Explanation:
The first step in this problem is to convert the wavelength, λ, to a frequency, ν, and
then calculate the energy of the photon using ε = hν. In such problems you must take
care to use a consistent set of units. We will use S.I. units. Thus,
λ = 18900 Å = 18900 x 10–10 m = 1.89 x 10–6 m
The frequency associated with this wavelength is given by:
ν = c/λ = (3.00 x 108 m s–1 ) / (1.89 x 10–6 m) = 1.59 x 1014 s–1
The energy ε associated with a photon of this frequency is:
ε = h ν = (6.626 x 10–34 J s) (1.59 x 1014 s–1) = 1.05 x 10–19 J
Note -- the ENERGY of this photon corresponds to a DIFFERENCE between
energy levels of the H atom
The energy levels for the H atom are given by:
εn = (–21.8 x 10–19 J) / n2 ; where n = 1,2,3,4,.............
Thus, ε1 = –21.8 x 10–19 J; ε2 = –5.45 x 10–19 J
ε3 = –2.42 x 10–19 J; ε4 = –1.36 x 10–19 J
We now seek an ENERGY LEVEL DIFFERENCE which matches the energy of the
photon.
We see that the electronic transition which gives rise to an EMITTED photon with
energy ε = 1.05 x 10–19 J is:
ninitial = 4 → nfinal = 3
2. A series of spectral lines in emission is characterized by a common value of nfinal -- i.e.
the quantum number of the level at which the transition terminates. Since the 18900 Å
line arises from a transition in which ninitial = 4 and nfinal = 3, the series to which it
belongs is characterized by nfinal = 3. The series limit for this series of emission lines is
the wavelength that would correspond to the transition ninitial = ∞ to nfinal = 3
From the energy level expression given in problem1 we see that:
ε∞ = (–21.8 x 10–19 J) (1/ ∞2) = 0
Why did the increase in consumerism occur in the Roaring Twenties?(1 point)
A. There were new technologies and new innovations to drive the sale of goods, since people could afford them.
B. Improvements in technology made life easier for all people.
C. Machines and robots were used on assembly lines, making production more efficient.
D. People were tired of the economy only producing necessary supplies.
Answer:
A. There were new technologies and new innovations to drive the sale of goods, since people could afford them
Explanation:
239
239
-
93Np
94Pu + c
Answer:4>34.1>56
Explanation:ez
Based on the figure below, what do the elements of a group (family) have
in common
Answer:
Explanation:
Send figure below
I need help I know it isnt A
State which statement is a physical change or a chemical change:
(a) Sawing wood
(b) Cooking eggs
(c) Melting chocolate
(d) Chewing sweets
(e) Rusting iron
(f) Filing your fingernails
(g) Milk turning sour
(h) Blow-drying your hair
(i) Boiling water
(j) Baking a cake
(k) Burning a match
Answer:
Physical change: A,C ,D, F, H, I
Chemical Change: B, E, G, J, K
Write a Formula
Compound Name: Strontium Sulfate
Answer:
it's SrSO4
Explanation:
Which of the following elements is a metalloid? A. phosphorus B. cobalt C. silicon D. magnesium
Answer: silicon
Explanation:it just is
Respuesta
es la C. silicio
Explanation:
No existe una definición estandarizada de elemento metaloide ni un consenso completo sobre los elementos que son metaloides.
En la clasificación de metaloides se suelen incluir a:
Boro (B)
Silicio (Si)
Germanio (Ge)
Arsénico (As)
Antimonio (Sb)
Telurio (Te)
Can someone pls answer quickly?
answer is atom.Hope it is helpful.
Answer:
Atoms are the smallest particles that made up matter.
Li and S - covalent or ionic bond?
Answer:
It is an ionic bond.
Explanation:
Ionic bonds occur when a metal and a nonmetal combine, while covalent bonds occur between two nonmetals. Lithium is a metal and sulfur is a nonmetal.
how is sonoluminescence similar to what we see in fireworks?
Answer:
Explanation:
Sonoluminescence is a phenomenon in which small gas bubbles burst to produce light when intense sound wave is introduced. Thus, it can be said that sound energy is converted to light energy here. This is similar to the process of how fire crackers work except that sonoluminescence occurs in a liquid medium while firecrackers work in solid media. In firecrackers, when the tip is lit with fire, the initial explosion is caused by the expansion of some nitrogen and carbon present in some constituent compounds, this explosion produces heat which causes some other constituent chemicals in the firecracker to quickly react and produce light. Thus, this can also be said to convert sound energy to light energy and are thus similar to what occurs in sonoluminescence.
