If the half-life of a radioactive isotope is 3 million years, what percent of the isotope is left after 9 million years
Answers
After 9 million years, only 12.5% of the original isotope will remain.
The half-life of a radioactive isotope is the amount of time it takes for half of the atoms in a sample to decay. In this case, the half-life of the isotope is 3 million years, which means that after 3 million years, half of the isotope will have decayed, and half will remain. After another 3 million years (for a total of 6 million years), half of the remaining isotope will have decayed, leaving 25% of the original amount.
After another 3 million years (for a total of 9 million years), another half of the remaining isotope will have decayed, leaving 12.5% of the original amount.
To find out what percent of the isotope is left after 9 million years, we can use the formula:
Percent remaining =\((0.5)^{(t/h)\) x 100
Where t is the time elapsed and h is the half-life of the isotope. Plugging in the values, we get:
Percent remaining = \((0.5)^{(9/3)\) x 100
Percent remaining = \((0.5)^3\) x 100
Percent remaining = 12.5%
Therefore, after 9 million years, only 12.5% of the original isotope will remain. The isotope has undergone three half-lives, each time reducing its quantity by half, resulting in a significant decrease in the overall amount present.
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Related Questions
Calculate the mass (in g) of 2.1 x 1020 atoms of Os.
Answers
Answer:
here's the procedure to find it friend
Explanation:
How do you find the mass in grams of an atom?
In order to determine the mass of one atom of an element, you must determine its molar mass, which is its atomic weight on the periodic table in g/mol, and you need to know the relationship between moles and the number of atoms: 1 mol of atoms = 6.022×1023 atoms . Then divide the molar mass by 6.022×1023 atoms/mol .
A physical change can be distinguished from a chemical change because during a physical change- a. the properties of the substance may change, but no new substances are produced b. the properties of the substance change for only a short time but will return to their original state. c. an entirely new substance with new properties forms as a result of the change d. a new substance is produced, but the new substance has properties identical to the original substance
Answers
Answer:
C. an entirely new substance with new properties forms as a result of the change
Answer:
. an entirely new substance with new properties forms as a result of the change
Explanation:
According to the Law of Conservation of Matter, what happens to atoms during a chemical reaction?
1. More atoms are produced to form new substances.
2. Nothing; they stay the same.
3. The atoms are rearranged to form new substances.
4. Atoms are converted into energy during the chemical reaction.
Answers
Answer: 3. The atoms are rearranged to form new substances.
According to law of conservation of matter, atoms are rearranged to form new substances in a chemical reaction.
What is law of conservation of matter?According to law of conservation of matter, it is evident that matter can be neither created nor destroyed rather it is restored at the end of a chemical reaction .
Law of conservation of matter and energy are related as matter possesses mass and mass and energy are directly proportional which is indicated by the equation E=mc².Concept of conservation of matter is widely used in field of chemistry and fluid dynamics.
Law needs to be modified in accordance with laws of quantum mechanics under the principle of matter and energy equivalence.This law was proposed by Antoine Lavoisier in the year 1789.
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Is 2H2 + O2=2H2O a balanced equation
Answers
Explanation:
Yes, the equation is balanced. There are the same number of Hydrogen (H) and Oxygen (O) atoms on both sides of the equation.
In each sentence, choose the number that represents the correct answer. A. Under certain conditions, 6 units of hydrogen will burn in 1 second. This process releases energy at a rate of 286/572/1,716 kJ per second. B. Under the same conditions, 1 unit of ethanol will burn in 1 second. This process releases energy at a rate of 686 /1,371/8,226 kJ per second. C. Under these conditions, hydrogen / ethanol will release more energy in 1 second.
Answers
C. Under these conditions, hydrogen / ethanol will release more energy in 1 second is the correct answer.
The energy change that occurs when one mole of a compound is burnt in excess oxygen under standard conditions is called the standard enthalpy change of combustion. The standard enthalpy change of combustion of hydrogen is -286kJ/moL.Ethanol combustion is an exothermic process. The chemical reaction that occurs when ethanol burns releases a lot of heat and energy, 277.7 kJ per mole of ethanol, in addition to the creation of new compounds. In conclusion, ethanol burns by combining with oxygen to create carbon dioxide, water, and heat.The standard enthalpy change of combustion is the energy change that happens when one mole of a compound burns in excess oxygen under typical conditions. Enthalpy change for hydrogen combustion is typically -286kJ/moL.To know more about Hydrogen check the below link:
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please help me
16 1 point What is the decay rate of a sample of Oxygen-21 if the sample has 8.31x1017 atoms and a decay constant of 0.203/s? 4.09x1018Bq 1.69x10¹7Bq 0.203Bq 2.44x10-1⁹Bq Previous
Answers
decay rate of approximately 1.69x10^17 Bq (becquerels),
The decay rate of a radioactive sample is determined by the number of radioactive atoms present and the decay constant, which represents the probability of decay per unit of time.
