Answer:
75603.86473 K
Explanation:
Given that:
The 1st excited electronic energy level of He atom = 3.13 × 10⁻¹⁸ J
The objective of this question is to estimate the temperature at which the ratio of the population will be 5.0 between the first excited state to the ground state.
The formula for estimating the ratio of population in 1st excited state to the ground state can be computed as:
[tex]\dfrac{N_2}{N_1} = e ^{^{-\dfrac{(E_2-E_1)}{KT}}} = e ^{^{-\dfrac{(\Delta E)}{KT}}}[/tex]
From the above equation:
Δ E = energy difference = 3.13 × 10⁻¹⁸ J
k = Boltzmann constant = 1.38 × 10⁻²³ J/K
[tex]\dfrac{N_2}{N_1} = 0.5[/tex]
Thus:
[tex]0.05 =e^{^{ -\dfrac{3.13 \times 10^{-18} \ J}{1.38\times 10^{-23 \ J/K}\times T}}}[/tex]
[tex]In (0.05) = { -\dfrac{3.13 \times 10^{-18} \ J}{1.38\times 10^{-23 \ J/K}\times T}}}[/tex]
[tex]-3.00 = { -\dfrac{3.13 \times 10^{-18} \ J}{1.38\times 10^{-23 \ J/K}\times T}}}[/tex]
[tex]-3.00 = -226811.5942 \times \dfrac{1}{T}[/tex]
[tex]T = \dfrac{-226811.5942}{-3.00 }[/tex]
T = 75603.86473 K
In the US, nutritional energy is reported in Calories (Cal). One nutritional Calorie is equal to one kilocalorie (kcal). If a food package reports 250.0 Calories (Cal) per serving, how many calories (cal) are in each serving?
Answer:
2.500 × 10⁵ cal
Explanation:
1kcal= 1000 cal
From the analysis, the number of calories in each serving of a food with 250 Calories would be 250,000 calories.
According to the illustration:
1 Calories = 1 kilocalories
The food package reports 250 Calories
Hence, 250 Calories = 1 x 250 kilocalories
= 250 kilocalories
According to metrics, 1 kilocalories = 1,000 calories
Thus, 250 kilocalories = 250 x 1000 calories
= 250,000 calories
More on unit conversion can be found here: https://brainly.com/question/19420601
I NEED HELP ASAP PLEASE I BEG
with what?..................
If a neutral atom has 49 protons, how many electrons does it have?
What is the reason for the trend in lonization Energy? Select all that apply.
A. larger atomic mass number
B. number of energy levels around the nucleus C. number of valence electrons.
D. number of protons in the nucleus
E. number of neutrons in the nucleus
Answer:
Explanation:
A, D,E and B i think is the correct answers
Please i really need help
it's due today
Answer:
coke and mentos are basically just a small scale replica
Explanation:
True or false?
An apple, potato, and onion all taste the same if you eat them with your nose plugged.
Answer:
Its true I think but I may be wrong lol
Answer:
An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged
Explanation:
y e s
Please it's due today
Answer:
The answer is the second one
Lying in bed you notice that you get cold every time your brother opens the door. This is most closely associated with which step in the scientific method?
Answer:
Making an observation100% sure about that....just believe me
Hope u the best and hope that helps
How many moles of hydrogen are present in 5.30 moles of C5H10O2, propyl acetate, the compound that provides the odor and taste of pears.
Note the type of problem this is - you are being asked to relate moles of an element to 1 mole of a compound (subscripts and moles).
a. 10.6
b. 5.30
c. 6.02 x 1023
d. 53.0
Answer:
Option D. 53 moles.
Explanation:
The following data were obtained from the question:
Number of mole of C5H10O2 = 5.3 moles
Number of mole of Hydrogen in 5.3 moles of C5H10O2 =?
From the chemical formula of propyl acetate, C5H10O2,
1 mole of C5H10O2 contains 10 moles of H.
Therefore, 5.3 moles of C5H10O2 will contain = 5.3 × 10 = 53 moles of H.
Thus, 5.3 moles of C5H10O2 contains 53 moles of H.
An electron in the first energy level of the electron cloud has
an electron in the third energy level.
Answer: A LOWER ENERGY
Explanation:
did the test
Answer:
A lower energy!
Explanation:
I know this is not much of an explanation but I took the test i hope you have an amazing day afternoon or night! Hope this helps :3
Name something that has zero thermal energy.
Answer:
When all molecules in a system stop moving completely, there is zero thermal energy
Explanation:
It is impossible to reach though
The volume of a gas decreases to half of its original volume, but the gas maintains the same
number of moles and temperature. According to the ideal gas law, what will most likely
happen to the pressure?
