Answer:
4.7 x 10^14 Hz
Explanation:
From Bohr's theory, the energy absorbed or emitted (ΔE) by an atom transiting from one energy level to another is given as;
ΔE = E4 - E2
Where;
E4 = energy corresponding to the energy level n=4
E2 = energy corresponding to the level n= 2
ΔE = (-2.10 x 10-19) - ( - 5.20 x 10-19)
ΔE =3.1 x 10-19
But
ΔE = hf
h = Plank's constant
f= frequency of photon absorbed
f = ΔE/h = 3.1 x 10-19/6.6 x 10-34
f = 4.7 x 10^14 Hz
‼️PLS HELP SCHOOL IS A NIGHTMAREE‼️
Which electromagnetic waves have the shortest wavelength and the highest frequency?
______ waves
Answer:gamma rays
Explanation: your welcome
If 8 moles of solute is dissolved in enough water to make 2 liters of solution, what is the molarity (M) of the
solution?
A 8M
B 4M
C 2M
D
16 M
Answer:
it will be 4M because molarity = no.of mole/volume
The molarity of the solution is 4 M.
What is molarity?The moles of a solute per liter of a solution is known as molarity, which is also defined as molar concentration of a solution.
Molarity can be calculated by using the following formula,
[tex]Molarity\;\\=\;\frac{Moles\; of\; the\; solute}{volume\; of\; the\; solution}\\\\= \frac{8\; mol}{ 2\;L} \\=\;4 \;mol/L\\=\;4\;M[/tex]
Hence the molarity of the solution comes out to be 4 M.
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Oxidation is now defined in terms of change of oxidation number. Explore how earlier definitions of oxidation and reduction may have led to conflicting answers for the conversion of P4 to H2PO2− and the way in which the use of oxidation numbers has resolved this.
Answer:
4
Explanation:
oxidation number resolved 4
The oxidation state of an element is calculated by subtracting and the total sum of oxidation states of all the individual atom (excluding the one that has to be calculated) from total charge on the molecule. Therefore, the oxidation state of phosphorous in H[tex]_2[/tex]PO[tex]_2[/tex]⁻ is +1.
What is oxidation state?Oxidation state of an element is a number that is assigned to an element in a molecule that represents the number of electron gained or lost during the formation of that molecule or compound.
P[tex]_4[/tex] [tex]\rightarrow[/tex] H[tex]_2[/tex]PO[tex]_2[/tex]⁻
Oxidation number of P=0
Oxidation number of P in H[tex]_2[/tex]PO[tex]_2[/tex]⁻
(+1)×2+ Oxidation number of P + (-2)2 = -1
2 + Oxidation number of P -4 = -1
Oxidation number of P= +1
Therefore, the oxidation state of phosphorous in H[tex]_2[/tex]PO[tex]_2[/tex]⁻ is +1. The oxidation state of phosphorous in P[tex]_4[/tex] is 0.
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Use the tabulated half-cell potentials to calculate ΔG° for the following balanced redox reaction. Pb2+(aq) + Cu(s) → Pb(s) + Cu2+(aq)
Answer:
90.71 KJ
Explanation:
From the reaction equation, lead is the cathode while copper was the anode.
Hence;
E°anode = +0.34V
E°cathode = -0.13 V
E°cell =E°cathode - E°anode
E°cell = -0.13 V - 0.34V
E°cell = -0.47 V
But;
ΔG° = -nFE°cell
n= number of electrons transferred = 2
F = Faraday's constant = 96500 C
E°cell = -0.47 V
ΔG° = -(2 * 96500 * (-0.47))
ΔG° = 90,710 J or 90.71 KJ
The standard Gibbs free energy for the reaction
Pb²⁺(aq) + Cu(s) → Pb(s) + Cu²⁺(aq) is 89.3 kJ/mol.
Let's consider the following redox reaction.
Pb²⁺(aq) + Cu(s) → Pb(s) + Cu²⁺(aq)
We can identify both half-reactions.
Reduction (Cathode): Pb²⁺(aq) + 2 e⁻ → Pb(s) E°red = -0.126 V
Oxidation (Anode): Cu(s) → Cu²⁺(aq) + 2 e⁻ E°red = +0.337 V
We can calculate the standard potential of the cell (E°cell) using the following expression.
E°cell = E°red,cathode - E°red,anode = -0.126 V - 0.337 V = -0.463 V
The standard Gibbs free energy (ΔG°) is a way to measure the spontaneity of a reaction. We can calculate it using the following expression.
ΔG° = − n × F × E°cell =
ΔG° = − 2 mol × (96,485 J/V.mol) × (-0.463 V) × (1 kJ/1000 J) = 89.3 kJ/mol
where,
n are the moles of electrons involvedF is Faraday's constantSince ΔG° > 0, the reaction is not spontaneous.
The standard Gibbs free energy for the reaction
Pb²⁺(aq) + Cu(s) → Pb(s) + Cu²⁺(aq) is 89.3 kJ/mol.
