Explanation:
the. correct option is d
a sample of wood that originally contained 100 grams of carbon14 now contains only 25 grams of carbon 14. approximately how many years ago was this sample part of a living tree
11460 years ago a sample of wood was the part of a living tree.
What is half-life?The time required for half of something to undergo a process.
Carbon-14 has a half-life of 5,730 years. That means that no matter how many carbon-14 atoms were present when something died, after 5,730 years only half of them are left the rest have decayed to nitrogen.
The half life of C-14 is [tex]t_{\frac{1}{2}}[/tex] =5730 years.
This means that if you start with a sample of 100g, only 50g will be left in 5730 years.
Here, Only 25g is left, therefore the number of years is =5730 × 2 = 11460years.
Hence, 11460 years ago a sample of wood was the part of a living tree.
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How dose earths solid inner core affect seismic waves
Answer:
When seismic waves from earthquakes ripple through its solid center, they hit a speed bump. The seismic vibrations should zip along about 30 percent faster than their actual speed, according to experiments and computer models re-creating the conditions inside the inner core.
What volume of 12M HCI is needed to prepare 250
of 0.20M HCI?
Answer: 4.2
Explanation:
[tex]M_{A}V_{A}=M_{B}V_{B}\\(12)V_{A}=(250)(0.20)\\V_{A}=\frac{(250)(0.20)}{12}=\boxed{4.2}[/tex]
Determine the mass of hydrogen gas collected in a container if the gas occupies
44.8 L at STP.
Answer:
Hope this helps kinda got confused mid way
Explanation:
So the hydrogen sulphide is H2S for the molecular formula. Then the mass of hydrogen sulphide would be 1×2+32= 34g/mol At STP.
What does each star on the map represent?
O location of an epicenter
O location of a focus
O location of a seismograph
O location of a wave
Each star on the map represents location of an epicenter. Thus, the correct answer is Option A.
What is an epicentre on the map?Epicenter is defined as the point directly at the position on the Earth's surface, where the earthquake started. These are represented by the stars on the map.
Scientists use triangulation to find the epicenter of an earthquake.
When seismic data is collected from at least three different locations, it can be used to determine the epicenter by where it intersects.
Every earthquake is recorded on numerous seismographs located in different directions.
Thus, the correct answer is Option A.
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Answer: C. location of a seismograph
Explanation:
What is the pH of a solution with a pOH of 10?
The pH of the solution is 4.
What is pH value ?pH value is the measure of the acidity and basicity of a solution.
It measures the [H+] ion liberated by an acid when dissolved in a solution.
It has a range of 0 to 14 , where 0 to 6.9 indicates acidity , 7 represents neutral solution , More than 7 up to 14 indicates alkaline solutions.
pH value is also used to predict the completion of a reaction .
It is given in the question that
The value of pOH = 10
pH = ?
It is known that the sum of pH and pOH is equal to 14.
pH + pOH = 14
pH + 10 = 14
pH = 4
Therefore the pH of the solution is 4.
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Use the reaction and bond information to answer the question. H2 CO2 → CH2O2 Reactant bond energies: H–H is 432 kJ/mol, C=O is 799 kJ/mol Product bond energies: C–H is 413 kJ/mol, C=O is 745 kJ/mol, C–O is 358 kJ/mol, O–H is 467 kJ/mol How much energy must this system absorb before the reaction can begin?.
345678990098765435779999999999999999995699999
Calculate the solubility of Ca(OH)2 in a 0.469M CaCl2 solution at 31°C, given that the Ksp of Ca(OH)2 is 4.96 x 10-6 at that temperature. Give your answer in milliMolar units 2.927 mM 1.626 mM 2.764 mM 1.382 mM 1.463 mM 3.252 mM
The solubility of Ca(OH)2 in a 0.469M CaCl2 solution at 31°C, at given Ksp of Ca(OH)2 is determined as 1.626 mM.
Dissociation reaction of Ca(OH)2
The dissociation reaction of Ca(OH)2 is given as follows;
Ca(OH)₂ ⇄ Ca²⁺ + 2OH⁻¹
x 2x
Concentration of Ca²⁺ = 0.469 M
Ksp = [x][2x]²
ksp = (0.469)(2x²)
ksp = 4(0.469)x²
ksp = 1.876x²
4.96 x 10⁻⁶ = 1.876x²
x² = (4.96 x 10⁻⁶)/(1.876)
x² = 2.643 x 10⁻⁶
x = √(2.643 x 10⁻⁶)
x = 1.626 x 10⁻³ M
x = 1.626 mM
Thus, the solubility of Ca(OH)2 in a 0.469M CaCl2 solution at 31°C, at given Ksp of Ca(OH)2 is determined as 1.626 mM.