To calculate the decay rate, we multiply the number of atoms in the sample by the decay constant. In this case, the sample has 8.31x10^17 atoms and a decay constant of 0.203/s. Multiplying these values gives a decay rate of approximately 1.69x10^17 Bq (becquerels), which represents the number of decays per second in the sample.
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what is the electron configuration for aluminum
Answers
The electron configuration of aluminum is 1s2 2s2 2p6 3s2 3p1.
The fermentation of C6H12O6 will produce carbon dioxide and
Answers
Answer:
ethanol
Explanation:
CO2 is carbon dioxide
C2H5OH is ethanol and we know that because that is what is left after taking out the CO2
PLEASE I NEED HELP ILL GIVE BRAINLYEST
What percentage increase did CO2 experience from 1800 to 2004 AD?
Answers
The percentage of CO2 increased 48 percent. Hope this helped!
which substance is an arrhenius base
Answers
Answer:
sodium hydroxide
Explanation:
The common examples of Arrhenius base includes NaOH (sodium hydroxide), KOH (potassium hydroxide), Ca(OH)2 (calcium hydroxide), Mg(OH)2 (magnesium hydroxide), NH4OH (ammonium hydroxide), etc.Oct 21, 2020
what is the subscript of cl2
Answers
What is the percent yield of ferrous sulfide if the actual yield is 220.0 g and the theoretical yield is 275.6 g? Use Percent yield equals StartFraction actual yield over theoretical yield EndFraction times 100.. 12.5% 55.6% 79.8% 87.9%
Answers
Answer:
79.8%
Explanation:
Percentage yield = actual yield / theoretical yield x 100%
Percentage yield = 220.0 / 275.6 x 100%
=79.8%
The percent yield of of ferrous sulfide if the actual yield is 220.0 g and the theoretical yield is 275.6 g is 79.8%.
What is percent yield?Percent yield is defined as the ratio of actual yield to the theoretical yield multiplied by 100. If the actual and theoretical yield are same then the percent yield is 100%.If actual yield is less than the theoretical yield then the percent yield is less than 100%.Reason of this condition arising is the incompletion of reaction or loss of sample during recovery process.
In cases where percent yield is over 100% it indicates that more sample is recovered than the predicted amount.This condition arises when there are other simultaneous reactions taking place leading to the formation of product. It can also arise if there is incomplete removal of impurities from the sample .
In the given example, percent yield can be found out by substituting values in mentioned formula. percent yield,=220/275.6×100=79.8%.
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Phenol (c6h5oh, also called carbolic acid) has a pka of 9. 89. It is used to preserve body tissues and is quite toxic. Calculate the percent ionized in 0. 0786 m phenol--a dilute solution.
Answers
This problem is providing us with the pKa of phenol and its initial concentration. It is asking for the percent ionization it exhibits in water. At the end, the answer turns out to be 0.00405 %.
Percent ionizationIn chemistry, when acids and bases dissolve in water, they undergo ionization, a process whereby they split into a cation and an anion. In this case, since phenol has a pKa of 9.89, one can write the following ionization reaction:
\(C_6H_5OH(aq)+H_2O\rightleftharpoons C_6H_5O^-(aq)+H_3O^+(aq)\)
And the equilibrium constant can be written as:
\(K=\frac{[C_6H_5O^-][H_3O^+]}{[C_6H_5OH]} =\frac{x^2}{0.0786} =10^{-9.89}\\\\1.29x10^{-10}=\frac{x^2}{0.0786}\)
Which can be solved for x with:
\(x=\sqrt{1.29x10^{-10}*0.0786} \\\\x=3.19x10^{-6}M\)
Finally, the percent ionization:
\(\%ioniz=\frac{3.18x10^{-6}M}{0.0786M}*100\%\\ \\\%ioniz=0.00405\%\)
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quotes for climate change
for example ‘’CLIMATE CHANGE IS REAL!’’
‘’SMALL CNAGES CAN MAKE A DIEFFENCE!’’
give me 3 and more
Answers
Answer:
Explanation:
WAKE FOR CLIMATE CHANGE IS NOT FAKE
SAVE THE GLACIERS
HELP THE ARCTIC ANIMALS
What occurs when a neutron strikes a stable isotope and causes it to become unstable? A. Energy to mass conversion
B. None of these
C. Natural radioactive decay
D. Nuclear fission
Answers
Answer:
A
Explanation:
become unstable and split which will add more mass to it I believe but then again if it splits theidI don't know if it adding mass or just keeping the same so either A or B
1. Ethanol and 2,6-dimethylphenol both have hydroxyl groups that can be deprotonated by a base. Why does ethanol act as a solvent but not as a nucleophile under the conditions used in this experiment
Answers
Anions are solvated in protic hydrogen-bonding solvents (such as ethanol). Consequently, nucleophiles are less reactive. Since soft nucleophiles are less strongly solvated than hard nucleophiles, these solvents boost the relative reactivity of soft anions.
Ethanol is either a nucleophile or a base.The ethanol is a base Because carbocation is an extremely reactive species, a base or nucleophile as weak as ethanol can replace or remove it. SN1 and E1 would not be conceivable without the carbocation or a strong departing group.
How do solvents impact anionic nucleophile's reactivity?In polar aprotic solvents, nucleophilic substitution reactions of anionic nucleophiles often proceed more quickly. The normal relative reactivity order in such solvents (like DMSO)is Anions are solvated in protic hydrogen-bonding solvents (such as ethanol). Consequently, nucleophiles are less reactive.
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which type of wind is responsible for moving state to state
Answers
What is the full name for IUPAC
Answers
Answer:
International Union of Pure and Applied Chemistry
Explanation:
Hope this helps (:
Answer:
International Union of Pure and Applied Chemistry
Help me pls!
What is heliuim?
Answers
Answer:
it's a chemical Element
Explanation:
symbol He
atomic number 2.
When the first American astronauts were planning to walk on the Moon, they knew that the gravity on the Moon was less than the gravity on Earth. With this information, what did the astronauts expect to be MOST different on the Moon? Select one: a. their mass b. their height c. their weight d. their volume
Answers
Answer:
Their weight.
Explanation:
Weight is the measurement of gravity pushing you down, so with less gravity there would be less weight.
The astronauts expect their weight to be different on the Moon
Definition of weightWeight is simply defined as the gravitational pull of the earth on an object. It is measured in Newton.
Description of weightThe weight of an object varies with location because of gravity.
The weight of an object is related to it's mass according to the following equation:
Weight = mass × Acceleration due to gravity
Since the gravity of the Moon is lesser than that of the Eearth, the astronauts certainly knew that their weight will be different on the Moon.
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Susie has a box that has a mass of 6g and volume of 2 cm3
. What is the Density of the box?
Answers
Suppose the car now accelerates from 0 m/s to 30. 0 m/s in 5. 00 s. If the wheels have a radius of 24. 1 cm, what is their angular acceleration?.
Answers
If the car now accelerates from 0 m/s to 30. 0 m/s in 5. 00 s. If the wheels have a radius of 24. 1 cm, then their angular acceleration is 24.9 rad/s².
To calculate the angular acceleration of the car's wheels, we need to first find their angular velocity. We know that the car accelerates from 0 m/s to 30.0 m/s in 5.00 s, so we can calculate the average acceleration:
a = (vf - vi)/t = (30.0 m/s - 0 m/s)/5.00 s = 6.00 m/s²
Next, we can use the formula for linear acceleration in terms of angular acceleration and radius:
a = αr
where α is the angular acceleration and r is the radius of the wheels. Solving for α, we get:
α = a/r = 6.00 m/s² / 0.241 m = 24.9 rad/s²
Therefore, the angular acceleration of the car's wheels is 24.9 rad/s².
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33
-Involves electrons
-Happens outside atomic
nucleus
-Releases relatively small
amounts of energy
-Involves neutrons
-Happens inside atomic
nucleus
-Releases relative large
amounts of energy
How should the student label each circle in this diagram?
reaction A: chemical; reaction B: nuclear
reaction A: nuclear: reaction B: chemical
reaction A: strong nuclear; reaction B: weak nuclear
reaction A: weak nuclear; reaction B: strong nuclear
Answers
Reaction A is chemical, while Reaction B is nuclear, is the proper response. Electrons are involved in chemical processes that take place outside of the atomic nucleus and release modest quantities of energy.
On the other hand, nuclear processes, which take place inside the atomic nucleus and include neutrons, release comparatively high levels of energy. The terms "weak nuclear" and "strong nuclear," which describe the forces that hold protons and neutrons together in the nucleus, are inapplicable in this situation.
These forces are not present in chemical and nuclear reactions, which are fundamentally distinct processes. Nuclear reactions entail the conversion of one element into another, whereas chemical reactions require the building and breaking of chemical bonds.
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If a population of mice on an island have only the a1 allele, what percentage of their offspring (the zygotes formed through sexual reproduction) will have the genotypes of a 1a1? a1 a2? a2 a2?