A block of lead displaces 50.5ml of water. The block weighs 698 g. From this
information, calculate the density of lead.
Answer:
13.82 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question we have
[tex]density = \frac{698}{50.5} \\ = 13.8217...[/tex]
We have the final answer as
13.82 g/mLHope this helps you
can somebody help me with this please
Answer:
He, 2, 2, 2, 4, 4-2=2, 1, 8
I, 53, 53, 53, 127, 127-53= 74, 5, 7
Explanation:
um check the periodic table for the rest?
What is the second life cycle stage during complete metamorphosis of insects?
O A) The eggs hatch into larvae.
OB) The eggs hatch into nymphs.
OC) Nymphs stop molting and are adult sized.
OD) Larvae make hard, protective cases around themselves during the pupal stage.
Answer:
They hatch into larvae.
Explanation:
Which of these mixtures is a suspension?
A. salad dressing
B. Gelatin
C. whipped cream
D. apple juice
Answer:
D. apple juice
Explanation:
You are so excited-your first summer job! You are a hot-tub maintenance assistant. You travel to homes, making sure the pH of their hot-tub water is correct (between 7 and 7.6), and adjusting and cleaning when necessary. But before you get started, you need to answer the following questions. What is pH? What do you use to test it? Why would it be important to keep the pH of hot-tub water between 7 and 7.6?
Answer: well i guess we can say that is a scale used to specify the acidity or basicity of an aqueous solution and it is important to keep ph of hot tub water between 7 and 7.6 because if it is not balanced the water can negatively affect your tub.
Explanation:
pH is an extremely important chemical level to maintain in your spa's water chemistry. A high pH or a low pH will spell trouble for you and your spa. On the pH scale, a reading of 7.4-7.6 indicates perfectly balanced pH. Any number lower than 7.4 means that your water is now considered “acidic”.
Answer:
pH is a scale to measure the acidity or basicity of a substance such as water, it would be important to keep the pH of hot-tub water between 7 and 7.6 because if the acidity is too high, the walls of the hot-tub may be damaged, and if the pH is too low, the heating thing may get damaged.
Explanation:
The Synthesis Reaction of aluminum (Al) and iodine (I) forms a new, more complex
product. What is the product?
Answer:
Aluminum iodide (AlI₃)
Explanation:
The synthesis reaction of aluminum (Al) and iodine (I) can be illustrated as shown below:
Aluminium exhibit trivalent positive ion (Al³⁺)
Iodine exhibit univalent negative ion (I¯)
During reaction, there will be an exchange of ion as shown below:
Al³⁺ + I¯ —> AlI₃
Thus, we can write the balanced equation for the reaction as follow:
Al + I₂ —› AlI₃
There are 2 atoms of I on the left side and 3 atoms on the right side. It can be balance by putting 2 in front of AlI₃ and 3 in front of I₂ as shown below:
Al + 3I₂ —› 2AlI₃
There are 2 atoms of Al on the right side and 1 atom on the left side. It can be balance by putting 2 in front of Al as shown below:
2Al + 3I₂ —› 2AlI₃
Thus the equation is balanced.
The product on the reaction is aluminum iodide (AlI₃)
Write the chemical formula for gold (I) sulfide.
Answer
Au2s
please mark me as brainlist
What is the enthaply of dissolution?
Answer:
The enthalpy change of solution refers to the amount of heat that is released or absorbed during the dissolving process (at constant pressure).
Explanation:
7th grade help me plzzzzzzzz
Answer:
1. Metals
2. Solid, gas, liquid
Explanation:
For #1:
The majority of elements in the periodic table are classified as metals. The transition metals lie in the center of the table, spanning groups three through 12. These elements are solid at room temperature, except mercury, and have the metallic color and malleability expected of metals.
Hope this helps :)
The three types of symbiosis are ___ and ___
Answer:
mutualism,commensalism and parasitism
Answer:
mutualism, commensalism, and parasitism
A solid is composed entirely of xenon atoms. What type of solid is it?
a) ionic
b) metallic
c) covalent network
d) atomic
e) molecular
f) amorphous
Answer:
ionic
Explanation:
xenom atoms are too large to move in the crystals without first associating with two oxygen ion vacancies and one uranium ion vacancy
In the following reaction, how many grams of H2O are produced if 2.00 g of N2H4 react? N2H4 + 3 O2 ---> 2NO2 + 2H2O
Answer:
2
Explanation:
From this equation, 2 grams are produced.