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when we send electricity to pass through electrolysis jar we see gas bubble around both electrodes. Water electrolysis produces 46cm3 at anode.
A). What gas does it appear at each electrode?
B). What would you do to identify the gas in the test tubes at each electrode?
C). Calculate the volume of gas which appears at cathode.
A) Anode - hydrogen gas
Cathode-oxygen gas
B) Hydrogen gas - The gas burns with a pop sound
Oxygen gas - The gas rekindles a glowing splint
C) The volume of gas produced at the cathode is 23 [tex]cm^3[/tex]
What is electrolysis?Electrolysis is the process by which electric current is passed through a substance to effect a chemical change.
The electrolysis of water produces two volumes of hydrogen at the anode and one volume of oxygen at the cathode.
The hydrogen gas burns with a pop sound. It is easily identified by this test. Also, oxygen is known to rekindle a glowing splint and this is a commonly used test for oxygen gas.
Since the ratio of hydrogen produced at the anode to oxygen produced at the cathode is 2:1 by volume; then when 23 [tex]cm^3[/tex] of oxygen is produced at the cathode, 46 [tex]cm^3[/tex]of hydrogen is produced at the anode.
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A container holds a mixture of 3.01 x 1023 molecules of H₂ gas. 1.20 x 1024 molecules of CO₂ gas, and 1.50 x 10
24 molecules O₂. If the total pressure of the container is 1.00atm, what is the partial pressure of oxygen gas in
atmospheres?
O 5.00 x 10 ¹ atm
O 9.09 x 10-2 atm
O2.50 x 10 ¹ atm
O2.00 x 10-¹ atm
8 9
10 11
12 13 14
15 16 1
Answer:
.4998 atm ( rounded to .5 atm ) <===== not one of the answers listed
Explanation:
The partial pressure exerted by O2 is equal to the fraction that is O2 times the pressure
1.5 / ( 1.5 + 1.2 + .301 ) * 1 atm = .4998 atm
( 1) Are you sure it is ONE atm pressure in the container?
(2) IS the first answer supposed to be 5 x 10^-1 atm perhaps?
The bright coloring of the skin of this poison dart frog announces, "Don't eat me! My
skin is poisonous."
This is an example of an adaptation that meets the challenge of...
maintaining structure
reproduction.
getting and using energy
What is specific heat capacity?
If answer is correct I will mark as brainliest
Answer:
A. The energy required to completely melt 1 g of a substance.
Explanation:
Because the root definition for Specific Heat Capacity is basically the amount of heat that's absorbed per unit mass of whatever material when the temperature is increasing. Or in other words, the amount of heat that's taken out or supplied to the unit mass of a system in order to increase or decrease its temperature by one degree. Hope this helps :)
Given that this reaction is exothermic, what direction will the equilibrium shift when the temperature of the reaction is decreased? 3H₂(g) + N₂(g) ⇔ 2NH₃(g)
A. Left (towards the reactants)
B. Right (towards the products)
C. No Shift
Equilibrium will shift towards the products when temperature is decreased in an exothermic reaction of the formation of ammonia.
What is an exothermic reaction?An exothermic reaction is a reaction in which heat content of the reactants is greater than the heat content of product.
In an exothermic reaction, heat is given off.
For an exothermic reaction in equilibrium, increasing temperature shifts equilibrium to the towards the left, towards the reactants.
On the other, equilibrium will shift towards the products when temperature is decreased.
Therefore, equilibrium will shift towards the products when temperature is decreased in the reaction of the formation of ammonia.
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Do taller people have longer arms that shorter people? Find the dependent variable, independent variable and state your hypothesis. PLS HELP
Answer:
A hypothesis is a testable statement that is proposed to explain an observation/theory. In this case, one hypothesis that could be used is: Taller people have longer arms than smaller people. You could also say: As the height of an individual increases, the length of their arms also increases.
Independent variables are the variable that is manipulated. In this case, the independent variable is the height of the individual.
Dependent variables are those that change in response to the independent variable. In this case, the dependent variable is arm length.
