Scientists discover remains of wooden structures near a Celtic runes site. What kind of testing will indicate when the stones were moved into place by the Celts?
Carbon dating
Radioactive dating
Answer:
Carbon
Explanation:
Bc i got this question on my test
Answer:
A. Carbon dating
Explanation:
I took the test proof
How many grams of copper (II) hydroxide can be prepared from 2.4 grams of copper (II) nitrate (Cu(NO3)2 ) and excess sodium hydroxide?
Answer:
percentage yield = 67%
Explanation:
Mass of Cu(NO₃)₂ = 15.25 g
Mass of NaOH = 12.75 g
Percentage yield = ?
Solution:
Cu(NO₃)₂ + 2NaOH → Cu(OH)₂ + 2NaNO₃
Moles of Cu(NO₃)₂:
Number of moles = mass/ molar mass
Number of moles = 15.25 g /187.56 g/mol
Number of moles = 0.08 mol
Moles of NaOH :
Number of moles = mass/ molar mass
Number of moles = 12.75 g / 40 g/mol
Number of moles = 0.32 mol
Now we will compare the moles of Cu(OH)₂ with NaOH and Cu(NO₃)₂. NaOH : Cu(OH)₂
2 : 1
0.32 : 1/2×0.32 = 0.16 mol
Cu(NO₃)₂ : Cu(OH)₂
1 : 1
0.08 : 0.08
The number of moles produced by Cu(NO₃)₂ are less so it will limiting reactant.
Mass of Cu(OH)₂:
Mass = number of moles × molar mass
Mass = 0.08 mol × 97.6 g/mol
Mass = 7.808 g
Theoretical yield = 7.808 g
Percent yield:
percentage yield = Actual yield/ theoretical yield × 100
percentage yield = 5.23 g/ 7.808 g × 100
percentage yield = 0.67 × 100
percentage yield = 67%
1.3 grams of copper (II) hydroxide can be prepared from 2.4 grams of copper (II) nitrate (Cu(NO₃)₂) and excess sodium hydroxide.
Let's consider the following balanced double displacement reaction.
Cu(NO₃)₂ + 2 NaOH ⇒ Cu(OH)₂ + 2 NaNO₃
2.4 g of Cu(NO₃)₂ (molar mass 187.56 g/mol) react. The reacting moles of Cu(NO₃)₂ are:
[tex]2.4 g \times \frac{1mol}{187.56g} = 0.013 mol[/tex]
The molar ratio of Cu(NO₃)₂ to Cu(OH)₂ is 1:1. The moles of Cu(OH)₂ produced from 0.013 moles of Cu(OH)₂ are:
[tex]0.013molCu(NO_3)_2 \times \frac{1molCu(OH)_2}{1molCu(NO_3)_2} = 0.013 molCu(OH)_2[/tex]
The molar mass of Cu(OH)₂ is 97.56 g/mol. The mass corresponding to 0.013 moles of Cu(OH)₂ is:
[tex]0.013 mol \times \frac{97.56g}{mol} = 1.3 g[/tex]
1.3 grams of copper (II) hydroxide can be prepared from 2.4 grams of copper (II) nitrate (Cu(NO₃)₂) and excess sodium hydroxide.
You can learn more about stoichiometry here: https://brainly.com/question/22288091
Which is NOT an agent of chemical weathering?
A. water
C. carbon dioxide
B. oxygen
D. wind
Answer:
water is a water, but is also known as water. water means water, and the synonym of water is water, and antonym of water is non-water. water is located in earth. water's friends are pure water, salt water, dirty water and ice water. water's best friend is pure water, because when water gives water to pure water, pure water uses the water and gives back the water to the water.
thank you for enjoying my story
Explanation:
9.
Which of the following molecules has (have) polar bonds?
a water
b carbon dioxide
c formaldehyde
d two of the above
Answer:
two of the above
Explanation:
cK-12 Bond Polarity
Just wanted to know what the response time is :)
Which best describs the energy transformation in a battery powered flash light ?
a
Chemical, to electrical, to thermal, to radiant
b
nuclear, to electrical, to thermal, to radiant
c
Mechanical, to electrical, to Thermal, to radiant
d
Chemical, to electrical, to mechanical, to radiant
Answer:
I think it's C
Explanation:
Sorry if its wrong
Answer:
C
Explanation:
What is a goal of environmentalists? O A. Conservation of the environment O B. Protection of the environment O C. Public awareness of the environment O D. All of the above
Answer:
B?\
Explanation:
A goal of environmentalists is the protection of the environment.
What is an environment?The biotic and abiotic factors which surrounds living organisms are known as environment. To put it in simple word, it is a community of organisms living in a particular environment and the physical elements in that environment with which they interact.What is the role of environmentalists?Environmentalist preserve the air and water; as well as conserve and protect entire ecosystems compromising of animals, plants and humans found in different habitats throughout our planet.
Environmentalists help the public make informed decisions about the use of limited natural resources. They do research, produce reports, write articles, campaign etc.
Hence, option b is the correct answer.