The mass of H₂O produced from the reaction is 2.25 g
We'll begin by calculating the mass of N₂H₄ that reacted and the mass of H₂O produced from the balanced equation.
N₂H₄ + 3O₂ —> 2NO₂ + 2H₂O
Molar mass of N₂H₄ = (2×14) +(4×1) = 32 g/mol
Mass of N₂H₄ from the balanced equation = 1 × 32 = 32 g
Molar mass of H₂O = (2×1) + 16 = 18 g/mol
Mass of H₂O from the balanced equation = 2 × 18 = 36 g
SUMMARY
From the balanced equation above,
32 g of N₂H₄ reacted to produce 36 g of H₂O.
Finally, we shall determine the mass of H₂O produced by the reaction of 2 g of N₂H₄From the balanced equation above,
, 32 g of N₂H₄ reacted to produce 36 g of H₂O.
Therefore,
2 g of N₂H₄ will react to produce = (2 × 36) / 32 = 2.25 g of H₂O
Thus, the mass of H₂O produced from the reaction is 2.25 g
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helppp mehhh thanks:))
Answer:
natural gas
Explanation:
your welcomeee
Convert 62.5 L to mm
3
Answer:
0.0625
Explanation:
Answer:
62,500
Explanation:
In this periodic table, which type of element is shown in green boxes?
A. Noble gases
B. Metalloids
C. Nonmetals
D. Metals
The correct answer is B. Metalloids
Explanation:
In this periodic table, the green boxes include elements such as Boron (B), Arsenic (As), and Antimony (Sb). All these elements are known in chemistry as semimetals or metalloids. This classification is because these elements cannot be completely classified into metals or non-metals. Moreover, they all display similar properties including some level of conductivity, malleability, and solid-state. According to this, the correct answer is B.
Answer:
B. Metalloids
Explanation:
2) Gas in a balloon occupies 3.3 L. What volume will it occupy if the pressure
is changed from 100 kPa to 90 kPa,
Answer:
The answer is 3.7 LExplanation:
The new volume can be found by using the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
Since we are finding the new volume
[tex]V_2 = \frac{P_1V_1}{P_2} \\[/tex]
From the question we have
[tex]V_2 = \frac{3.3 \times 100000}{90000} = \frac{330000}{9000 } \\ = 3.666666...[/tex]
We have the final answer as
3.7 LHope this helps you
3 way to make bases
What is the density of an object (g/cm) that has a mass of 2.78 g & a volume of 10.0
cm3?
Answer:
The answer is 0.28 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question we have
[tex]density = \frac{2.78}{10} \\ = 0.278[/tex]
We have the final answer as
0.28 g/cm³Hope this helps you
Answer:
p = 0.278 g/cm3
Explanation:
explain how you know the numbers of atoms in your formula. Carbon Monoxide
Explanation:
hrhrbdbc hdbdbdhdbdbdbdebebebrbbrbrdbbc bf bdvdbf bdbdbdbdbdhdhdhdhdhdhdhdhdhdhdhdhdhdhdhdhdhdhdgdgdggdgdgddgdhdhdhdhdhddgghdhdgdhdhdhhdhdhdhhdgdgdhdgdgdhdhdgfhfhdv dvdvvvdvdvdvdvddvdvfvdvfgddgfvvgdhhdvdvdvdgfvdhfdvdddhdhfh ddhfhdddhdhhdhfhfhfhhdhdhdhvffv
What is the V2O5 coefficient??
Answer:
1235
Explanation:
if thers a a guess in that number
The compound V₂O₅ has a Seebeck coefficient at a temperature of 50 °C of -990 μV/K.
What is a compound?Compound is defined as a chemical substance made up of identical molecules containing atoms from more than one type of chemical element.
Molecule consisting atoms of only one element is not called compound.It is transformed into new substances during chemical reactions. There are four major types of compounds depending on chemical bonding present in them.They are:
1)Molecular compounds where in atoms are joined by covalent bonds.
2) ionic compounds where atoms are joined by ionic bond.
3)Inter-metallic compounds where atoms are held by metallic bonds
4) co-ordination complexes where atoms are held by co-ordinate bonds.
They have a unique chemical structure held together by chemical bonds .Compounds have different properties as those of elements because when a compound is formed the properties of the substance are totally altered.
Learn more about compounds,here:
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