Answer:
Bohr's Model postulates-
I postulate - The electrons in an atom orbit around the nucleus in definite circular paths called orbits or shells.
II Postulate - Each shell or orbit represents a specific amount of energy.
III Postulate - By emitting or absorbing energy, an electron may shift from one stationary energy orbit to another.
Three main Limitations -
1- It adjusts to the hydrogen atom's spectrum but not to the spectra of other atoms.
2 - In the definition of the electron as a tiny particle that spins around the atomic nucleus, the wave properties of the electron are not described.
3- Bohr is unable to understand why classical electromagnetism is inapplicable to his model. That is why, when electrons are in a stationary orbit, they do not emit electromagnetic radiation.
Explanation:
About Bohr's postulates-
1 - The electron spins in circling circles around the nucleus, emitting no energy. The orbital angular momentum is constant in these orbits.
Only certain radii of orbits, corresponding to certain given energy levels, are required for electrons in an atom.
2- Not every orbit is possible. However, whenever an electron is in a legal orbit, it is in a state of unique and constant energy and does not emit energy (stationary energy orbit).
For example - The energies allowed for electrons in the hydrogen atom are given by the following equation: The Rydberg constant for the hydrogen atom is [tex]-2.8\times10^-^1^8[/tex] in this equation, and n = quantum number will range from 1 to ∞. For each of the values of n, the electron energies of a hydrogen atom produced by the above equation are negative. As n rises, the energy becomes less negative and thus rises.
3- By emitting or absorbing energy, an electron may shift from one stationary energy orbit to another.
The energy difference between the two states would be equal to the energy released or consumed. This energy E is in the form of a photon, and it can be measured using the following formula:
[tex]E=h[/tex][tex]v[/tex]
E is the energy (absorbed or emitted) in this equation, and h is the Planck constant (its value is [tex]6.63\times10^-^3^4 Js[/tex]) and v denotes the frequency of light, which is calculated in 1/ s.
The law of conservation of mass is correctly demonstrated in which statement about cellular respiration
Answer:
The total mass of glucose and oxygen is equal to the total mass of carbon dioxide and water.
Explanation:
:)
What type of chemical bond holds 2Na+ and O2-together in
Na20?
a Metallic Bond
blonic Bond
C Molecular Bond
d Van der Waals' force
e Covalent Bond
Answer:
Covalent bond.
Explanation:
It involves sharing electrons equally between both molecules.
(b) The heating element is made from metal. Write down two properties
of the metal so that it can be used in the heating element.
1.
[2]
2.
(c) Plastic and stainless steel are synthetic materials. What is meant by
synthetic?
[1]
Answer:
Two properties of heating metal
1.high melting points.
2.malleable
What is meant by synthetic?
1.made of artificial material, not natural items, synthetic is made up of chemical synthesis. (synthetic compound, synthetic drug, synthetic material)
Explanation:
1.They are solid (with the exception of mercury, Hg, a liquid).
2 They are malleable (they can be easily hammered into very thin sheets).
What are some differences between earth and mars
Oki,
1. Earth is third planet away from the Sun whiles Mars is the fourth planet away from the Sun.
2.. Earth takes 365 days to revolve around the Sun whiles Mars takes 687 days to do so.
3. Earth is the fifth largest planet in the Solar System whiles Mars is the second smallest planet.
4. Mars is reddish in colour but Earth is not
5. About 70% of the earth is covered with water but Mars is just covered with bare dust and rocks.
Hope this is enough
A wave is a disturbance that carries...
Which terms below describes polymer that stretch
A. Elastomers
B. Thermosets
C. Polypropylene
D. Thermoplastic
2. Which of the following is most likely to to cause the extinction
of a species?
A. Mutation
B. A changing environment
C.natural selection
D. Genetic variation
Answer:
a change of environment
In the equation:
2H2 + O2 --> 2H2O
What mass of Hydrogen Gas will completely react with 4 moles of Oxygen gas
(Hint: going from moles to mass of another compound)
A)8 g
B)16 g
C)24 g
Answer:
B) 16 g
Explanation:
2H₂ + O₂ → 2H₂OFirst we convert 4 moles of O₂ into moles of H₂, using the stoichiometric coefficients of the balanced reaction:
4 mol O₂ * [tex]\frac{2molH_2}{1molO_2}[/tex] = 8 mol H₂Finally we convert 8 moles of H₂ into grams, using its molar mass:
8 mol H₂ * 2 g/mol = 16 gThus, the correct answer is option B).