To learn more about environment and environmentalists here
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How many days will it take for 80 grams of Iodine-131 to decay to 5 grams?
32 days
Further explanationGeneral formulas used in decay:
[tex]\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{t/t\frac{1}{2} }}}[/tex]
t = duration of decay
t 1/2 = half-life
N₀ = the number of initial radioactive atoms
Nt = the number of radioactive atoms left after decaying during T time
The half-life of iodine-131 is 8 days
No=80 g
Nt=5 g
[tex]\tt 5=80(\dfrac{1}{2})^{t/8}\\\\\dfrac{5}{80}=\dfrac{1}{2}^{t/8}\\\\\dfrac{1}{2}^4=\dfrac{1}{2}^{t/8}\\\\4=\dfrac{t}{8}\rightarrow 32~days[/tex]
I WILL GIVE YOU A BRAINLIEST: Bryce observes that the sun always seems to rise in the east. He talks with others and finds that everyone has the same observation. Which term describes this equation? A) the sun rises in the east B) Why does the sunrise in the east? C) The sun appears in the east because of Earth’s rotation pattern. D) If the sun appears in the east, then I am in the Western Hemisphere.
Answer: C
Explanation:
No matter the location on Earth, the sun always rises in the east due to its rotation pattern.
THIS QUESTION IS HARD BUT I NEED HELP AND ITS DUE IN 20 MINS. YOU HAVE TO ANSWER A AND B FOR EVERYTHING TO BE CORRECT. I KNOW YALL ARE SMART PLSS HELP. THANKS!!
Consider the two electron arrangements for neutral atoms A and B. What is the atomic number of A?
A - 1s?, 2s 2p6,35
B - 1s2, 2s 2p, 5s
0.954 mol bromine is added to 1 L reaction vessel that contains 1.22 mole of hydrogen and 1 mole of HBr at 1500K. What is the partial pressure of hydrogen, bromine and HBr at equilibrium?
Answer:
Partial pressure of H₂ → 149.9 atm
Partial pressure of Br₂ → 117.2 atm
Partial pressure of HBr → 112.8 atm
Explanation:
The problem can be solved by the Ideal Gases Law.
In a mixture of gases we know that the sum of partial pressures values the total pressure in the vessel. And the total pressure in the vessel is generated by the total moles which are presennt.
Total moles = 0.954 moles + 1.22 moles + 1 mol = 3.174 moles
Let's apply the Law to determine the total pressure.
P . 1 L = 3.174 moles . 0.082 . 1500 K
P = 390.4 atm
Now we apply the mole fraction concept
Mole fraction (1) → moles of gas / total moles
Mole fraction (2) → partial pressure of gas / total pressure
In conclussion 1 = 2
Partial pressure of H₂ → (1.22 / 3.174) . 390.4 atm = 149.9 atm
Partial pressure of Br₂ → (0.954 / 3.174) . 390.4 atm = 117.2 atm
Partial pressure of HBr → (1 / 3.174) . 390.4 atm = 112.8 atm
please help me out I need some ideas for cell city project or comic strip by tonight or if you did it already lemme copy it={
Answer:
Can you give me your snap, so I can send you the foto
[H3O+] = 2.6 x 10-3 M calculate OH
Answer:
3.85E-12
Explanation:
from
KW=[H3O+]×[OH]
BUT KW=1E-14
Consider the following equilibrium.
NH3(aq) + H2O(l) equilibrium reaction arrow NH4+(aq) + OH −(aq)
What will happen to the equilibrium constant if the concentration of OH − increases through the addition of a small amount of NaOH(aq)?
Answer:
It will remain the same
Explanation:
The equilibrium constant of the reaction will remain the same if the concentration of the OH is increased.
Changes in concentration values of any of the reactant does not affect the value of the equilibrium constant.
The equilibrium constant is a constant at a given temperature. It is temperature dependent. Since we have no change in temperature, therefore, the equilibrium constant will not change.The equilibrium constant if the concentration of OH − increases through the addition of a small amount of NaOH(aq) is :
- Remains same.
Equilibrium ReactionThe equilibrium constant of the response will stay the same in case the concentration of the OH is increased.
Changes in concentration values of any of the reactant does not influence the esteem of the equilibrium constant.
The equilibrium constant may be a consistent at a given temperature.
It is temperature dependent. Since we have no alter in temperature.Learn more about "Equilibrium":
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J.J. Thomson's plum pudding model of the atom followed the discovery of
A)
negatively charged particles with a very small mass.
B)
positively charged particles with a very large mass.
0)
negative electrons that revolved around a positive nucleus.
D)
positively charged protons that were contained in a concentrated area.
J.J. Thomson's plum pudding model of the atom followed the discovery of negatively charged particles with a very small mass. Thus, the correct option for this question is A.
Who was J. J. Thomson?J.J. Thomson was a British physicist who discovered sub-atomic particles known as electrons within an atom. He also announced that atoms are made up of smaller components.
The plum pudding model is defined by Thomson in order to demonstrate that negatively charged sub-atomic particles known as electrons are surrounded by a volume of positively charged particles known as protons. It is one of the historical scientific model of the atom that governs all sorts of properties of sub-atomic particles.
