Why would scientists use a control sample that is known to be from a
specific species in an eDNA surveillance for that species?
A. So they can have a negative control against samples
B. So they can cut sample DNA into fragments
C. So they can amplify the DNA in small samples
D. So they can identify samples that contain the target DNA
Answer:
Here is the answer...
Explanation:
Option A is used to control sample that is known to be form.
A chemistry journal requires that all new research papers be peer reviewed by other scientists before they are published. This
allows which of the following?
The reviewers can determine the experiment's feasibility
The reviewers can determine the experiment's validity
The reviewers can include their own findings with the research.
The reviewers can determine if they will help fund the research.
Answer:
I think its number 2
Explanation:
Please Help Me!!
1. What does the expression “metals eating each other” as used by the electrician refer to? Explain and give an example.
2. What are the possible electrolytes in the rusted panel?
3. Using the table for electrode potential differences (Figure 2) identify the possible composition of the screws responsible for the corrosion observed in the contact area with the copper wire.
Answer:
1. Galvanic oxidation. Example is the corrosion of aluminium wires when in contact with copper wires under wet conditions.
2. Rainwater or Damp/moist air
3. Chromium-plated steel screws or stainless steel screws or galvanized steel screws
Explanation:
1. Galvanic oxidation or corrosion occurs when two different metals with different electrode potentials are brought into contact with each other by means of an electrolyte (usually a aqueous solution), such that a redox reaction occurs leading to one metal with the more negative electrode potential (the anode) becoming oxidized, while the other less negative potential (the cathode) is reduced.
In order for galvanic corrosion to occur, three elements are required.
i. Two metals with different corrosion potentials (anode and cathode)
ii. Direct metal-to-metal electrical contact
iii. A conductive electrolyte solution (e.g. water) must connect the two metals on a regular basis.
For example oxidation (corrosion) of aluminium wires when in contact with copper wire under wet conditions.
2. The most likely electrolyte will be rainwater containing dissoved solutes (if the panel is in an exposed part of the house) or damp/moist air.
3. From the table, the most likely screw will be chromium-plated steel screws or stainless steel (made of iron and nickel) screws or galvanized steel (zinc-plated) screws.
All these possible screw components have a more negative electrode potential than copper. Thus they will serve as the anode in a galvanic oxidation with copper.
Three examples of chemical reactions ????? PLEASE HELP
Answer:
Photosynthesis, Respiration, Combustion, Anaerobic Respiration
Explanation:
Im not 100% sure if this is what you are looking for but it should be correct. Hope this helps! :)
What do you need in order to do a stoichiometric calculation? (Choose
multiple)
Balanced Chemical Equation
Molar masses of compounds involved
The type of reaction taking place
Oxidation Numbers
In Universe L, recently discovered by an intrepid team of chemists who also happen to have studied interdimensional travel, quantum mechanics works just as it does in our universe, except that there are six d orbitals instead of the usual number we observe here.
Use these facts to write the ground-state electron configurations of the fifth and sixth elements in the first transition series in Universe L.
Note: you may use to stand for the electron configuration of the noble gas at the end of the row before the first transition series.
fifth transition metal:
sixth transition metal:
The electron configuration of the fifth and sixth transition elements in universe L may be slight different than as it is on earth.
The electron configuration shows the distribution of electrons in atoms. In atoms electrons are distributed in orbitals. Different orbitals hold different maximum number of electrons in them.
On earth, the d orbitals are five but in universe L, the d orbitals are six. This implies that d orbitals in universe L can hold a total of twelve electrons.
The fifth transition metal is Manganese. The electron configuration of manganese in universe L is [Ar] 3d6 4s1. The sixth transition element is iron. The electron configuration of iron in universe L is [Ar] 3d6 4s2.
Learn more: https://brainly.com/question/4147359
Which of the following is an example of acceleration? 88m/s, 15km/hr,14m/s East, 9.8 m/s^2 south
Answer: The answer is 9.8 m/s^2 south
Explanation:
It is expected that US forests will
Answer:
be able to meet long term timber needs.
Explanation:
Forest Services has been indicated for a long time the exhaustion of timer in the United States. However, in the recent decade, this trend has shown a reverse. The creation of nuclear energy and other technological developments that bring about drastic changes in our way of life. Gradually, the forest has recovered its trees and plants, and it is anticipated that timber will be available to meet long-term wood needs.
How many grams of aluminum would have the same number of atoms as 6.94 g of lithium?