The rate constant of a reaction is 6.4 × 10−3 s−1 at 25°C, and the activation energy is 33.6 kJ/mol. What is k at 75°C? Enter your answer in scientific notation.
Answer:
k₂ = 5 x 10⁻² s⁻¹
Explanation:
Using the Clausis - Clapyron Equation ...
ln(k₁/k₂) = ΔH/R(T₁-T₂/T₁·T₂) => lnk₂ = lnk₁ + ΔH/R(T₁-T₂/T₁·T₂)
k₁ = 6.4 x 10⁻³s⁻¹
ΔH = 33.6 Kj/mole
R = 0.008314 Kj/mol·K
T₁ = 25°C = 298K
T₂ = 75°C = 348K
lnk₂ = ln(6.4 x 10⁻³s⁻¹) + (33.6kj/mol·K/0.008314Kj/mol·K)·[(348K - 298K)/(348K)(298K)] = -3.10s⁻¹
k₂ at 75°C = exp(-3.10) = 5 x 10⁻²s⁻¹ (faster k-value at higher temp)
What volume in L of a 0.724 M Nal solution contains 0.405 mol of Nal?
Answer:
0.559 L
Explanation:
Step 1: Given data
Moles of sodium iodide (n): 0.405 molMolar concentration of sodium iodide (M): 0.724 M (0.724 mol/L)Step 2: Calculate the volume of solution (V)
The molarity is equal to the moles of solute divided by the liters of solution.
M = n/V
V = n/M
V = 0.405 mol/(0.724 mol/L) = 0.559 L
The volume in Litres of a 0.724 M Nal solution that contains 0.405 mol of Nal is 0.56L.
HOW TO CALCULATE VOLUME:
The volume of a solution can be calculated by dividing the number of moles by the molarity as follows:Volume = no. of moles ÷ molarityAccording to this question, 0.724 M sodium iodide (NaI) solution contains 0.405 mol of Nal, the volume can be calculated as follows:Volume = 0.405mol ÷ 0.724MVolume = 0.56 LitresTherefore, the volume in Litres of a 0.724 M Nal solution that contains 0.405 mol of Nal is 0.56L.Learn more at: https://brainly.com/question/15626439?referrer=searchResults
A gas that exerts a pressure of
15.6 psi in a container with a volume of
L will exert a pressure of
25.43 psi when transferred to a
container with a volume of 1.895 L.
Answer:
3.1L
Explanation: using Boyle's law p1v1=p2v2
p1=15.6,v1=?,p2=25.43,v2=1.895
manipulate the formula to favor so to find v1 the formula would be
p2v2/p1
25.43*1.895\15.6=3.1L
A student claims that signals transmitted by wireless computer networks are more beneficial than signals transmitted by other devices. Which statement supports the student’s claim?
im giving brainliest and 11 points
Answer: The wireless signals can carry large amounts of data at high radio frequencies.
Explanation: the others don’t specify the kind of signal
How does the Sun get energy?
Answer:
Nuclear fushion
Explanation:
The sun generates energy from a process called nuclear fusion. During nuclear fusion, the high pressure and temperature in the sun's core cause nuclei to separate from their electrons
Calculate the value of the equilibrium constant, c, for the reaction
Q(g)+X(g)=2M(g)+N(g)
given that
M(g)=Z(g) c1=3.97
6R(g)=2N(g)+4Z(g) c2=0.523
3X(g)+3Q(g)=9R(g) c3=11.8
Question is asking for c
a solution is prepared by dissolving 4.85 g of HCl into enough water to make 2.50 L of a solution
Answer:
0.0532 M
Explanation:
Just did the test :)
type of environmental factors such as temperature or amount of light that might affect an organism's phenotype is___________
convert 25.2 ml to dl
Answer:
0.252
Explanation:
Which of the following chemical equations is balanced correctly?
Cl2 + NaI—> 2 NaCl + 12
B202 + 2C—>B4C +CO
C6H6 + 02–>2C02 + 3H20
CS2 + 3C12–>CCl4 +S2Cl2
what are the main forces that operate between nonpolar molecules
Answer:
Van der Waals forces
Explanation:
Answer:
Dispersion
Explanation:
They said it was the answer.