Therefore, "negatively charged particles with a very small mass" is the discovery that follows J.J. Thomson's plum pudding model of the atom. Thus, the correct option for this question is A.
To learn more about the Plum pudding model, refer to the link:
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Need help!!
A sample of water is currently boiling. What phase(s) is/are present?
gas
Liquid
solid
Answer:
a
Explanation:
What happens to the gravitational potential energy of an object if you bring it higher with respect to the ground? *
Answer:
Increases
Explanation:
The gravitational potential energy of an object increases as you bring it higher with respect to the ground.
Gravitational potential energy depends on the mass, height and gravity between two bodies;
Gravitational potential energy = mgh
m is the mass
g is the height
h is the height
We can clearly see that the higher the elevation, the more the value of the gravitational potential energy.What is the pH of a solution with a concentration of 1.0 * 10-4 M?
Answer: pH = 10
Explanation: First solve for pOH using the equation pOH=-log[OH-] = 4
Then plug the pOH in the equation, pH + pOH =14
then solve for pH. pH =14 - 4 = 10
Answer:
pH= 10
Explanation:
The pH really depends on what your solution is.
For example, if we are assuming that the concentration of 1.0M is of a strong monoprotic acid e.g. HCl, it would be safe to assume that almost all of the 1.0M acid has dissociated into its H+ ion, and its conjugate base. Thus, the pH can be determined by taking the negative log(to base 10), of the concentration.
Inversely, if the solution is of a strong base, the pOH value would be found, assuming the steps above. This pOH value can be used to infer a pH from the formula - pH + pOH = 14 then 14 - 4 = 10
Finally, come the weak acids/bases, which follow the rules above, except as they only partially dissociate, one needs its equilibrium constant to determine its extent of ionisation, to substitute into the negative log. This also is the case for the second, and higher order dissociation of polyprotic acids e.g. H2SO4.the answer is 10
Hope it helps
Please help it’s due in 30 minutes
Answer:
52.2. The large chicken egg minus the human head is 52.2 g. The egg is not a good model because it does not resemble a human head. Also, the egg is made of parts such as food and things that are not similar to a human head. Furthermore, they are not the same shape.
Explanation:
WILL MARK BRAINLIEST:
Identify the dichotomous key: plz answer:::: Each of these aliens belongs to the same genus. What is their genus?
Answer:
Alienus
Explanation:
what do seismic waves do
Answer:
Seismic waves are the waves of energy caused by the sudden breaking of rock within the earth or an explosion. They are the energy that travels through the earth and is recorded on seismographs. ... Earthquakes radiate seismic energy as both body and surface waves.
Answer:
they are caused from earthquakes
Explanation:
Earthquakes and underground explosions can release a lot of energy. That energy ripples away from its source in a variety of ways. Some of those vibrations will move forward and back through the material they travel through . Other waves travel just like ocean waves, where they make the material they pass through move up and down compared to the direction the wave is traveling. And while some of these waves travel deep within the planet, still others move only along the surface. Studying where these various flavors of waves are and how they move not only can help scientists pinpoint where an earthquake or explosion occurred, but also can shed light on the structure of our inner planet.
What is the characteristic of all ions
Answer:
They have one overall charge
Explanation:
Negative or positive
A bicycle has a momentum of 25.00 kg x m/s and a velocity of 2.5 m/s. What is the bicycle’s mass
Answer:
10 kgExplanation:
The mass of the bicycle can be found by using the formula
[tex]m = \frac{p}{v} \\ [/tex]
p is the momentum
v is the velocity
From the question we have
[tex]m = \frac{25}{2.5} \\ [/tex]
We have the final answer as
10 kgHope this helps you
What happens when the particles of a gas collide?
A. They vibrate in place
B. They stick to one another
C. They become particles of a solid
D. They bounce off one another
Answer:
A
Explanation:
identify the statement that accurately describes ATP
Answer:
Adenosine triphosphate
In science, ATP stands for adenosine triphosphate. This chemical, discovered in the 1920s, is important to all life. It stores and releases energy for many cellular processes. It is found in mitochondria.
Explanation:
How many electrons are in the outermost shell of the K+ ion in its ground state?
Answer:
19 electrons
Explanation:
Is the chemical equation balanced?
Zn + 2HCl → ZnCl2 + H2
no, or yes
Answer:
Yes.
General Formulas and Concepts:
Chemistry - Stoichiometry
Balancing reactionsReaction predictionExplanation:
Step 1: RxN
Zn + HCl → ZnCl₂ + H₂
Step 2: Balance RxN
Zn + 2HCl → ZnCl₂ + H₂
Need 2 H's on both sidesNeed equal amount of Cl's on both sidesIs calcium oxide a Element or compound or mixture?
Answer:
compound
Explanation:
Answer:
The answer is compound
Explanation:
Rank the following in order from the lowest to highest ionization energy?
Bi, Cs, Ba
Answer:
Cs,Ba, Bi
Explanation:
Ionization energy increases across the period from left to right on the periodic table
