Answer:
The absorption and strength of the H-beta lines change with the temperature of the stellar surface, and because of this, one can find the temperature of the star from their absorption lines and strength. To better comprehend, let us look into the concept of the atom's atomic structure.
Atoms possess distinct energy levels and these levels of energy are constant, that is, the temperature has no influence on it. However, temperature possesses an influence on the electron numbers found within these levels of energy. Therefore, to generate an absorption line of hydrogen in the electromagnetic spectrum's visible band, the electrons are required to be present in the second energy level, that is when it captivates a photon.
Therefore, after captivating the photons the electrons jump from level 2 to level 4, which shows that there is an increase in the stellar surface temperature and at the same time one can witness a decline in the strength of the H-beta lines. In case, if the temperature of the surface increases too much, then one will witness no attachment of electron with the hydrogen atom and thus no H lines, and if the temperature of the surface becomes too low, then the electrons will stay in the ground state and no formation of H lines will take place in that condition too.
Hence, to generate a very robust H line, after captivating photons the majority of the electrons are required to stay in the second energy level.
the diagram above represents a reflex arc in a human. This pathway responds when someone touches something that causes pain, such as a hot stove. Which of the following shows the correct order of the body systems involved in this response?
A) Integumentary, respiratory, digestive
B) Circulatory, respiratory, nervous
C) Integumentary, nervous, muscular
D) Circulatory, digestive, nervous
Answer:
C) Integumentary, nervous, muscular
Explanation:
When a human body touches a hot stove , our sense organ which is integumen first of all receives the impulse of heat . The impulse is transformed into electrical signal which is transmitted to brain which is a part of nervous system . Then brain processes it and command signal is sent to muscle of hand to move it away from that place . Hence the order is
Integumentary, nervous, muscular .
How to make isopropyl alcohol
Answer:
.It is easily synthesized from the reaction of propylene with sulfuric acid, followed by hydrolysis. Isopropyl alcohol (2-propanol) is made by indirect hydration of propylene (CH2CHCH3).… In some cases the hydration of propylene is carried out in one step, using water and a catalyst at high pressure.
Hope it'll help!
stay safe:)
Which picture shows how the moon from earth when it’s in the position
Explanation:
This picture shows how the moon from earth when it is in position
2. What are the similarities between law of triads and law of octaves?
Answer:
The similarities are the groups, triads law is a law where they are in groups or three, the octaves law is the 'best' law, is the one who every atom wants, they do everything to be in groups of eight.
Explanation:
At constant pressure, what generally happens to the solubility of solids and gases when the temperature of a solution is increased?
A. The solubility of solids and gases increases.
B. The solubility of solids and gases decreases.
C. The solubility of solids increases, and the solubility of gases decreases.
D. The solubility of solids decreases, and the solubility of gases increases.
Answer:
C)
Explanation:
JUST DID IT
Answer:
A D E
Explanation:
just did it
The roles of hydrochloric acid (HCl) in the digestive system?
Answer:
There are several roles of HCl in the digestive system. Some of them are as follows:
There is HCl present in the gastric juice of your stomach, otherwise known as stomach acid. The acidic nature of the HCl in the stomach acid make it useful for quickly breaking down food.HCl's acidic nature also allows it to kill bacteria and other pathogens that you may have ingested, keeping you safe from their dangerous effects.HCl can also contribute Hydrogen ions, which helps to activate pepsinogen, a substance secreted by the stomach wall. The activated pepsinogen is then converted into pepsin, which aids in the digestion of proteins. Because of this, HCl essentially keeps the systems of protein digestion in check. Too much or too little of it can be dangerous.HCl also makes sure that vitamins are properly absorbed and acts as a communicator to other organs in the digestive system.When you add a controlled amount of substance known as an impurity to a pure semiconductor, its conductivity increases. This process is known as doping. The addition of an impurity can increase or decrease the number of available electrons. If the number of electrons is increased, the extra electrons conduct electricity. If the number of electrons is decreased, a vacant hole is created. The adjacent electron enters the vacant hole and conducts electricity. Thus, it seems like the holes act as charge carriers. They are considered to be positive charge carriers. Depending upon the charge carriers that conduct electricity, there are two types of semiconductors: p-type semiconductors and n-type semiconductors.Which of the following statements are correct with respect to semiconductors?
a) The addition of group 3A elements to group 4A semiconductors decreases the conductivity of the group 4A semiconductors.
b) The conductivity of semiconductors can be increased by the doping process.
c) As the temperature increases, the conductivity of semiconductors decreases.
d) The addition of group 5A elements to group 4A semiconductors increases the conductivity of the group 4A semiconductors.
e) Holes are charge carriers in p-type semiconductors.
f) Electrons are charge carriers in n-type semiconductors.
