Characteristic orange light produced by sodium in a fl ame is due to an intense emission called the sodium D line, which is actually a doublet, with wavelengths (measured in vacuum) of 589.157 88 and 589.755 37 nm. The index of refraction of air at a wavelength near 589 nm is 1.000 292 6. Calculate the frequency, wavelength, and wavenumber of each component of the D line, measured in air.
Answer:
a. i. 5.092 × 10²⁰ Hz ii. 588.98554 nm ii. 10667809.11 rad/m
b. i. 5.087 × 10²⁰ Hz ii. 589.58286 nm iii. 10657001.3 rad/m
Explanation:
refractive index, n = λ/λ' where λ = wavelength in vacuum = and λ' = wavelength in air
a. For λ = 589.15788 nm,
i. Frequency,
f = c/λ where c = speed of light in vacuum = 3 × 10⁸ m/s and λ = 589.15788 nm = 589.15788 × 10⁻⁹ m
So, f = 3 × 10⁸ m/s ÷ 589.15788 × 10⁻⁹ m
= 0.005092 × 10¹⁷ /s
= 5.092 × 10²⁰ /s
= 5.092 × 10²⁰ Hz
ii. Wavelength,
Since n = λ/λ' where λ = wavelength in vacuum = and λ' = wavelength in air
and n = 1.0002926
λ' = λ/n
= 589.15788 nm/1.0002926
= 588.98554 nm
iii. Wave number, kk = 2π/λ'
= 2π/588.98554 nm
= 0.01066780911 rad/nm
= 0.01066780911 rad/nm × 10⁹ nm/1m
= 10667809.11 rad/m
b. For λ = 589.755 37 nm.,
i. Frequency,
f = c/λ where c = speed of light in vacuum = 3 × 10⁸ m/s and λ = 589.755 37 nm. = 589.755 37 × 10⁻⁹ m
So, f = 3 × 10⁸ m/s ÷ 589.755 37 × 10⁻⁹ m
= 0.005087 × 10¹⁷ /s
= 5.087 × 10²⁰ /s
= 5.087 × 10²⁰ Hz
ii. Wavelength,
Since n = λ/λ' where λ = wavelength in vacuum = and λ' = wavelength in air
and n = 1.0002926
λ' = λ/n
= 589.755 37 nm./1.0002926
= 589.58286 nm
iii. Wave number, kk = 2π/λ'
= 2π/589.58286 nm
= 0.0106570013 rad/nm
= 0.0106570013 rad/nm × 10⁹ nm/1m
= 10657001.3 rad/m
The heat capacity of aluminum is 0.900 J/gºC. a. How much energy is needed to raise the temperature of an 8.50 x 102g block of aluminum from 22.8°C to 94.6°C?
Recall the heat capacity equation:
q = mc∆T
We're given mass, specific heat capacity, as well as the change in temperature. All we need to do is plug the numbers into the variables and we'll have our answer!
Although this question doesn't try to trick you, more often than not questions regarding energy change will attempt to throw you off with specific heat capacity. It's extremely important to note the units of the specific heat capacity and ensure that the numbers you use are in those units. As an example, the specific heat capacity might be given to you in J/mol*K - in this case, you'd have to do some unit conversions with your given data in order to fit all the numbers. In this question, we're given the specific heat capacity in J/gºC, so we don't need to change anything since all of our data is already in these units.
Anyways, back to the actual question:
q = mc∆T
q = (8.50 * [tex]10^{2}[/tex]) * (0.900) * (94.6 - 22.8)
q = 54927 (J)
Remeber to include significant figures:
54927 = 5.49 * 10^4 (J)
The required energy is 5.49 * [tex]10^{4}[/tex] Joules, or 5.49 * [tex]10^{1}[/tex] kJ
Let me know if you need any of my work to be explained!
- Breezeツ
Which of the following statements are true about a strong base and a weak base at a pH of 11?
A. The weak base will require less HCl to bring the pH to 7 than the strong base.
B. The strong base will require less HCl to bring the pH to 7 than the weak base.
C. Both bases require the same amount of HCl to reach pH 7 because they are both at the same initial pH.
D. HCl will not bring the pH of either solution to pH 7.
Answer:
A, C, D
Explanation:
What is the number of moles in 15.0 g AsH3?