A The weak base ionization constant (Kb) for CH3NH2 is equal to: B [CH3NH3+][OH-] [CH3NH₂] [CH3NH3 +][OH [CH3NH2][N2 O]
The weak base ionization constant (Kb) for [tex]CH_3NH_2[/tex] is equal to
[tex]Kb = [CH_3NH^{3+}] [OH^-] / [CH_3NH_2][/tex]
What is Kb?Kb is the base dissociation constant.
The expression for the equilibrium constant, Kb is simply the ratio of the concentration of the products raised to their coefficient to the concentration of the reactants raised to their coefficient.
[tex]CH_3NH_2(aq) + H_2O(l)[/tex] → [tex]CH_3NH^{3+}(aq) + OH^- (aq)[/tex]
Thus, the expression for the equilibrium constant, Kb fo the above reaction can be written as follow:
[tex]Kb = [CH_3NH^{3+}] [OH^-] / [CH_3NH_2][/tex]
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PLEASE HELP!!!!!!!
In an experiment, the molar mass of the compound was determined to be 118.084 g/mol. What is the molecular formula of the compound?
Succinic acid most probably
C_4H_6O_4Lets see why?
The molar mass is given as 118.084g/mol
Decimal next place i.e 10th place contains 0 means it has OH bonds in most of the cases.
So it's a hydrocarbon and more closely an alcohol or aldehyde
Let's verify
4(12)+6(1)+16(4)64+48+670+58118g/molApproximately equal
What is the heat of reaction into kJ?
H₂(g)+Br₂(g)➝2HBr(g)
see the attached file!!!
What is the equilibrium constant of a reaction?
A. It is the concentrations of products multiplied by the
concentrations of reactants.
о
B. It is the number of moles of reactants subtracted from the number
of moles of products.
C. It is the ratio of the concentrations of products to the
concentrations of reactants.
D. It is the ratio of the number of moles of products to the number of
moles of reactants.
Answer:
C. It is the ratio of the concentrations of products to the
concentrations of reactants.
Explanation:
How is graphite structured?
A. Its carbon atoms are bonded to 3 other carbon atoms and are
structured in layers that can slip past each other.
B. Its carbon atoms are bonded to 3 other carbon atoms and are
structured in layers that cannot slip past each other.
C. Each carbon atom is surrounded entirely by lone pairs, which
is why the carbon atoms separate from each other to the paper
easily when writing.
D. Each carbon is bonded to four others making it very solid and
rigid.
Graphite is structured in a way that: (A). Its carbon atoms are bonded to 3 other carbon atoms and are structured in layers that can slip past each other.
Meaning of a graphiteA graphite can be defined as a crystalline form of carbon.
Graphite is so important to man as it is used in many industries and factories as well as many countries to produce different products that can help mankind.
Graphite structure is quite a complex one and it involve carbons that have three of its electrons bonded and one free.
In conclusion, Graphite is structured in a way that: Its carbon atoms are bonded to 3 other carbon atoms and are structured in layers that can slip past each other.
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Based on the following reaction, how much water is produced when oxygen react with 1 mole of C₂H8?
C₂H8 (g) + 40₂ (g) →2CO2 (g) + 4H₂O(g)
Answer:
4 moles
Explanation:
For every mole of deuteriomethane consumed, 4 moles of water are produced.
So, the answer is 4 moles.
What is the pH of a solution that contains 0.0011 moles of KOH in 393 mL of solution?
The pH of a solution that contains 0.0011 moles of KOH in 393 mL of solution is 2.56. Details about pH can be found below.
How to calculate pH?The pH of a solution can be calculated using the following expression:
pH = - log [H3O+]
However, the hydrogen concentration of the KOH solution can be calculated as follows:
concentration = 0.0011 mol ÷ 0.393 L
concentration = 2.798 × 10-³M
The pH of KOH = - log [2.798 × 10-³M]
pH = 2.56
Therefore, the pH of a solution that contains 0.0011 moles of KOH in 393 mL of solution is 2.56.
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when energy is transferred does it increase or decrease
Answer:
About energy transfers:
Explanation:
When there is an energy transfer energy is neither created, nor destroyed. This means when that when one energy store decreases, one or more others must increase.