A. It will double.
B. It will decrease.
C. It will increase slightly.
D. It will remain the same.
Answer:
c
Explanation:
it will slightly increase
Answer:
A
It will double
How do the chemical reactions in this lab activity compare to nuclear reactions, such as fission and fusion?
The chemical reaction has been the low energy reaction containing electrons rearrangement, while nuclear reactions have been the higher energy reactions with change in nuclei.
What are nuclear reactions ?The term nuclear reactions is defined as when there has been the including the change in the nuclei of the atom. However, the reaction has been known as the chemical reaction when the change has been processed in the electrons with the rearrangement.
The nuclear reactions have made up of a more amount of energy to be liberated, while the amount of energy included in the chemical reaction has been smaller.
Thus, the chemical reaction has been the low energy reaction including electrons rearrangement, while nuclear reactions have been the high energy reactions with change in nuclei.
For more information about the nuclear reactions, refer to the link:
https://brainly.com/question/16526663
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Chemistry of Life Practice Active 8 1 What type of organic compound is used for building cell parts?
Answer:
Carbohydrates
Explanation:
Give the location in the Periodic Table of Elements that have the same number of valence electrons.
All groups (columns) have the same number of valence electrons
All periods (rows) have the same number of valence electrons
All groups (columns), with the exception of Helium in the Noble Gases, have the same number of valence electrons
There is no trend found on the periodic table
Answer:
• All groups (columns) have the same number of valence electrons
Explanation:
Every group or column have the same number of valence electrons as a suprise. Every column is aligned in this way.
Answer:
all members within any group
Explanation:
Dinitrogen tetraoxide, a colorless gas, exists in equilibrium with nitrogen dioxide, a reddish brown gas. One way to represent this equilibrium is:
The question is incomplete, the complete question is shown in the image attached
Answer:
F
T
Explanation:
From the equilibrium equation;
N2O4(g) ⇄NO2(g)
We must have to remember that;
1) At equilibrium, the concentration of the species on both sides of the reaction equation may not necessarily be the same but must be held at a constant value because the rate of forward reaction equals the rate of reverse reaction.
2) The rate of forward reaction must equal the rate of reverse reaction.
If the rate of forward reaction is k1 and the rate of reverse reaction is k2. Then it follows that at equilibrium k1 = k2.
What is the Dependent variable?
Explanation:
Just like an independent variable, a dependent variable is exactly what it sounds like. It is something that depends on other factors. For example, a test score could be a dependent variable because it could change depending on several factors such as how much you studied, how much sleep you got the night before you took the test, or even how hungry you were when you took it. Usually when you are looking for a relationship between two things you are trying to find out what makes the dependent variable change the way it does.
In this periodic table, which type of element is shown in green boxes?
A. Metalloids
B. Nonmetals
C. Noble gases
D. Metals
Answer: A
Explanation:
Metalloids
fireworks convert chemical energy into what kind of energy
Answer:
Kinetic energy
Explanation:
Fireworks convert chemical energy into kinetic energy to send them flying upward. Hope it is correct!
If a reaction generated 3.5 g of H2O how many moles of water were formed?
Answer:
0.19 mol H₂O
General Formulas and Concepts:
Chem
Reading a Periodic TableUsing Dimensional AnalysisExplanation:
Step 1: Define
Given: 3.5 g H₂O from RxN
Step 2: Define conversions
Molar Mass of H - 1.01 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of H₂O - 2(1.01) + 16.00 = 18.02 g/mol
Step 3: Convert
[tex]3.5 \ g \ H_2O(\frac{1 \ mol \ H_2O}{18.02 \ g \ H_2O} )[/tex] = 0.194229 mol H₂O
Step 4: Check
We are given 2 sig figs. Follow sig fig rules.
0.194229 mol H₂O ≈ 0.19 mol H₂O
what is the the correct equation for water gas
Answer:
Water-gas A mixture of carbon monoxide (CO) and hydrogen (H2) produced by passing steam over red-hot coke using the endothermic reaction C + H2O → CO + H2.
What mass of solid aluminum hydroxide is produced when 50.0 mL of 0.20 M aluminum nitrate is added to 200.0 mL of 0.100 M potassium hydroxide?
Answer:
0.52g of Al(OH)₃
Explanation:
The reaction of aluminium nitrate, Al(NO₃)₃, reacts with KOH, as follows:
Al(NO₃)₃ + 3KOH → Al(OH)₃ + 3 KNO₃
That means 1 mole of aluminium nitrate reacts with 3 moles of potassium hydroxide.
To find moles of aluminium hydroxide we need to determine the limiting reactant finding moles of each reactant:
Moles aluminium nitrate:
0.050L * (0.20mol / L) = 0.01 moles Al(NO₃)₃
Moles KOH:
0.200L * (0.100mol / L) = 0.02 moles of KOH
Thus, for a complete reaction of 0.02 moles of KOH are needed (Using the chemical equation)
0.02 moles of KOH * (1 mol Al(NO₃)₃ / 3 mol KOH) = 0.0067 moles of Al(NO₃)₃.
As there are 0.01 moles of Al(NO₃)₃, this is the excess reactant and KOH is the limiting reactant.
The 0.02 moles of KOH produce:
0.02 moles of KOH * (1 mol Al(OH)₃ / 3 mol KOH) = 0.0067 moles of Al(OH)₃
In mass (Using molar mass of Al(OH)₃: 78g/mol):
0.0067 moles of Al(OH)₃ * (78g/mol) =
0.52g of Al(OH)₃Based on molecular orbital theory, the only molecule in the list below that has unpaired electrons is __________.a) C2b) N2c) F2d) O2e) Ne2
Answer:
B.
Explanation:
ive done this before trust
what are the existing evidences to support the existence of pangea?
salamat.
Fossil evidence for Pangaea includes the presence of similar and identical species on continents that are now great distances apart.
Which elements-O2, Rb, Sb, Pt, Y, Sm, Mn, Rh, Sn, Li-will react (a) with a solution of I to generate I2; (b) with a solution of Ag' to generate Ag; and (c) with a solution of Nat to generate Na?
Answer:
a) O2, Pt, Rh
b) Rb, Y, Sm, Mn, Sn, Li
c)Rb
Explanation:
We must consider the reduction potentials of each of the species in the question.
In (a) above, all the elements whose reduction potential is higher than the redox potential for the oxidation of I^- will react with a solution of I^- to generate I2 as shown above.
In (b) above, all the strong reducing agents can donate electrons to Ag^+ and reduce it to Ag as shown above.
In (c) Rb has a more negative reduction potential than sodium hence it can react with a solution of sodium salt to generate sodium metal.
A gram of gasoline produces 45 kJ of energy when burned. Gasoline has a density of 0.77 g/mL. How would you calculate the amount of energy produced by burning 48 L of gasoline?
The energy produced in the burning of gasoline = 45 kJ/g. So, amount of energy produced by burning 48 L gasoline = 45 kJ/g×36960 g = 1663200 kJ.
How is filtration done?
What is the difference between residue and filtrate?
Answer:
residue is whatever remains after something else has been removed while filtrate is the liquid or solution that has passed through a filter, and which has been separated from the filtride.
filtration id done by placing a filter paper on the beaker or container then pour the filtride then let it settle and it will pass through and you will have the fitrate and residue
Explanation:
describe the dual nature of electrons (give an example)
Answer:
In 1924, the French physicist, Louis de Broglie suggested that if light has electron, behaves both as a material particle and as a wave. According to this theory, small particles like electrons when in motion possess wave properties.
Explanation:
examples
This can be derived as follows according to Planck’s equation, E = hv = hc /λ ∴ v=c/λ(energy of the photon (on the basis of Einstein’s mass energy relationship) E = mc2
( If Bohr’s theory is associated with de-Broglie’s equation then wave length of an electron can be determined in bohr’s orbit and relate it with circumference and multiply with a whole number 2πr = nλ or λ = (2πr/2π) From de-Broglie equation, λ = (h/mv).
Which term best describes the materials that make up rocks?
sand left by erosion
compressed magma
a mixture of minerals
layers of lava
Answer:
is c a mixture of minerals
Explanation:
The rate constant for the radioactive decay of tritium 3H is 0.056 1/yr. The percentage of tritium remaining after 50 years is:_________
Answer:
6.05%
Explanation:
From the question given above, the following data were obtained:
Decay constant (K) = 0.0561 /yr
Time (t) = 50 years
We can obtain the percentage of tritium remaining after 50 years by using the following formula:
Log (N₀/N) = kt /2.303
NOTE:
N₀ is the original amount.
N is the amount remaining.
K is the decay constant.
t is the time
Log (N₀/N) = (0.0561 × 50) /2.303
Log (N₀/N) = 2.805/2.303
Log (N₀/N) = 1.218
Take the anti log of 1.218
(N₀/N) = anti log (1.218)
(N₀/N) = 1.218
N₀/N = 16.52
Invert and multiply by 100 to obtain the percentage.
N/N₀ = 1/16.52 × 100
N/N₀ = 6.05%
Thus, the percentage of tritium remaining after 50 years is 6.05%
Answer:
6.08% remains after 50 years
Explanation:
The radioactive decay follows the equation:
Ln[A] = -kt + Ln [A]₀
Where [A] is concentration of reactant after time t, [A]₀ is its initial concentration, k is rate constant and t is time.
Assuming its Initial concentration is 100%
Time is 50 yr
k is 0.056 yr⁻¹
And [A] is our incognite
Ln[A] = -0.056 yr⁻¹*50yr + Ln [100%]
ln[A] = 1.805
[A] =
6.08% remains after 50 years