Answer:
See explaination
Explanation:
1. The addition of group 3A elements to group 4A semiconductors decreases the conductivity of the group 4A semiconductors: Wrong
The addition of 3A group elements inreases the conductivity and make them extrinsic semiconductors( p-type)
2. The conductivity of semiconductors can be increased by the doping process.: Correct
3.As the temperature increases, the conductivity of semiconductors decreases.. wrong
As the temperature increases, the conductivity of semiconductors increases.
4. The addition of group 5A elements to group 4A semiconductors increases the conductivity of the group 4A semiconductors: Correct : They will create n-type semicoductor.
5.Holes are charge carriers in p-type semiconductors: Correct
6. Electrons are charge carriers in n-type semiconductors: Correct
Which diagram correctly describes the changes that occur as a small piece of rock falls from space and hits the earth
Answer:
the motion of gravity
Explanation:
Answer:
its c
Explanation
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What is the concentration of a solution if 0.450 mol of NaCl dissolved in 750 mL of water?
Answer:
.6mol/L
Explanation:
molarity = number of moles / volume of solvent (in L)
750mL / 1000mL/L = .75L
M = .450mol / .75L
M = .6mol/L
A chemist wants to increase the solubility of a solid in water. Which of the
following will NOT help? *
-increase the temperature
-decrease the particle size
-Increase stirring
-increase pressure
Answer:
- Increase pressure .
Explanation:
Hello,
In this case, during the dissolution process, the solute's molecules rearrange in order to get together with the solvent's molecules, in this case water.
Now, since we are talking about a solid whose particles are intimately held together, the only way to separate them is by increasing the temperature because the molecules start moving so they can join water's molecules, decreasing particle size since they will be more likely to separate to each other and increasing stirring since the applied energy will break the solid's intramolecular forces.
In such a way, since pressure significantly affects gases and slightly affects liquid, it is not able to modify a solid, just extreme pressures such as it needed to produce diamonds, is able to affect a solid. For that reason, increasing the pressure will not increase the solid's solubility.
Best regards.
What is the total amount of energy needed to heat 22.6 g of titanium from 1420oC to 1590oC in joules?
Answer:
[tex]Q=2091J=2.091kJ[/tex]
Explanation:
Hello,
In this case, the formula we use to compute the heat Q by increasing the temperature, in terms of the mass and the heat capacity is:
[tex]Q=mCp(T_2-T_1)[/tex]
Titanium's heat capacity is 0.544284 J/g°C, thus, the for such temperature increase, the heat results positive as shown below:
[tex]Q=22.6g*0.544284\frac{J}{g^oC}*(1590^oC-1420^oC) \\\\Q=2091J=2.091kJ[/tex]
Best regards.
What is the symbol for the entity that has 17 protons, 20 neutrons, and 18 electrons?
hEy!!!
Chlorine(CL) is the symbol for the entity that has 17 protons,20 neutrons and 18 electrons.
Hope it will be helpful to you...
Answer:chlorine
Explanation:
What is the hydronium ion concentration of a 0.100 M acetic acid solution with Ka = 1.8 × 10-5? The equation for the dissociation of acetic acid is: CH3CO2H(aq) + H2O(l) ⇌ H3O+(aq) + CH3CO2-(aq) What is the hydronium ion concentration of a 0.100 M acetic acid solution with Ka = 1.8 × 10-5? The equation for the dissociation of acetic acid is: CH3CO2H(aq) + H2O(l) ⇌ H3O+(aq) + CH3CO2-(aq) 1.3 × 10-2 M 4.2 × 10-2 M 1.3 × 10-3 M 4.2 × 10-3 M
Answer:
1.3×10⁻³ M
Explanation:
Hello,
In this case, given the dissociation reaction of acetic acid:
[tex]CH_3CO_2H(aq) + H_2O(l) \rightleftharpoons H_3O^+(aq) + CH_3CO_2^-(aq)[/tex]
We can write the law of mass action for it:
[tex]Ka=\frac{[H_3O^+][CH_3CO_2^-]}{[CH_3CO_2H]}[/tex]
Of course, excluding the water as heterogeneous substances are not included. Then, in terms of the change [tex]x[/tex] due to the dissociation extent, we are able to rewrite it as shown below:
[tex]1.8x10^{-5}=\frac{x*x}{0.100-x}[/tex]
Thus, via the quadratic equation or solve, we obtain the following solutions:
[tex]x_1=-0.00135M\\x_2=0.00133M[/tex]
Obviously, the solution is 0.00133M which match with the hydronium concentration, thus, answer is: 1.3×10⁻³ M in scientific notation.
Regards.