O 5.2 mol
O 1200 mol
O 0.44 mol
O 0.19 mol
Answer:
n = 0.19 mol
Explanation:
Given mass = 15 g
The molar mass of AsH₃ = 77.94 g/mol
We need to find the number of moles in 15 g of AsH₃. We know that,
No. of moles = given mass/molar mass
[tex]n=\dfrac{15}{77.94 }\\\\n=0.19\ mol[/tex]
So, there are 0.19 g/mol. Hence, the correct option is equal to 0.19 mol.
Weight is the measure of gravity on an object measured by a weight in Newtons. Weight changes if gravitational force changes.
Mass is the amount of kilogram in an object measured by a __________ in grams and does not change…it stays the _________.
Mass is an intrinsic property of matter and is measured in kilograms. The mass of a bird is a constant. A 15-gram bird is 15 grams, whether measured on the Earth, the Moon, or Mars. Weight is a measure ofthe force of gravity on a physical object and is measured in newtons.
which one is correct for #4 ??
Answer:
The answer of this question is A
Answer: B is the right
Explanation:
One advantage to using nuclear power is —
it produces no air pollution
it is hard to store and dispose of the waste
the expense of constructing nuclear reactors
the threat of an accident
Answer:
it produces no air pollution
Atomic Size: Determine which of the following element pairs is the larger one
1. Carbon or Fluorine
2. Iodine or Fluorine
3. Krypton or Argon
4. Hydrogen or Potassium
how to obtain pure aluminium oxide from sodium aluminate. pls help.
Answer:
By Bayer process.
Explanation:
In the Bayer process, bauxite ore is heated in a pressure vessel along with a sodium hydroxide solution (caustic soda) at a temperature of 150 to 200 °C. At these temperatures, the aluminium is dissolved as sodium aluminate (primarily [Al(OH)4]−) in an extraction process.
A truck has a kinetic energy of 1200j and is traveling at 9 m/s what is the truck mass
Answer:
Mass of truck = 29.62 kg (Approx.)
Explanation:
Given:
Kinetic energy = 1200 J
Speed of truck = 9 m/s
Find:
Mass
Computation:
The kinetic energy of a thing is the force that has attributable to its movement in physics.
Kinetic energy = [1/2][m][v]²
1,200 = [1/2][m][9]²
1,200 = [1/2][m][81]
Mass of truck = 29.62 kg (Approx.)
What types of elements [metals/nonmetals] are found in each of the compounds?
Not a simple answer please
Explanation:
List of All Elements That Are Nonmetals
Hydrogen (sometimes)
Carbon.
Nitrogen.
Oxygen.
Phosphorus.
Sulfur.
Metals:-
Gold.
Silver.
Iron.
Copper.
Nickel.
Aluminum.
Mercury( Liquid metal)
Titanium.
Fluorine.
Question 1 (1 point) How many stars are in our solar system? A. About 20.000 B. About 300,000 C. One D. About 5,000
Answer:
C. one star
Explanation:
Of course our solar system has one unique star which is the sun while others have atleast two which are called binary solar
Which indicator would show a pH change from 6 to 7?
A. Red litmus indicator
B. Methyl red indicator
C. Phenol red indicator
D. Blue litmus indicator
Answer:
c
Explanation:
1. litmus paper is used when showing a change between a greater range in ph levels - so A and D are automatically a no.
2. methyl red is used to show a range in ph levels between 4.8-6
3. Option C is the only one left so im going to assume its C because its definitely not A, B, or D
If you initially have a gas with a pressure of 0.950 atm and a temperature of 35 °C and you heat it to 65 °C, what is the new pressure if volume and moles are held constant? (P2 = 1.04 atm)
Explanation:
fgIf the piston moves so as to increase the pressure of the gas to 2.94 atm, ... new volume of the cylinder? ... A gas has a pressure of 699.0 mm Hg at 40.0°C. What is the temperature (in C) ...
What is the relationship between the valence electrons of an atom and the chemical bonds the atom can form?
Answer:
Valence electrons are outer shell electrons with an atom and can participate in the formation of chemical bonds. In single covalent bonds, typically both atoms in the bond contribute one valence electron in order to form a shared pair. The ground state of an atom is the lowest energy state of the atom.
Stoichiometry
1. Based on the equation, Mg+2NaF => MgF2 + 2Na , if 23.56 grams of magnesium reacts with sufficient sodium
fluoride, how many grams of sodium will be produced?
Since we have sufficient sodium fluoride (NaF), the magnesium (Mg) will be our limiting reactant, and we will use its coefficient in the balanced equation to determine our molar ratio between the product of interest which, in this case, is sodium (Na).
We are given the mass of magnesium, 23.56 grams, which we must convert to moles by dividing the mass by the molar mass of magnesium: (23.56 g)/(24.305 g/mol) = 0.9693 mol Mg.