Answer:
26.984g =Al cantain 1.6023x10^27amu
6.94=li cantain 1.6023x10^27amu
thus
mass of aluminium/mass of lithium
26.984/6.94=3.89
5. Which of the following is NOT a physical change?
nailing together boards of wood
breaking an egg
dying your hair
adding food coloring to water
Plants need sunlight, water, and minerals from the soil in order to grow and thrive. These factors
A.
are always abundant, allowing unlimited growth.
B.
limit the number of plant populations that can grow in an ecosystem.
C.
require human intervention to be replenished.
D.
prevent new plant populations from entering the ecosystem.
Answer:
B. limit the number of plant populations that can grow an ecosystem
Answer:
B. limit the number of plant populations that can grow in an ecosystem.
Explanation:
which of the following is larger then the atomic radius of phosphorus
Options
a: the ionic radius of phosphorus
b: the atomic radius of argon
c: the atomic radius of nitrogen
d: the ionic radius of chlorine
Answer:
a)the ionic radius of phosphorus
Explanation:
phosphorus=2.8.6
for phosphorus to become stable(2.8.8) it gains two electrons thus the ionic radious increases bcz of the gained electrons
Imagine designing an experiment in which the presence of a gas is determined by simply listening to the gas with your ear. The human ear can detect pressures as low as 2 x 10^-5 N*m^-2. Assuming that the eardrum has an area of roughly 1 mm^2, what is the minimum collisional rate that can be detected by ear? Assume that the gas of interest is N2 at 298 K.
Answer:
Explanation:
Pressure = Force/Area
so,
Force =Pressure x Area
Force =(2x 10⁻⁵ )N/M² x (1 x (10⁻³)² M²
Force = 2 x 10⁻¹¹N
as we know,
Force= mass x acceleration ( F=m.a)
a = F/m
a =(2 x 10⁻¹¹N)/28
g since 1 N=1.kg.m.s⁻²
a=(2 x 10-11kg.m.s⁻² )/(28 x 10⁻³kg)
a = 5.6 x 10-7 m.s⁻²
thus minimum collision rate that can be detected is 5.6 x 10-7 m.s⁻²I really need to pass chem, someone please help me! <3
a chemical reaction can be represented by
Answer:
A chemical reaction is a rearrangement of atoms which turn one or more compounds into new compounds. Equations and models may describe all of the chemical reactions. ... If atoms detach from each other and recombine into various types of atoms, we conclude that there has been a chemical reaction.
Answer:
equations and models.
Explanation:
All chemical reactions can be represented by equations and models.
A 2.7 M solution contains
0 2.7 moles of solute per 1000 g of solvent.
2.7 moles of solute per 1000 mL of solution.
0 2.7 grams of solute per 100 mL of solution.
0 2.7 grams of solute 100 g of solution.
per
Answer:
2.7 moles of solute per 1000 mL of solution.
Explanation:
Hello,
In this case, molarity is defined as the ratio of the moles of the solute to the volume of the solution in litres, thus, for a 2.7-M solution, it is clear that we have 2.7 moles of the solute in 1 L of solution, thus the option having the proper relation is 2.7 moles of solute per 1000 mL of solution as 1 L equals 1000 mL.
Best regards.
Sunlight Grass → Rabbit + Snake
What is the abiotic factor in this food chain?
Sunlight
Grass
Rabbit
Snake
Answer:
The abiotic factor is Sunlight.
what is the sex-ratio in rajasthan according to 2011 census?
Answer:
Sex ratio of India according 2011 census is 940 females per 1000 males. Sex ratio of Rajasthan is 928 which means there are 928 female present per 1000 males
Explanation:
pls check my answer brain list
A substance is followed by the symbol (1) in a chemical equation. What does the symbol represent?
Answer:
The symbol (l) stands for liquid phase.
Explanation:
1 point
A container with nitrogen, oxygen, and hydrogen has a pressure of 10.46
atm. If the pressure of nitrogen is 321 kPa and the pressure of oxygen is
74.0 psi, what is the pressure of hydrogen? *
2.25 atm
18.7 atm
4.90 atm
237 atm
Answer:
2.25 atm
Explanation:
Given data
Pressure of N₂: 321 kPaPressure of O₂: 74.0 psiPressure of H₂: ?Total pressure: 10.46 atmStep 1: Convert the pressure of nitrogen to atm
We will use the relationship 1 atm = 101.325 kPa.
[tex]321kPa \times \frac{1atm}{101.325kPa} = 3.17 atm[/tex]
Step 2: Convert the pressure of oxygen to atm
We will use the relationship 1 atm = 14.6959 psi.