Answer:
1.3×10^-3 M
Explanation:
Step 1:
Data obtained from the question:
Equilibrium constant (Ka) = 1.8×10^-5
Concentration of acetic acid, [CH3COOH] = 0.100 M
Concentration of hydronium ion, [H3O+] =..?
Step 2:
The balanced equation for the reaction.
CH3CO2H(aq) + H2O(l) ⇌ H3O+(aq) + CH3CO2-(aq)
Step 3:
Determination of concentration of hydronium ion, [H3O+].
This can be obtained as follow:
Ka = [H3O+] [CH3CO2-] / [CH3CO2H]
Initial concentration:
[CH3COOH] = 0.100 M
[H3O+] = 0
[CH3CO2-] = 0
During reaction
[CH3COOH] = – y
[H3O+] = +y
[CH3CO2-] = +y
Equilibrium:
[CH3COOH] = 0.1 – y
[H3O+] = y
[CH3CO2-] = y
Ka = [H3O+] [CH3CO2-] / [CH3CO2H]
1.8×10^-5 = y × y / 0.1
Cross multiply
y^2 = 1.8×10^-5 x 0.1
Take the square root of both side
y = √(1.8×10^-5 x 0.1)
y = 1.3×10^-3 M
[H3O+] = y = 1.3×10^-3 M
Therefore, the concentration of the hydronium ion, [H3O+] is 1.3×10^-3 M
It takes 300 N to move a box 10 meters in 10 seconds. How much power is
required?
A. 30,000 W
B. 100 W
C. 3,000 J
D. 300 W
Plz help
Answer:
Power, P = 300 W
Explanation:
We have,
Force acting on the box to take it is 300 N
It is moved to a distance of 10 m in 10 seconds
It is required to find the power required to move the box. The rate at which work is done is called power required by an object. It can be given by the formula as follows :
[tex]P=\dfrac{W}{t}\\\\P=\dfrac{Fd}{t}\\\\P=\dfrac{300\times 10}{10}\\\\P=300\ W[/tex]
So, the power required is 300 W.
Based on the diagram below, how much of the excess reactant is left over? *
2 slices of bread and 3 pieces of lunchmeat
2 slices of bread and 2 slices of cheese
2 of lunchmeat and 3 slices of cheese
3 of lunchmeat and 2 slices of cheese
Answer:
3 pieces of lunch-meat and 2 slices of cheese
Explanation:
You have enough bread to make 3 sandwiches
You have enough lunch-meat to make 4 sandwiches
You have enough cheese to make 5 sandwiches
In all you have enough material to make 3 sandwiches
so if you subtract three from each number above you will have no bread, enough lunch-meat to make one sandwich and enough cheese to make two sandwiches
luch-meat for one sandwich is: 3 pieces
Cheese for two sandwiches is: 2 pieces
3. Infer A forgotten ice pop lies melting on a deck on a hot summer day. What is the direction of heat flow as the ice pop melts?
Is the process endothermic or exothermic? Explain.
Answer:
Endothermic. The energy is flowing into the molecules causing them to break apart and the ice pop change state.
Answer:
Yes, an autumn day isn’t cold enough to keep an ice pop at freezing temperatures.
What is the molarity of sodium hydroxide solution made by combining 2.0 L of 0.60
NaOH With 495 mL 3.0 M NaOH? Assume the volumes of the two solutions to be additive___M
Answer:
[tex]M=1.1M[/tex]
Explanation:
Hello,
In this case, since we are mixing two NaOH solutions, the first step is to compute the total moles once the mixing is done, by using the volumes and concentrations of each solutions and subsequently adding them:
[tex]n_T=2.0L*0.60\frac{mol}{L}+495mL*\frac{1L}{1000mL}*3.0\frac{mol}{L}= 2.7molNaOH[/tex]
Next, we compute the total volume by adding the volume of each solution:
[tex]V_T=2.0L+495mL*\frac{1L}{1000mL}= 2.495L[/tex]
Finally, we compute the molarity of the resulting solution by the division between the total moles and the total volume:
[tex]M=\frac{2.7mol}{2.495L}\\ \\M=1.1M[/tex]
Best regards.
Which factor would slow down a chemical reaction? (Choose all that apply)
A)Adding an inhibitor
B)Decreasing temperature
C)Decreasing particle size
D)Increasing particle size
Answer:
(decreasing particle size) C
Explanation: That is one of the answers, if there are more I am sorry.
If an insufficient amount of liquid unknown had been used, how would this have effected the value of the experimental molar mass
Answer:
Actual yield reduces the more.
Explanation:
An actual yield of the course of a chemical reaction is the mass of a product actually obtained from the reaction.
In practice you see it and It is usually less than the theoretical yield.
Various reasons may come up to explain this away but here is one:
• incomplete reactions, simply put here some of the reactants do not react to form the product.
The same applies in the question about the actual yield will reduce significantly in molar mass now that insufficient amount of reagent are used.
Describe an autopsy table
After the body is cleaned, the body is weighed and measured before being placed on the autopsy table for reexamination. The autopsy table is typically a slanted, aluminum table with raised edges that has several faucets and drains used to wash away collecting blood during the internal investigation.
Answer:
A table used to scientifically determine the cause of death of a human or animal
Explanation:
How many moles
are equal to
4.11x1023
molecules of
CO2?
Explanation:
6.02×1023 culture atoms have a mass of 63.5g. 12.0g. c +23.0g O2__44.0g CO2.(12.0+16.0+16.0=44.0g).1 mol 1 mol. 1 mol number molecules weight
The number of molecules in one mole of carbon dioxide is 6.02 × 10²³. Therefore, the number of moles of carbon dioxide which contains 4.11 × 10²³ molecules is 0.68.
What is Avogadro number ?The number of atoms that constitutes one mole of a substance is called Avogadro number. It is equal to 6.02 × 10²³. Thus, one mole of every elements contains Avogadro number of atoms.
Similarly, one mole of a compound contains 6.02 × 10²³ number of molecules. Thus, one mole of carbon dioxide contains these much molecules.
Given the number of molecules of carbon dioxide = 4.11 × 10²³
Then, no.of moles = number of molecules/ Avogadro number.
no.of moles = 4.11 × 10²³ /6.022 × 10²³ = 0.68.
Therefore, the number of moles of CO₂ that contains 4.11 × 10²³ molecules is 0.68.
Find more on Avogadro number:
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Dysphagia is the name of a disorder that disrupts
А
the swallowing reflex
B
the absorption of essential nutrients
acid levels in the stomach
C
D
the stomach lining
Answer:
A. The Swallowing reflex
Explanation:
Dysphagia Is a a condition that makes swallowing difficult.
if a sample of gas at 25.2 c has a volume of 536mL at 637 torr, what will its volume be if the pressure is increased to 712 torr?
If you start with 64g of a radioactive element how many half-lives would occur before 8g remain?
Answer:
3 half-lives
Explanation:
The half-life is the time that it takes to a radioactive element to decay to half of its initial amount.
Let's suppose we start with 64 g of the radioactive element.
After 1 half-life, the mass of the element will be 32 g.After 2 half-lives, the mass of the element will be 16 g.After 3 half-lives, the mass of the element will be 8 g.please do this guys i need a lot of help please!
Answer:
the European countries grew together.
Explanation:
Europe saw human inflows from east and southeast.
the Roman Empire came to dominate the entire Mediterranean basin.
European politics from 1947 to 1989 made the European countries grew together.
Helium occupies a volume of 3.8 L at –45°C. What was its initial temperature when it occupied 8.3 L?
Answer:
98.3 gradius Celsius
Explanation:
This problem is solved using the Ideal Gas Equation
pV = nRT
...
Please see the step-by-step solution in the picture attached below.
Hope this answer can help you. Have a nice day!
Which statements describe inorganic compounds? Check all that apply
Inorganic compounds contain carbon
Inorganic compounds usually lack carbon
Inorganic compounds are not associated with or made from living things,
Inorganic compounds include fruits and vegetables,
Inorganic compounds include salt and water
Answer:
b, c, e
Explanation:
Inorganic compounds usually lack carbon.
Inorganic compounds are not associated with or made from living things.
Inorganic compounds include salt and water.
Answer:
yes the answer id bce
Explanation:
The glass of a lit 75-watt incandescent bulb is hotter to the touch than the glass of a 25-watt compact fluorescent (CFL) bulb that emits the same amount of light. What could be a reason for this
Use the graph to determine which is greater, the heat of fusion or the heat of vaporization. Explain how you used the graph to determine that.
(The substance is water)
Answer:
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If I add 50 mls of water to 300 mls of 0.6M KNO3 solution, what will be the molarity of the diluted solution?
Answer:
[tex]M_2=0.51M[/tex]
Explanation:
Hello,
In this case, for this dilution process, we understand that the moles of the solute (potassium nitrate) remain unchanged upon the addition of diluting water. However, the resulting or final volume includes the added water as shown below:
[tex]V_2=300mL+50mL=350mL[/tex]
In such a way, we are able to relate the solution before and after the dilution by:
[tex]V_1M_1=V_2M_2[/tex]
Hence, we solve for the final molarity as:
[tex]M_2=\frac{M_1V_1}{V_2}=\frac{0.6M*300mL}{350mL}[/tex]
Best regards.
[tex]M_2=0.51M[/tex]