According to the balanced equation given, the molar ratio between sodium and magnesium is 2:1. That is, for every 2 moles of Na that are produced, one mole of Mg is consumed or reacted. The upshot is that the number of moles of sodium produced will be double the number of moles of Mg reacted. Since we have 0.9693 moles of Mg available to react, we will obtain (0.9693 mol Mg)(2 mol Na/1 mol Mg) = 1.939 mol Na.
Finally, we multiply our moles of sodium by the molar mass of sodium to get the mass: (1.939 mol Na)(22.99 g/mol) = 44.57 grams Na.
So, 44.57 grams of sodium will be produced.
The answer is given to four significant figures.
9. What happens to the cell outside of the nucleus when the virus has been copied so many times? a. The cell fights back b. The cell gets help from its neighbor cells C. The cell gets help from white blood cells d. The cell is destroyed
Answer: it think the answer is c.) The cell gets help from white blood cells or b.) The cell gets help from its neighbor cells.
Explanation:
why should atom or ions join together to form compounds?
Answer:
while atoms form together, they percentage their outermost electrons to create more sustainable strength states. This sharing bonds the atoms into an ionic shape or a molecule
Explanation:
i hope this help a little
Which of Graphs 1 correctly represents the relationship between the volume and Kelvin temperature of a gas?
Answer:
B
Explanation:
Pressure is directly proportional to temperature
What is the Ka of a 0.0981 M
solution of hydrocyanic acid
(HCN) with a pH of 6.00?
Ka = [?] x 10!?)
Answer:
Attached picture
Ka = [?] x 10
1.02 x 10^-11 = [?] x 10
[?] = 1.02 (I'm assuming you're asking this)
(If not then divide the 10)
Answer:
The answer is 1.02x10^-11
Explanation:
Fill in the box 1.02 and then -11
If five gases in a cylinder EACH exert a partial pressure of 2.5 atm, what is the total pressure in the cylinder? Be sure to bubble your answer on the answer sheet.
Answer:
16 atm
Explanation:
I
11122
11 / 22
=>
Which of the following hydrogen ion concentrations represents a solution with acidic
properties?
A
?
1 x 10-8 M
В.
?
1 x 10-2 M
C
1 x 10-11 M
D
1x 10-13 M
Activity Index
A
Answer:
A
Explanation: 11/22
Which boundary or zone adds new material to the lithosphere (the hard outer crust of the Earth)
Answer:Divergent Boundaries(or Boundary)
Explanation:took the test and got it right
How many molecules are in 3.01 g of H2O
A. 0.167 molecules
B. 54.18 molecules
C. 1.01x10^23 molecules
D. 6.022x10^23
Answer:
Option C
Explanation:
No. of Molecules=(Given Weight/Molar weight)*Avagadro No.
Given weight of H2O=3.01g
Molar weight of H2O=18g
On applying the formula, we get:
No. of Molecules=(3.01/18)*6.023*10²³=1.01*10²³
this is due in five mintues please help
Answer:
5
Explanation:
Na, N, O, O, O
Is combining ammonium chloride and water a physical or chemical change
why an indicator is a necessary part of the titration experiment?
Answer:
In a titration, you determine an unknown concentration of a sample by adding a second reactant of known concentration. In many titrations, you use a chemical called an indicator, which lets you know when the titration finishes.
Explanation:
Please Help ASAP!!! Will mark Brainliest!!!
A 35 kg child is standing in a 70 kg boat resting on the water. The child jumps forward, away from the boat, pushing with a force of 500 N. After the jump, the boat moves backward.
What does this scenario show?
A. The boat does not exert a force to balance the 500 N force, causing the boat to move.
B. The water creates a frictionless surface, causing the boat to move without an action force.
C. The boat has a greater mass than the child but reacts to an action force.
D. The water beneath the boat absorbs the 500 N force but keeps the boat afloat.
Answer:
A
Explanation:
the boat does not have a force to counter act the boys it must give which means it moves cause it is one something that is not as dense as the boy (I THINK)
A car accelerates away from the starting line at 3.6 m/s2 and has the mass of 2400 kg. What is the net force acting on the vehicle?
__ Newtons ??
Answer:
8640 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
net force = 2400 × 3.6
We have the final answer as
8640 NHope this helps you
Which of the following is another term for eruptions of gas on the sun's surface?
A. nuclear fusion
B. sunspots
C. coronas
D. solar flares
Answer:
D
Explanation: