What is the wavelength of light emitted when the electron in a hydrogen atom undergoes transition from an energy level with n = 4 to an energy level with n = 2?
Answer:
[tex]4.86\times10^{-7}\ \text{m}[/tex]
Explanation:
R = Rydberg constant = [tex]1.09677583\times 10^7\ \text{m}^{-1}[/tex]
[tex]n_1[/tex] = Principal quantum number of an energy level = 2
[tex]n_2[/tex] = Principal quantum number of an energy level for the atomic electron transition = 4
Wavelength is given by the Rydberg formula
[tex]\lambda^{-1}=R\left(\dfrac{1}{n_1^2}-\dfrac{1}{n_2^2}\right)\\\Rightarrow \lambda^{-1}=1.09677583\times 10^7\left(\dfrac{1}{2^2}-\dfrac{1}{4^2}\right)\\\Rightarrow \lambda=\left(1.09677583\times 10^7\left(\dfrac{1}{2^2}-\dfrac{1}{4^2}\right)\right)^{-1}\\\Rightarrow \lambda=4.86\times10^{-7}\ \text{m}[/tex]
The wavelength of the light emitted is [tex]4.86\times10^{-7}\ \text{m}[/tex].
What carpet Burns in a deficiency of O2 a mixture of CO and CO2 forms.Carbon Burns in excess O2 to form only CO2 and CO Burns in excess O2 to form only CO2. Calculate ΔH for C(graphite +1/2O2) →CO(g).
Answer:
Explanation:
From the combustion of carbon, the reactions occurring in limited oxygen conditions are:
[tex]C(graphite) + \dfrac{1}{2}O_{2(g)} \to CO_{(g)}[/tex]
[tex]C(graphite) + O_{2(g)} \to CO_{2(g)}[/tex]
If it occurs in excess, then any leftover CO changes to CO2. i.e.
[tex]C(graphite) + O_{2(g)} \to CO_{2(g)}[/tex] ---- (1)
[tex]CO_{(g)} + \dfrac{1}{2}O_{(g)} \to CO_{2(g)}[/tex] ----- (2)
From (1), the enthalpy change is:
[tex]\Delta H_{rxn1} = \Delta H^0_{fCO_2(g)} - ( \Delta H^0_{f C(graphite)}+ \Delta H^0_{fCO_2(g)}[/tex]
[tex]\Delta H_{rxn1} =-393.5 \ kJ/mol -(0+0)[/tex]
[tex]\Delta H_{rxn1} =-393.5 \ kJ/mol[/tex]
From (2), the enthalpy change is:
[tex]\Delta_{rxn2} = \Delta H^0_{fCO_2(g)} - ( \Delta H^0_{fCO(g)} + \dfrac{1}{2} \Delta H^0_{fO_2(g)})[/tex]
[tex]\Delta_{rxn2} = -393.5 \ kJ/mol -(-110.5 + \dfrac{1}{2}(0))[/tex]
[tex]\Delta_{rxn2} = -283.0 \ kJ/mol[/tex]
Subtracting (2) from (1), we get:
[tex]C(graphite) + O_{2(g)} \to CO_{2(g)} \ \ \ \Delta H_{rxn} = -393.5 \ kJ/mol}[/tex]
[tex]CO_{(g)} + \dfrac{1}{2} O_2(g) \to CO_{2(g)}} \ \ \ \Delta H _{rxn2} = -283.0 \ kJ/mol[/tex]
[tex]C(graphite) + O_{2(g)} \to CO (g) + \dfrac{1}{2}O_{2(g)} \ \ \ \Delta H_{rxn} = -110.5 \ kJ/mol[/tex]
[tex]C(graphite) + \dfrac{1}{2} O_{2(g)} \to CO (g) \ \ \ \Delta H_{rxn} = -110.5 \ kJ/mol[/tex]
The enthalpy change ΔH of the reaction = -110.5 kJ/mol
Which two statements are true about all generators?