A paleontologist finds a fish fossil in a desert. What might the paleontologist learn from this?
Answer:
sometime back there might be a water body there
Answer:
Paleontologists can identify organisms that may be ancient relatives of those living today. By looking at fossils from the same layer of rocks, they can also suggest how these organisms lived together in their ancient habitat.
Also, he/she can find out that there was water there millions of year ago.
A 3.6 g sample of iron (III) oxide reacts with sufficient aluminum to be entirely used up.
How much iron is produced?
Answer:
0.046 mol
Explanation:
Step 1: Write the balanced equation
Fe₂O₃ + 2 Al ⇒ 2 Fe + Al₂O₃
Step 2: Calculate the moles corresponding to 3.6 g of Fe₂O₃
The molar mass of Fe₂O₃ is 159.69 g/mol.
3.6 g × 1 mol/159.69 g = 0.023 mol
Step 3: Calculate the moles of Fe produced from 0.023 moles of Fe₂O₃
The molar ratio of Fe₂O₃ to Fe is 1:2.
0.023 mol Fe₂O₃ × 2 mol Fe/1 mol Fe₂O₃ = 0.046 mol Fe
A sample of nitrogen gas has a temperature of 22.7oC when the volume of the container is 12.2L and it is under 150.4kPa of pressure. What temperature, in Kelvin, would the gas need to be in order to occupy a 9.7L container at 101.3kPa? Show all your work and round your answer to the hundredths place.
22.7 degrees Celsius = 22.7 + 273 = 295.7 K
[tex]\frac{(12.2)(150.4)}{295.7}=\frac{(9.7)(101.3)}{T_{2}} \\ \\ \frac{295.7}{(12.2)(150.4)}=\frac{T_{2}}{(9.7)(101.3)} \\ \\ T_{2}=\frac{(295.7)(9.7)(101.3)}{(12.2)(150.4)} \approx \boxed{158.35 \text{ K}}[/tex]
What is the term used for the elements and compounds after a chemical reaction takes place?
Answer: reactants.
Explanation:
To the right of the arrow we have the 'after' situation. This side represents the substances that we have after the reaction has taken place. They are called the products
gas laws escape room
Answer:
what are you asking
Explanation:
The gas laws are Boyle's law, Charles law, ideal gas law, and Gay-Lussac law.
What are the different gas laws?The first law is Boyle's law that states that at constant temperature, the pressure varies with volume of the gas.
The second law is Charles's law that states that at constant pressure, the volume of the gas is directly proportional to the temperature of the gas.
Above, both laws form the ideal gas law. PV = nRT.
Thus, the gas laws are Boyle's law, Charles law, ideal gas law, and Gay-Lussac law.
Learn more about gas laws
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help help plz what is the difference between normal and transition elements
Answer:
hope it helps you
mark me as brainliest!!
True or false. Compounds are two or more DIFFERENT elements.
A. True
B. False
Answer:
the answer is letter B,FALSE
Please help me with this
Answer:
C
Explanation:
Protons and neutrons!
Have a great day :))))
water is a ----------- natural resources
Answer:
True
Explanation:
what energy is watching tv
1.thermal
2.sound
3.light
4.electrical
5.mechanical
Answer:
4. electrical
Explanation:
The answer is electrical let me know if it's right
Use the References to access important values if needed for this question.
According to the following reaction, how many moles of sodium hydroxide will be formed upon the complete reaction of 0.263 moles
sodium with excess water?
2Na(s) + 2H, 0() 2NaOH(aq) + H2(g)
mol sodium hydroxide
Submit Answer
Retry Entire Group
2 more group attempts remaining
Answer:
0.263 mole of NaOH
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2Na + 2H₂O —> 2NaOH + H₂
From the balanced equation above,
2 moles of Na reacted to produce 2 moles NaOH.
Finally, we shall determine the number of mole of NaOH produced by the reaction of 0.263 mole sodium, Na. This can be obtained as follow:
From the balanced equation above,
2 moles of Na reacted to produce 2 moles NaOH.
Therefore, 0.263 mole of Na will also react to produce 0.263 mole of NaOH.
Thus, 0.263 mole of NaOH was obtained from the reaction.