Which of the following items represents a chemical change?
melting
evaporation
freezing
burning
A 47-year-old man with a history of alcoholism is brought to the emergency department because he was found wandering in the streets. He appears disoriented and walks unsteadily. Physical examination shows an inability to adduct the right eye or to abduct the left eye. When asked about recent events that may have resulted in his condition, he responds with several elaborate but obviously fictitious stories. Altered activity of which of the following enzymes is most likely contributing to his symptoms?
The altered activity of the Pyruvate dehydrogenase enzyme is most likely contributing to his symptoms.
What is Pyruvate dehydrogenase?Pyruvate dehydrogenase is an enzyme that catalyzes the conversion of pyruvate to generate dihydrolipoamide and CO2.
This enzyme (Pyruvate dehydrogenase) is required to metabolize alcohol present in the blood.
In conclusion, the altered activity of the Pyruvate dehydrogenase enzyme is most likely contributing to his symptoms.
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Why we use cotton cloth to mop the floor?
Answer:
because cotton have a good absorbing quality and can absorb water more which is used to mop the floor
Explanation:
Can anyone please help me, the attachment is down below
Bubbling or fizzing is usually observed when a chemical reaction occurs and is denoted as option D.
What is a Chemical reaction?This occurs when one or more reactant form a new substance which is referred to as the product.
The bubbling or fizzing depicts effervescence which signifies that a new gaseous product has been formed.
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The number of moles of Cr deposited by passing 1,5 F electricity in following reaction Cr+3e–– ›cr is
The number of moles of Cr deposited by 1.5 F of electricity is 0.5 moles
What is electrolysis?The term electrolysis has to do with thee deposition of a solid when a direct current is passed through its solution.
Given the reaction; Cr3+(aq) + 3e ––›Cr(s)
If 3F of electricity is required to deposit 1 mole of Cr
1.5F of electricity is required to deposit 1.5F * 1 mole/3F
= 0.5 moles
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Which of these is NOT true about electromagnets?
They are permanent.
Increasing the battery makes them stronger.
They need a battery or other source of current.
Increasing the number of coils makes them stronger.
Answer:
Permanent = false
Explanation:
All of the other choices are true
Write the complete chemical equations for production of pentanol from pentene
Answer:
hope this helped :( got this from my friend a long time ago but still not sure if it's really correct this
For the reaction
2A(g)+2B(g)+C(g)⟶3G(g)+4F(g)
the initial rate data in the table was collected, where [A]0 , [B]0 , and [C]0 are the initial concentrations of A , B , and C , respectively.
Experiment [A]0 (mmol⋅L−1) [B]0 (mmol⋅L−1) [C]0 (mmol⋅L−1) Initial rate (mmol⋅L−1⋅s−1)
1 11.0. 200.0 220.0 8.80
2 22.0 200.0 165.0 17.6
3 22.0 400.0 55.0 70.4
4 11.0 200.0 110.0 8.80
Reactant A is first order reactant, Reactant B is second order reactant, and Reactant C is zero order reactant...
1. What is the overall order of the reaction ______ ???
2. Write the rate law for the reaction where is the rate constant. Rate = k___???
3. Calculate the rate constant, , and identify its units. K = ____?????
4. Determine the initial rate of the reaction when [A]0=4.87 mmol⋅L−1 , [B]0=0.184 mmol⋅L−1 , and [C]0=12.0 mmol⋅L−1 . Initial Rate = _______ mmol⋅L−1⋅s−1 ??????
The overall order of the reaction is 3 and the rate law for the reaction is rate = [A]^n [B]^m [C]^l
How to find the Order of Reaction?
1) The order of reactant A is first order reactant because a first-order reaction can be defined as a chemical reaction in which the reaction rate is linearly dependent on the concentration of only one reactant.
The order of reactant B is second order reactant because a second order reaction is a type of chemical reaction that depends on the concentrations of one-second order reactant or two first-order reactants.
Thus, the overall order of the reaction is 3.
2) The rate law in this reaction is;
rate = [A]^n [B]^m [C]^l
But in this question, since the reactant C is zero order, then it will be simplified to; rate = k[A][B]² .
3) When we plug in the initial concentrations of A and B, we will get the rate constant of the problem which is k = 20.
4) The initial rate when [A]0=4.87 mmol⋅L−1 , [B]0=0.184 mmol⋅L−1 , and [C]0=12.0 mmol⋅L−1 is;
Rate = 20 * 4.87 * 0.184²
Rate = 3.3
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