Uranium, an important component of both nuclear weapons and nuclearreactors, has two major isotopes, U-238, which has a half-life of approximately billion years, and U-235, which has a half-life of approximately million years. Both were present in equal amounts at the time of thecreation of the Earth, billion years ago. How many years after the creationof the Earth had the amount of radiation from uranium decayed to half theamount present at the time of the creation of the Earth
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Answer:
Hello your question is poorly written below is the well written question
Uranium, an important component of both nuclear weapons and nuclear reactors, has two major isotopes, U-238, which has a half-life of approximately 4.5 billion years, and U-235, which has a half-life of approximately 700 million years. Both were present in equal amounts at the time of the creation of the Earth, 4.5 billion years ago. How many years after the creation of the Earth had the amount of radiation from uranium decayed to half the amount present at the time of the creation of the Earth
Answer : 140 billion years
Explanation:
Given that :
U-238 h1/2 = 4.5 billion years
U-235 h1/2 = 700 million years
At the beginning both Isotopes where present in equal amount
Determine the T years before the amount of Uranium decays to Half
T = ? N'2 = N1 / 2
we know that N = No ( 1/2 )^h where h = time / half-life time
attached below is the detailed solution of the given problem
Related Questions
- Explain why the term greenhouse effect is used to describe the theory of global
warming.
Does the greenhouse effect affect life on Earth? If yes, explain how?
What are the possible effects of a buildup of greenhouse gases in our atmosphere?
Answers
A student uses a sample of KOH stock solution and dilutes it to a total of 120 mL. If the diluted solution is 0.60 M KOH and its original concentration was 2.25 M, what was the volume of the original sample? *
1.4 mL
89 mL
32 mL
5.5 mL
(DON'T POST LINKS PLEASE)
Answers
Answer:
5.5
Explanation:
i think so?????????
The diluted solution of volume 120 ml has the molarity of 0.60 M. Then, the volume of the original solution with a molarity of2.25 M is 32 ml.
What is molarity ?The molarity of a solution is the ratio of the number of moles of its solute particles to the volume of solution in liters.
To solve the given problem, we can use the formula for dilution:
C1V1 = C2V2
where C1 is the initial concentration, V1 is the initial volume, C2 is the final concentration, and V2 is the final volume.
We are given that the diluted solution has a concentration of 0.60 M and a total volume of 120 mL. We are also given that the original concentration was 2.25 M, and we want to find the original volume.
Using the formula for dilution, we can write:
2.25 M x V1 = 0.60 M x 120 mL
Simplifying, we get:
V1 = (0.60 M x 120 mL) / 2.25 M
V1 = 32 mL
Therefore, the original volume of the KOH stock solution was 32 mL.
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Ethanol in the body is oxidized to acetaldehyde by liver alcohol dehydrogenase (LADH). Other alcohols are also oxidized by LADH. For example, methanol, which is mildly intoxicating, is oxidized by LADH to the quite toxic product of formaldehyde. The toxic effects of ingesting methanol (a component of many commercial solvents) can be reduced by administering ethanol. The ethanol acts as a competitive inhibitor of methanol by displacing it from LADH. This provides sufficient time for the methanol to be harmlessly excreted by the kidneys. If an individual has ingested 30 mL of methanol (a lethal dose), how much 100 proof whiskey (50% ethanol by volume) must be imbibed to reduce the activity of her LADH towards methanol to 5% of its original value? The adult human body contains ~40L of aqueous fluids throughout which ingested alcohols are rapidly and uniformly mixed. The densities of ethanol and methanol are both 0.79 g/cm3. Assume the KM values of LADH for ethanol and methanol to be 10-3 M and 10-2 M, respectively, and that Ki = KM for ethanol
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Answer: The changes are the mL of methanol ingestion (30mL) and the proof of the whiskey (40% ethanol; 80 proof), and the percentage of reduction (1%). I applied the formulas from the last post in reference to this question but am completely lost. The formulas used last time were: 2. Formulas Applied alpha=1 + ([etOH]/KetOH) (V[meOH]/V[etOH])= (Vmax*[meOH]/KmeOH+[meOH])/(Vmax*[meOH]/alpha*KmeOH+[meOH]) which reduces to (V[meOH]/V[etOH])=(alpha*KmeOH+[meOH])/(KmeOH+[meOH]) 3. My attempt Molarity of methanol: 30mL; which equates to 23.7g of methanol; in 40L that is equal to 0.5925 g/L Dividing the molecular weight by 32.04g/mol I get 0.0184925 which is approximately 0.02M; Km is 0.01M Since the molar mass of methanol and ethanol are two fold, I can multiply the g/l by 4. However, unlike the previous problem, I cannot multiply by 2 because I do not have 50% EtOH, so because 40 is less than 50 I assume to multiply by 2.5 yielding: (30mL)(4)(2.5)=300mL 300mL of EtOH to effectively reduce the Methanol to 1%.
Please help I have no idea where to start
Answers
Answer:
Download Ptable, it will show all of the elements, and you can click on them, and it will show all the information you need about them!
Explanation:
I hope this helps!!!!!
Identify the techniques used in the work-up and characterization of benzoic acid. The analytical method used to confirm the structure and functional groups of the product NMR spectroscopy The technique used to separate the pure product from any excess reagent, impurities, and byproducts Recrystallization The quick, numeric analysis used to characterize the product and assess the purity Melting point.
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Answer:
Explanation:
[tex]\text{From the list of the options given; we are to identify the suitable techniques} \\ \\ \text{for the characterization of benzoic acid.}[/tex]
[tex]\text{The analytical method used to confirm the structure and functional groups}\\ \\ \text{present in the product is} \ \ \mathbf{IR \ spectroscopy.}[/tex]
[tex]\text{The technique used to separate pure products from any excess reagents,} \\ \\ \text{impurities, and byproducts is}\ \ \mathbf{Recrystallization.}[/tex]
[tex]\text{The quick, numeric analysis done to characterize the product and assess the purity is}[/tex][tex]\mathbf{melting \ point.}[/tex]
Help this is for marks, who ever answers get brainliest
Answers
Answer:
Coal
Explanation:
thx for points :D
Answer:
Coal
Explanation:
your welcome<3
During a dry compression test, the first puff of the test shows 50 PSI and the maximum reading after 4 strokes is 150 PSI. This indicates A. that the cylinders are good. B. weak piston rings. C. a bad spark plug. D. a hole in the piston.
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One of the basic engine-diagnostic procedures that can be run is an engine compression test. All of the cylinders must have the same compression for the engine to run smoothly. There are just three possible ways for air to leak out of an engine and cause compression loss.
Exhaust or intake valve Engine rings (or piston, if there is a hole) An engine's head gasketThe procedures for conducting a compression testThe engine should be warmed to its typical operating temperature before testing in order to achieve the best results. The following procedures should be followed for an accurate compression test:
STEP 1: Dispose of each spark plug. As a result, the engine can be turned up to the same speed. Label all spark plug wires accurately.STEP 2 is to block the throttle open. This enables the engine to pull in the most air possible. Additionally, this step guarantees reliable compression test results.STEP 3 After inserting a compression gauge into a spark plug hole, start the engine. Four compression strokes of engine cranking should be performed in total. A puffing sound is produced after each compression stroke.EXAMPLE-If the ultimate, maximum value is 150 PSI, for instance, the reading following the first puff should be greater than 75 PSI. Low first-puff readings could be a sign of weak piston rings.STEP 4 Keep track of the highest readings, then compare the outcomes.Learn more about compression test here https://brainly.com/question/13274092
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if a compound formula mass was experimentally determined to be 58, the chemical formula could be?
Answers
Answer:
NaCl
Explanation:
If you follow traditional rounding, Na atomic mass is 23 and Cl atomic mass 35, 23 +35 = 58.
I was taught that Cl is one of the elements you round to 35.5, but this works if you’re not in an advanced chem class.
You have three containers each of which is connected to a fourth empty container. Three of the containers contain pure gases. In the first container oxygen is at 2 atm, nitrogen at 4 atm is in the second container, and argon at 1 atm is in the third. When you open the valve and mix the gases in the forth container, what is the pressure, PT, in the forth container
Answers
Answer: The total pressure is 7 atm
Explanation:
According to Dalton's law, the total pressure is the sum of individual pressures.
[tex]p_{total}=p_A+p_B+p_C...[/tex]
Given : [tex]p_{total}[/tex] =total pressure of gases = ?
[tex]p_{O_2}[/tex] = partial pressure of oxygen = 2 atm
[tex]p_{N_2}[/tex] = partial pressure of nitrogen = 4 atm
[tex]p_{Ar}[/tex] = partial pressure of argon = 1 atm
putting in the values we get:
[tex]p_{total}=2atm+4atm+1atm[/tex]
[tex]p_{total}=7atm[/tex]
Thus the total pressure is 7 atm
what does pen mean?.
Answers
Answer:
P = protons
E = electrons
N = neutrons
remember protons and neutrons (protons are positive and neutrons are neutral as you can already tell by their names) are found at the centre of the nucleus (positive mass). Whilst the electrons (negative) orbit around the shells
An FCC iron-carbon alloy initially containing 0.20 wt% C is carburized at an elevated temperature and in an atmosphere wherein the surface carbon concentration is maintained at 1.0 wt%. If after 51 h the concentration of carbon is 0.35 wt% at a position 3.9 mm below the surface, determine the temperature at which the treatment was carried out. You will need to use data in the two tables below to solve this problem.
Answers
Answer:
Explanation:
[tex]\text{From the information given:}[/tex]
[tex]C_o = 0.20 \ wt\% \\ \\ C_s = 1 \ wt\% \\ \\ t = 51 \ h \\ \\ x = 3.9 \ mm \\ \\ C_x = 0.35 \ wt\%[/tex]
[tex]\text{Using Fick's 2{nd} \ law \ of \ diffusion;} \\ \\ \dfrac{C_x- C_o}{C_s-C_o}= 1 - erf ( \dfrac{x}{2\sqrt{Dt}})[/tex]
[tex]\dfrac{0.35-0.20}{1-0.20}= 1 - erf ( \dfrac{x}{2\sqrt{Dt}})[/tex]
[tex]0.1875 = 1 - erf ( \dfrac{x}{2\sqrt{DT}}) \\ \\ erf ( \dfrac{x}{2\sqrt{DT}}) = 1 - 0.1875 \\ \\ erf ( \dfrac{x}{2\sqrt{DT}}) = 0.8125[/tex]
[tex]\text{To find the value of Z by Obtaining Data from Tabulation of Error Function}[/tex] [tex]\text{Table Values:}[/tex]
Z erf(z)
0.90 → 0.7970
0.95 → 0.8209
? → 0.8225
∴
[tex]\dfrac{z-0.90}{0.95-0.90}= \dfrac{0.8125-0.7970}{0.8209-0.7970}[/tex]
[tex]\dfrac{z-0.90}{0.05}= \dfrac{0.0155}{0.0239}[/tex]
[tex]z = 0.9324[/tex]
[tex]\text{To determine the diffusion coefficient;}[/tex]
[tex]erf (0.9324) = 0.8125 = erf (\dfrac{x}{2\sqrt{Dt}}) \\ \\[/tex]
[tex]\dfrac{x}{2 \sqrt{Dt}}= 0.9324 \\ \\ \dfrac{3.9 \times 10^{-3}}{2 \times \sqrt{D\times 51 \times 3600}} = 0.92324 \\ \\ \sqrt{D} = 4.88 \times 10^{-6} \\ \\ D = \sqrt{4.88 \times 10^{-6}} \\ \\ D = 2.38 \times 10^{-11} \ m^2 /s[/tex]
Definition of Acid, base and
salt
Answers
Answer:
nenrhj4rhty4bdwkwwa
Explanation:
Solubility is the mass in a given volume of a substance.
True
False
Answers
Answer: True
Explanation:
Use the following balanced reaction to solve:
P4 (s) + 6H2 (g) → 4PH3 (g)
How many grams of phosphorus trihydride will be formed by reacting 60 L of Hydrogen gas with an excess of P4?
Answers
Answer: 60.7 g of [tex]PH_3[/tex] will be formed.
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given volume}}{\text{Molar volume}}[/tex]
[tex]\text{Moles of} H_2=\frac{60L}{22.4L}=2.68moles[/tex]
The balanced chemical reaction is
[tex]P_4(s)+6H_2(g)\rightarrow 4PH_3(g)[/tex]
[tex]H_2[/tex] is the limiting reagent as it limits the formation of product and [tex]P_4[/tex] is the excess reagent.
According to stoichiometry :
6 moles of [tex]H_2[/tex] produce = 4 moles of [tex]PH_3[/tex]
Thus 2.68 moles of [tex]H_2[/tex] will produce=[tex]\frac{4}{6}\times 2.68=1.79moles[/tex] of [tex]PH_3[/tex]
Mass of [tex]PH_3=moles\times {\text {Molar mass}}=1.79moles\times 33.9g/mol=60.7g[/tex]
Thus 60.7 g of [tex]PH_3[/tex] will be formed by reactiong 60 L of hydrogen gas with an excess of [tex]P_4[/tex]
Consider the reactivity of phenol, bromobenzene, toluene, and nitrobenzene toward electrophilic aromatic substitution.
The most reactive compound is:_____
because the _______ character of the ______ increases the rate of the reaction.
The least reactive compound is ______
because the _______ character of the ________ decreases the rate of the reaction.
Answers
Answer:
The most reactive compound is: Phenol because the electron donating character of the alcohol group increases the rate of the reaction.
The least reactive compound is nitrobenzene
because the electron withdrawing character of the nitro group decreases the rate of the reaction.
Explanation:
PHENOL-: Any of a group of organic compounds with a hydroxyl (OH) group bound to a carbon atom in an aromatic ring is known as phenol. The word phenol is also the basic name for its simplest member, monohydroxybenzene (C6H5OH), also known as benzenol or carbolic acid, in addition to being the common name for the entire family.ELECTRON DONATING CHARACTER-: Via the carbon atom it is bound to, an electron donating group (EDG) has the net effect of increasing electron density in a molecule. EDGs alter a molecule's reactivity by increasing electron density on neighboring carbon atoms: EDGs make nucleophiles stronger.ALCOHOL GROUP-:Each of a class of organic compounds that have one or more hydroxyl (OH) groups bound to an alkyl group's carbon atom (hydrocarbon chain)is called Alcohol. Alcohols are organic compounds of water [tex](H_2O)[/tex] in which one of the hydrogen atoms has been substituted by an alkyl group, which in organic structures is usually expressed by R.NITROBENZENE-:The organic compound nitrobenzene has the chemical formula [tex](C_6H_5NO_2)[/tex]. It's a pale yellow oil that's insoluble in water and smells like almonds. Greenish-yellow crystals form when it freezes. It is made on a wide scale as a precursor to aniline from benzene. It is sometimes used as a solvent in the laboratory, especially for electrophilic reagents.ELECTRON WITHDRAWING GROUP-: An electron withdrawing group (EWG) is a type of group that reduces electron density in a molecule by bonding to a carbon atom. EWGs alter a molecule's reactivity by reducing electron density on neighboring carbon atoms.NITRO GROUP-: The nitro group is one of the most widely used explosophores (functional groups that combine to form a compound explosive). In addition, the nitro group is a heavy electron-withdrawing group. CH bonds alpha (adjacent) to the nitro group may be acidic due to this property.Exit ticket: Name the 2 factors that Terrestrial Biomes are separated by ___________ & ________
Answers
Answer:
temperature and rainfall
Explanation:
A separatory funnel contains the two immiscible liquids water and toluene. Use the given densities to determine which layer is on top and which is on the bottom in the binary mixture.
Solvent Density (g/mL)
toluene 0.87
water 0.998
Drag and drop each label into the box to indicate the position of the liquid in the mixture.
Top layer
Bottom layer
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Answer:
Top layer TolueneBottom layer WaterExplanation:
When two non-miscible liquids are put together, the one with the higher density will be on the bottom, while the one with the lower density will be on top.
Meaning that in this problem's case toluene would be on the top layer and water in the bottom layer.
Predict the product of this reaction
Al(s) + N2(g)—->
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can u identify a chemical equation for the saponification of olive oil as per your experiment?
I
Answers
What is a hot spot? {Must be in your own words} Plz hurry
Answers
Answer:
Hot spot is like someone who has data or min on there phone turn on their phone wifi so you can use it pretty much
Answer:
a hot spot is a form of wifi that u can use anywhere at anytime. it connects to near satalites or wifi towers. it allows you to use devices r games without the need for wifi.
Explanation:
help people i really need this
Answers
Choose the best answer
1. Gas A diffuses twice as fast as another gas B. If the density of the gas A is 2, the molecular mass of
(a)2
(b) 4
(c) 8
(d) 16
Answers
i think it is
(b) 4
:) hope its correct :)
A scientist places 10 ml of water in a test tube and heat it with flaming burner for 2 minutes. The liquid boils and escapes as a steam. This experiment is a good example of a
A chemical change
B physical change
C chemical property
D physical property
Answers
the easiest way to tell between is a chemical or physical change, is when you ask yourself this: did the substance change?
in this scenario, water and steam are still considered the same thing. they’re both different forms of water. if something in a reaction stays the same substance, it’s a physical change.
1L = 1000 mL
Molarity (M) = moles of solute / L of solution
Calculate the moles of NaCl required to prepare 250 mL of 1.5 M aqueous solution.
Answers
Answer:· 44 g NaCl Explanation: The problem provides you with the molarity and volume of the target
Explanation:
What is the other product for this reaction ? H3PO4 + Ca(OH)2 —> H20 + _________
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*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆**☆*――*☆*――*☆*――*☆
Answer: h3po4 + ca(oh)2 = h2o + ca3(po4)2
Explanation:
I hope this helped!
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- Zack Slocum
*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆**☆*――*☆*――*☆*――*☆
when are igneous rocks formed?
A. When layers of mud form inside Earth
B. When layers of mud are compressed
C. When melted rock solidifies
D. When solid rock melts
Answers
Answer:
C. When melted rock solidifies.
In order to determine the answer to a chemistry problem, a student first converted the given percentages to mole by assuming the sample size was 100 grams. Then the student divide by the smallest mole amount of the elements present. Finally the student used the ratios to write a formula. Which of the following best describes the problem the student likely solved?
a. Determined percent composition
b. None of the above
c. Determining molecular formula
d. Determining empirical formula
Answers
Answer: d. Determining empirical formula
Explanation:
Molecular formula is the chemical formula which depicts the actual number of atoms of each element present in the compound.
Empirical formula is the simplest chemical formula which depicts the whole number of atoms of each element present in the compound.
Step 1: If percentage are given then we are taking total mass is 100 grams. So, the mass of each element is equal to the percentage given.
Step 2 : convert given masses into moles
Step 3 : For the mole ratio, divide each value of moles by the smallest number of moles calculated
Step 4: The mole ratio gives the empirical formula of the compund.
Classify the following as either an element, compound, homogeneous mixture or
heterogeneous mixture:
sodium chloride
Answers
Sodium chloride is the chemical name for salt and is composed of sodium and chlorine, so it is a compound.
im not sure if it is a molecule or an atom
Answers
Answer:
the first one
Explanation:
I looked it up:P
Only the 2nd answer is right, uncheck the 1st one
Explanation:
If we had a chemical formula like [tex]3(O_{2} )[/tex] the 3 means there are 3 molecules of [tex]O_{2}[/tex]. The 2 means there are two atoms of oxygen in each molecule.
When one gram of liquid water at its boiling point is changed into water vapor
1.
334 J/g is gained from the surrounding environment
2.
334 J/g is released into the surrounding environment
3
2260 J/g is gained from the surrounding environment
4
2260 J/g is released into the surrounding environment
Answers
Answer: 2260 J/g is gained from the surrounding environment
When one gram of liquid water at its boiling point is changed into water vapor, 2260 J/g of energy is gained from the surrounding environment.
What is heat of vaporization?Heat of vaporization is the amount of heat that is required by any body during their transition process from liquid state to vapor state, at a particular temperature i.e. no change in temperature during whole process.
During the transition of one gram of liquid water into water vapor at its boiling point of 100°C, 2260 J/g energy is absorbed by the water for the formation of vapor.
Hence, option (3) is correct.
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