They convert motion energy to electric energy.
They have a fixed pair of magnets and a rotating metal coil.
They’re powered by fossil fuels.
They convert electric energy to motion energy.
They use the relative motion of a magnet and a coil of wire.
Answer:
they have a fixed pair of magnets and a rolling coil they convert motion into electric energy they are powered by fosile fuels they use reletive motion of a magnet and coil of a wire
Explanation:
Answer:
They convert motion energy to electric energy.
They use the relative motion of a magnet and a coil of wire.
Explanation:
This is the correct answer.
Mention any two factors that determines Cis/Trans Isomerization
Answer:
1. There most not be rotation within the molecule.
2. Two non identical group must be present in the double bonded carbon atom.
Explanation:
This is because cis/ trans isomerism are that exhibit different structural configurations where the atoms are spartially arranged. They are also refered to as geometric isomers. They cannot be interconverted at room temperature because it requires the bonds to be broken and restructured.
Cis shows that the functional groups on present in the same side which trans isomerism show that the functional groups are on opposite sides.
Tell me this why don't water stop my mouth from burning but milk or malk does this s for 32 points
Answer:
water spreads the spicy taste around your mouth, while milk does not and it helps the hot taste go away.
Explanation:
Answer:
water makes ur mouth burn more but milk it helps bc of what's in it
b. Which two neutral elements have different numbers of protons but similar properties?
Answer:
Helium and neon
Explanation:
PLZ HELP 2 mins left
Answer:
No matter how many times you cut it, its chemical properties won't change and it'll still be paper.
Explanation:
can someone plz help me with this..
Answer:
Sweets are sold loose, or pre-packed in 120g bags.
The 120 g bags are £1.49 each.
The loose sweets are £0.89 for 100g.
By calculating the price per gram, determine which is better value. Show your working.
Match the word with the definition. Write the correct letter in the space
provided. Reminder
that your answers should be blue.
A. Proton
B. Periodic Table
C. Atom
D. Chemical Symbol
E. Group
F. Atomic Number
G. Atomic Mass
H. Period
1. Electron
J. Neutron
K. Nucleus
1. Average mass of all the isotopes of that element
2. Series of elements arranged in rows on the periodic table
3 Smallest particle that still can be considered an element
4. Subatomic particle with no charge
5. An abbreviation of an element's name, usually one or two letters
6. Subatomic particles with a positive charge
7.
A small region in the center of an atom
8.
Arrangement of elements showing repeating pattern of their
properties
9. Series of elements arranged in columns on the periodic table
10.
Subatomic particles with a negative charge
11.
Number of protons in the nucleus of an atom
Answer:
this may be wrong and if it is im sorry
A=6
B=8
C=3
D=5
E=9
F=11
G=1
H=2
I=10
J=4
K=7
radiation is a measure of average kinetic energy of particles in an object true or false
Answer:false
Explanation:
The modern form of the periodic table results in the _____ ,which states that when elements are
arranged according to increasing atomic number
Answer:
The periodic law states “When elements are arranged in order of increasing atomic number, there is a periodic repetition of their chemical and physical properties
When KNO3 dissolved in water, what is the intermolecular
attraction between NO3-ions and H2O molecules?
Answer:Ion-dipole
Explanation:
The order is Solumedrol 3 mg/kg for a child weighing 20 kg. Solumedrol is available as 125 mg/2ml. How many ml will be given
Answer:
0.96mL must be given
Explanation:
First, we need to obtain the mass of Solumedrol required for the child by using its mass. Then, with this mass we can solve the volume that must be administered:
Mass of solumedrol required:
20kg * (3mg / kg) = 60mg of solumedrol are required.
Volume given:
60mg Solumedrol * (2mL / 125mg) =
0.96mL must be given
Which of the following would be most likely to experience strong intermolecular forces?
A. Molecules that contain no electrically charged regions.
B. Molecules that contain atoms of oxygen.
C. Molecules that are composed of solely ions.
D. Molecules that have both negatively and positively charged parts.
Answer:
The correct answer is D
Explanation:
Just took quiz
Air masses carry their own weather.
True
False
The question is number 8
HC2H3O2 chemical compound?
Answer:
Ethanoic or acetic acid.
Explanation:
Hello!
In this case, since the chemical formula of the compound excludes the hydrogen from the CHO form, we can infer it is a leaving group, which is likely to be bonded with an oxygen due to the high polarity of the O-H bond. In such a way, the most feasible condensed structure is:
[tex]CH_3-COOH[/tex]
Whereas the COOH stands for the carboxyl group; therefore the compound is ethanoic acid or acetic acid.
Regards!
what is the answer to this question?
Answer:
Vertebrae
Explanation:
Vertebrae are the 33 individual bones that interlock with each other to form the spinal column. The vertebrae are numbered and divided into regions: cervical, thoracic, lumbar, sacrum, and coccyx (Fig. 2). Only the top 24 bones are moveable; the vertebrae of the sacrum and coccyx are fused.
I believe the answer is vertebrae. There are 24 bones stacked up on each other that make up your backbone.
How are food webs and food chains related? HELP IF YOU WANT BRAINLEIST!!
Food webs only contain consumers.
Food webs consist of only one food chain.
Food webs are made of many food chains.
Food webs only contain producers.
Answer: Food webs are made of many food chains is the answer.
Explanation:
Food web consists many food chains.
Select the correct answer.
Which of these activities increases the amount of carbon in the atmosphere?
O A.
animals eating plants
OB. burning of fossil fuels
OC. fossilization
O D.
photosynthesis
Popcorn popping in a pot on the stove is an example of:
answer: conduction radiation convection The Kelvin scale
Answer:
convection
Explanation:
i believe
The popcorn in the pot pops up because of the conduction process when heated. The solid particles transfers heat energy by conduction mode.
What is conduction?There are three mode of heat transfer namely, conduction, convection and radiation. Conduction is taking place in solids whereas, convection is taking place in liquids and gases. Radiation is the way of heat transfer through vacuum.
In conduction, the heat energy transfers from one molecule to the other which are closely packed in the solids as in a chain. Thus, heat easily moves through the chain.
In gases and liquids, the hot molecules moves to the surface to make other molecules hot and this flow of molecules make the entire substance hot.
Popcorn is a solid substance thus, able to conduct heat energy. This heat energy leads them to thermal vibration and they pop up from the hot pot. Therefore, it is an example of conduction.
To find more on conduction, refer here:
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What is the region of a longitudinal wave where particles are closest together called?
Answer:
compressions
Explanation:
in a longitudinal wave, particles of the medium vibrate in a direction that is parallel to the direction that the wave travels. places where particles of the medium crowd closer together are called compressions. places where particles of the medium spread farther apart are called rarefactions
The region of a longitudinal wave where particles are closest together is a Compression. A further explanation is below.
CompressionsThe process of re-encoding knowledge such that it consumes fewer bits of information than the original information.
Compression has been frequently sometimes used speed things up the transportation of data such as words as well as visual graphics, and even to reduce the amount of memory required to retain such content.
Find out more information about compressions here:
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Determine the molar mass of Cao
Answer:
Molar mass of CaO
(40 + 16)g
= 56g
hope it helps you
Which two forces keep the planets
and moons in their orbits?
Answer:
“Without gravity, the planets' inertia would keep them moving in straight lines. Gravity “steers” the planets in their oval paths around the Sun. Together, gravity and inertia keep the planets in their orbits.”
Explanation:
BRAINLIEST PLZZZ
Using the two cell reduction potentials shown for their corresponding reaction, calculate the cell potential for a voltaic cell made from these two systems.