[tex]74.0psi \times \frac{1atm}{14.6959psi} =5.04atm[/tex]
Step 3: Calculate the partial pressure of hydrogen
The total pressure is the sum of the partial pressures.
P = pN₂ + pO₂ + pH₂
pH₂ = P - pN₂ - pO₂
pH₂ = 10.46 atm - 3.17 atm - 5.04 atm
pH₂ = 2.25 atm
Answer:
[tex]P_H=2.25atm[/tex]
Explanation:
Hello,
IN this case, we can apply the Dalton's law in order to understand the pressure behavior of a mixture as the summation of all the pressures of the compounds in the mixture, in this case, nitrogen, oxygen and hydrogen:
[tex]P_T=P_O+P_N+P_H[/tex]
So, since we are asked to compute the pressure of hydrogen, we simply solve for it:
[tex]P_H=P_T-P_O-P_N=10.46atm-74.0psi*\frac{1atm}{14.6959psi} -321kPa*\frac{1atm}{101.325kPa} \\\\P_H=2.25atm[/tex]
Best regards.
One of the most desirable of the old British sports cars was the beautiful Triumph Vitesse (1963-1971). Pictured below is the American version, called the Sports 6. A little expensive back in the day, only 679 were sold. Imagine you are on vacation, and for fun you and your companion select a cool, beautiful day in Gansu Province and ride the G30 highway from Lanzhou to the Mogao caves in Dunhuang, about distance of 686 miles. If you consume gasoline according to:
2 C8H18(l) + 25 O2(g)? 16 CO2(g) + 18 H2O(g)what volume of carbon dioxide gas would be produced by this motoring trip if your fuel consumption was 21.2 miles per gallon? Note that the density of gasoline is 0.805g/cm3, and one mole of any gas at 760 mmHg and 0oC is 22.4 L.
Answer:
[tex]V_{CO_2}=1.55x10^{5}LCO_2=155m^3CO_2[/tex]
Explanation:
Hello,
In this case, given the reaction:
[tex]2 C_8H_{18}(l) + 25 O_2(g)\rightarrow 16 CO_2(g) + 18 H_2O(g)[/tex]
The total consumed gallons are computed by considering 686 miles were driven and the consumption is 21.2 miles per gallon, thus:
[tex]V_{C_8H_{18}}=686miles*\frac{1gal}{21.2miles} =32.4gal[/tex]
Hence, with the given density, one could compute the consumed grams and consequently moles of gasoline as well as moles that were consumed:
[tex]n_{C_8H_{18}}=32.4gal*\frac{3785.41cm^3}{1gal} *\frac{0.805g}{1cm^3} *\frac{1mol}{114g}=864.95mol C_8H_{18}[/tex]
Next, since gasoline (molar mass = 114 is in a 2:16 molar relationship with the yielded carbon dioxide, we compute its produced moles as shown below:
[tex]n_{CO_2}=864.95mol C_8H_{18}*\frac{16molCO_2}{2molC_8H_{18}} =6919.6molCO_2[/tex]
Finally, we could assume the given STP conditions to compute the volume of carbon dioxide, as no more information regarding the space wherein the carbon dioxide is available:
[tex]V_{CO_2}=\frac{n_{CO_2}RT}{P} =\frac{6919.6mol*0.082\frac{atm*L}{mol*K}*(0+273)K}{1atm} \\\\V_{CO_2}=1.55x10^{5}LCO_2=155m^3CO_2[/tex]
Best regards.
A proton is a hydrogen atom without its electron?
True
False
You are asked to analyze an aqueous solution (X) and determine what's in it. You pour some of your sample X into a test tube and add a few drops of an acid. No observable reaction occurs. Then you add a few drops of barium chloride solution to your mixture (containing an aqueous solution X and the acid), a white precipitate forms.
1. What can you conclude about the solution X, based on this experiment?
(Circle as many choices as applies.)
A. Solution X must contain a covalent (molecular) compound.
B. Solution X does not react with barium chloride.
C. This experiment is inconclusive, and does not provide any information about the contents of X.
D. Solution X must contain sulfate ion.
E. Solution X does not contains any ionic compound.
F. The solution X contains an ionic compound.
Answer:
b. Use an AD/AS diagram to show how a decrease in the inflation target can keep inflation and short-run output from starting to rise in 2021. Explain your diagram and what it reveals about monetary policy.