Answers
The percentage of offspring with the genotypes a1a1, a1a2, and a2a2 will be 100% for a1a1 and 0% for both a1a2 and a2a2.
If a population of mice on an island has only the a1 allele, it means that all individuals in the population possess the genotype a1a1. In order to determine the percentage of offspring with specific genotypes, we need to understand the principles of Mendelian genetics and the laws of inheritance.
Mendel's law of segregation states that during the formation of gametes (sperm and eggs), the two alleles for a given gene segregate from each other, resulting in each gamete carrying only one allele. In this case, since all mice have the genotype a1a1, each individual will produce gametes carrying only the a1 allele.
When two a1a1 mice reproduce, each parent will contribute one a1 allele to the offspring. As a result, all the zygotes formed will have the genotype a1a1. None of the offspring will possess the a2 allele, as it is not present in the population.
In conclusion, all the offspring will have the genotype a1a1.
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which of the following chemical reactions represents an acid-base reaction? a. hbr koh ↔ kbr h2o b. nh4oh kcl ↔ koh nh4cl c. zncl2 mgso4 ↔ znso4 mgcl2 d. h2so4 cacl2 ↔ caso4 hcl
Answers
The chemical reaction that represents an acid-base reaction is:
a. HBr + KOH ↔ KBr + H₂O
In an acid-base reaction, an acid reacts with a base to form a salt and water. In option a, HBr (hydrobromic acid) reacts with KOH (potassium hydroxide) to form KBr (potassium bromide) and H₂O (water). This reaction involves the transfer of a proton (H⁺) from the acid (HBr) to the base (KOH), resulting in the formation of a salt (KBr) and water (H₂O).
In options b, c, and d, the reactions involve the exchange of ions between different compounds, but they do not represent an acid-base reaction. Option b represents a double displacement reaction, options c and d represent precipitation reactions. Only option a represents an acid-base reaction as indicated by the presence of an acid and a base reacting to form a salt and water.
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Calculate the amount (in moles) of gas which occupies 250cm³ at STP
Answers
Answer:
0.01
Explanation:
volume of 22.4 L (22,400 ml) at s.t.p. 250 ml out of 22,400 ml is 0.01 rounded, therefore I assume that is the answer. About 0.01 mole occupies 250 cm3 at s.t.p.
Give three examples of environmental, industrial and bio-chemistry.
Answers
Three examples of environmental, industrial and bio-chemistry are listed below:
Environmental chemistry: Contamination, Atmospheric Deposition, and Soil Pollution.industrial chemistry: industrial inorganic chemicals, industrial organic chemicals, and agricultural chemicalsbio-chemistry: genetic, immunology, and enzymologyMeaning of ChemistryChemistry can be defined as a branch of science which is concerned with the substances matter is composed of, their properties and reactions,
Chemistry also deals with the use of such reactions to form new substances.
In conclusion, Three examples of environmental, industrial and bio-chemistry are listed anove
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Question 23 (5 points)
What is the wavelength of radiation having a frequency of 4.80 x 1017 s-12
C = av
c= speed of light (3.00 x 108 ms-?)
X = wavelength in meters (m)
V = frequency = waves per second(s)
Show formula set up (2 pt)
Show calculator answer (1pt)
Show correct answer to the correct place with correct units (1 pt)
Use table 3 in data booklet to identify the type of radiation (1 pt)
Answers
Answer:
λ = 6.25 × 10⁻¹⁰ m
x-ray
General Formulas and Concepts:
Speed of Light = Wavelength times Frequency
c = λνExplanation:
Step 1: Define
C = 3.0 × 10⁸ m/s
ν = 4.80 × 10¹⁷ Hz (s⁻¹)
λ = unknown
Step 2: Solve for wavelength
3.0 × 10⁸ m/s = λ(4.80 × 10¹⁷ Hz)
λ = 6.25 × 10⁻¹⁰ m
Step 3: Check
We are given 3 sig figs. Follow sig fig rules.
6.25 has 3 sig figs. No changes necessary.
Step 4: Identify
6.25 × 10⁻¹⁰ m is in the x-ray spectrum according the the Electromagnetic Spectrum
PLS HELP ASAP PLSSSS
Answers
An element reacts with oxygen to give a compound with a high melting point. This compound is also
soluble in water. Name the element.
Answers
Answer:
Thus, we can say that the element is calcium. This can be clearly understood as ionic compounds have high melting and boiling points in general such as calcium oxide.
Answer:
The element is Calcium I guess.
Explanation:
Cause calcium oxide has high melting point and is soluble in water.