Question 17 options:
A)
1.68 V
B)
–0.78 V
C)
0.78 V
D)
–1.68 V
Answer:
Theory- 1 to 7
Explanation:
Exercise- 8 to 25
ect
The right alternative is Option D (0.78 V).
According to the question,
By putting the values, we get
Cu+2 + 2e → Cu E = 0.52 V
Ag+1 + 1e Ag E° = 0.78 V
= 1.23 - 0.45
= 0.78.
Is cell potential negative or positive?negative
The standard cell potential is quite negative, so the reaction will not occur spontaneously as written.
Missing parts of the question.
Using the two cell reduction potentials shown for their corresponding reaction, calculate the cell potential for a voltaic cell made from these two systems: 0.78.
Cu+2 + 2e → Cu E = 0.52 V
Ag+1 + 1e Ag E° = 0.80 V
options:
A)
0.28 V
B)
–1.32 V
C)
1.32 V
D)
–0.28 V
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What Is an example of weather?
A. The average rainfall in Arizona over the pervious three months
B. The increase in temperature over North America over the past decade
C. The time for high tide in Daytona Beach today
D. The temperature and wind speed in Philadelphia today
THE WEATHER BALLOON DATA WE STUDIED WAS MEASURED AND RECORDED AT MIDNIGHT. THE TEMPERATURE OF THE AIR AT Earth's SURFACE IS DIFFERENT DURING DIFFERENT TIME OF THE DAY. WHAT OTHER TIMES OF THE DAY COULD WE MEASURE THE SURFACE TEMPERATURES OUTSIDE THE SCHOOL BUILDING? WHY? Write your thought on a sticky note and add it to our board. (Please initial your note.)
Answer night
Explanation:
because day is to hot
Which of the following is true about the climate of Anchorage?
The winters are cold and snowy.
The snow was piled next to the landing strip.
It was 27°F.
Summers are cold in Anchorage.
Answer:
A
Explanation:
Is the following compound symmetrical going across?
Answer:
Yes
Explanation:
A molecule has a center of symmetry when, for any atom in the molecule, an identical atom exists diametrically opposite this center an equal distance from it(Wikipedia).
A center of symmetry is said to exist in a molecule when reflection of all parts of the molecule through the center of symmetry produces an indistinguishable configuration(Housecroeft and Sharpe,2012)
Obviously, the Cl2 molecule has a center of symmetry, hence it is symmetrical. Reflection of the molecules through its center of symmetry produces an indistinguishable configuration.
What ara the differences between the homolytic and heterolytic bond dissociation ? And why homolytic dissociation energy of H-H (104 KJ/mol) is lower than its heterolytic bond dissociation energy (401 KJ/mol)?
Answer:
Following are the difference in homolytic and hetrolytic bond dissociation.
Homolytic dissociation is referred as the amount of energy released during homolytic fission. Homolytic fission is known as the dissociation of chemical bond in two equal fragmentswhereas, Hetrolytic dissociation is referred as the amount of energy released during Hetrolytic fission. Hetrolytic fission is known as the dissociation of chemical bond in two unequal fragments.Homolytic fission gives one electron each to its fragments whereas Hetrolytic fissiongives two electron to one fragment and zero electron to other fragment.Energy released during Homolytic fission is lower than the Hetrolytic fission as the electron distribution to its fragments is uniform in homolytic whereas electron distribution to its fragments is uniform in hetrolytic fission.
Thus bonds form in hetrolytic fission is more stronger than the the bonds formed in homolytic fission.
Hence, more energy is required to break the bonds of hetrolytic fission as compared to homolytic fission
Thus, homolytic dissociation energy of H-H (104 KJ/mol) is lower than its heterolytic bond dissociation energy (401 KJ/mol)
Which symbol can be used to indicate the pressure at which a chemical reaction is carried out?
25°C
OA
2 atm
Pt
Answer:
2 atm
Explanation:
The symbol 'atm' is used for pressure. Hence, the symbol used to indicate the pressure at which a chemical reaction is carried out can be, 2 atm.