For the reaction 2H₂(g) + O₂(g) → 2H₂O(g), what volume of water vapor can be made from 100 grams of oxygen gas and an excess of hydrogen at STP? Please show work.
Answer:
140 L
Explanation:
Step 1: Write the balanced equation
2 H₂(g) + O₂(g) → 2 H₂O(g)
Step 2: Calculate the moles corresponding to 100 g of oxygen
The molar mass of oxygen is 32.00 g/mol.
[tex]100g \times \frac{1mol}{32.00g} =3.13mol[/tex]
Step 3: Calculate the moles of water vapor formed
The molar ratio of oxygen to water vapor is 1:2.
[tex]3.13molO_2 \times \frac{2molH_2O}{1molO_2} =6.26molH_2O[/tex]
Step 4: Calculate the volume corresponding to 6.26 moles of water vapor
1 mole of any ideal gas under STP has a volume of 22.4 L.
[tex]6.26mol \times \frac{22.4L}{mol} =140 L[/tex]
True or false. The kinetic energy of reactant particles has no effect on the reaction rate?
Answer:
false
Explanation:
What happens when you put magnesium carbonate and diluted water
Answer:
Magnesium carbonate doesn't dissolve in water, only acid, where it will effervesce (bubble).
Explanation:
An insoluble metal carbonate reacts with a dilute acid to form a soluble salt. Magnesium carbonate, a white solid, and dilute sulfuric acid react to produce magnesium sulfate. Colourless magnesium sulfate heptahydrate crystals are obtained from this solution.
At certain times during the process, the temperature increased. During these times, the heat that was absorbed took the form of energy in the water molecules. This process caused the molecules to .
At other times during the process, the temperature didn’t increase. During these times, the heat that was absorbed took the form of energy in the water molecules. This process caused the water molecules to .
Answer: kinetic, move faster, potential, change form
Explanation:
Answer: kinetic, move faster, potential, change state
Explanation: Edmentum
Circle the functional groups and I need help naming 7) and 10)
Answer:
The answer to your question is given below.
Explanation:
1. The functional group is alkanol or alcohol (R–OH).
2. The functional group is alkanone or ketone (RC=OR).
3. The functional group is alkanal or aldehyde (R–CHO)
4. The functional group is alkanoic or carboxylic acidic (R–COOH).
5. The functional group is ether (ROR)
6. The functional group is ester (RCOOR).
7. The functional group is alkanol or alcohol (R–OH).
8. The functional group is alkanoic or carboxylic acidic (R–COOH).
9. The functional group is alkanal or aldehyde (R–CHO).
10. The functional group is alkanone or ketone (RC=OR).
Naming of the compound
To name the above compound, we must do the following:
1. Locate the longest continuous carbon chain. This gives the parent name.
2. Identify the functional group.
3. Identify and locate the position of the substituent group attached if there are any.
4. Combine the above to obtain name of the compound.
Now, let us name compound 7 and 10.
7a. The longest carbon chain is 4 i.e butane.
b. The functional group is –OH i.e alkanol or alcohol. We'll replace the –e in butane with –ol to obtain the name.
Therefore, the name of the compound is butanol.
10a. The longest carbon chain is 4 i.e butane.
b. The functional group is RC=OR i.e alkanone or ketone. We'll replace the –e in butane with –one to obtain the name.
Therefore, the name of the compound is butanone.
Ultraviolet photoelectron spectroscopy (UPS) is an important analytical tool used to characterize the composition of materials in academic, industrial and national laboratories. The technique relies on the photoelectric effect where-in electrons are emitted from a material when it absorbs ultraviolet photons. Make a plot of the kinetic energy of the photo-emitted electrons versus the frequency of the incident light as the frequency is varied across the transition where photon energy exceeds the ionization energy (IE) of a material being examined by UPS. Label you axes.
Answer:
The equation for the Kinetic Energy, [tex]KE_e[/tex], of the photo-emitted electrons is given as follows;
[tex]KE_e = h\cdot f- BE[/tex]
Please find attached the required plot of the kinetic energy versus the frequency
Explanation:
The equation for the Kinetic Energy, [tex]KE_e[/tex], of the photo-emitted electrons is given as follows;
[tex]KE_e = h\cdot f- BE[/tex]
Where:
h = Planck's constant = 6.63×10⁻³⁴ J·s
f = Frequency
BE = Binding Energy = 2.71 eV for Calcium metal
f₀ = Threshold frequency for the material
The ionization energy is the energy required to free an electron from an isolated atom
Which location would be best for solar energy
Answer:
An area that has a lot of sun-light!
Explanation: