer is (B) lithium and (E) potassium
The elements are in the unknown sample of emission spectrums is lithium and potassium. correct options are B and E.
What is emission spectrums?The emission spectrum of elements are is a formation of different types of lines of different colors and are of different wavelengths when their is emission of the light through a chemical substance is known to be emission spectrums.
The line of red color have the longest wavelength and can be measured easily with the help of spectrophotometer during the emission of light passing through it.
Therefore, elements are in the unknown sample of emission spectrums is lithium and potassium. correct options are B and E.
Learn more about emission spectrum, here:
https://brainly.com/question/12472637
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