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A gas occupies 3.5L at 2.5 kPa pressure. What is the volume at 100 mmHg at the same temperature? Be sure to
show the setup and the final answer and unit.
Show Your Work
Answer:
V₂ = 0.656 L
Explanation:
Given data:
Initial volume = 3.5 L
Initial pressure = 2.5 KPa
Final volume = ?
Final pressure = 100 mmHg (100/7.501=13.33 KPa)
Solution:
The given problem will be solved through the Boyle's law,
"The volume of given amount of gas is inversely proportional to its pressure by keeping the temperature and number of moles constant"
Mathematical expression:
P₁V₁ = P₂V₂
P₁ = Initial pressure
V₁ = initial volume
P₂ = final pressure
V₂ = final volume
Now we will put the values in formula,
P₁V₁ = P₂V₂
2.5 KPa × 3.5 L = 13.33 KPa × V₂
V₂ = 8.75 KPa. L/13.33 KPa
V₂ = 0.656 L
Based on the structural formulas above, which of the following identifies the compound that is more soluble in water and best helps to explain why?
(A) Ethane, because the electron clouds of its molecules are more polarizable than those of propanol.
(B) Ethane, because its molecules can fit into the spaces between water molecules more easily than those of propanol can.
(C) Propanol, because its molecules have a greater mass than the molecules of ethane have.
(D) Propanol, because its molecules can form hydrogen bonds with water molecules but those of ethane cannot.
Answer:
D. Ethane molecules have no hydrogen bonds and need less energy to separate.
Explanation:
Edge2020
Have a great day y'all :)
Based on the structural formulas, the compound that is more soluble in water and best helps to explain is Propanol, because its molecules can form hydrogen bonds with water molecules but those of ethane cannot. Therefore, option D is correct.
What do you mean by the chemical formula ?A chemical formula is a notation used by chemists to represent the number and kind of atoms present in a molecule. A written chemical formula is a straightforward illustration of an actual, three-dimensional molecule.
There are three main types of chemical formulas: empirical, molecular and structural.
Chemical bonds connecting the atoms of a molecule are located in structural formulae. A structural formula is made up of symbols for the atoms joined by brief lines that stand in for chemical bonds.
Propanol is the substance that is more soluble in water and better aids in explanation based on structural formulae, as opposed to ethane, whose molecules are unable to establish hydrogen bonds with water molecules.
Thus, option D is correct.
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Which of the following items depends on electrical
conductors for operation?
A. cell phones
B. household wires
C. televisions
D. toaster
Answer:
C : Television
Explanation:
We should click on button from where the wire gets connected to the tv and operate. TV needs electric conductor for the flow of current .
Enter the correct 4 digit code (no spaces) *
Answer:6969?
Explanation:
Name the noble gases. What are the common properties between them?
composition variable
a, element
b. mixture
c. substance
d. compound
e. matter
Answer:
c. Substance
Explanation:
A composition variable is an intensive property that indicates the relative amount of a particular species or substance in a phase.
Answer:
is b the anwer is b
Explanation:
because mixture is a composition variable
PLEASE HELP!! Due in a few minutes!!! BRAINLEST TO WHO ANSWERS FIRST!!!
2.2.4 Study: Reaction Rates
POSSIBLE POINTS: 1.
Collisions between reactant molecules lead to a reaction when the molecules have the correct orientation and enough kinetic energy
True
False
Answer:
True
Explanation:
Hope this isnt too late
Explain difference in melting points for the elements Na and Mg
Answer:
magnesium has a greater charge, there will be greater attraction between delocalised electrons and the positively charged ion.
Explanation:
I did this once and got it right I hope you get it right too
A gas with a pressure of 820.4 mmHg occupies a
volume of 900.0 mL at a temperature of 25.0°C. If
the pressure does not change, what is the new
volume of the gas at 132.0°C?
A) 1220 L
B) 4750 L
C) 4750 mL
D) 1220 mL
Answer:
V₂ = 1223.2 mL
Explanation:
Given data:
Pressure of gas = 820.4 mmHg
Initial volume of gas = 900.0 mL
Initial temperature = 25.0°C (25+273=298K)
Final temperature = 132.0°C (132.0 +273 = 405 K)
Final volume = ?
Solution:
Solution:
The given problem will be solve through the Charles Law.
According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.
Mathematical expression:
V₁/T₁ = V₂/T₂
V₁ = Initial volume
T₁ = Initial temperature
V₂ = Final volume
T₂ = Final temperature
Now we will put the values in formula.
V₁/T₁ = V₂/T₂
V₂ = V₁T₂/T₁
V₂ = 900.0 mL × 405 K / 298 k
V₂ = 364500 mL.K / 298 K
V₂ = 1223.2 mL
Photosenthisis is a process in which plants prepare foodusing carbon dioxide chloriphil and water in the presence of sunlight during pphotosenthisus enerrgy is transformed into energy
Answer:
During photosynthesis SOLAR enerrgy is transformed into CHEMICAL energy.
Explanation:
In nutrition, green plants manufactures their own food which they use for both energy and growth. This is called an autotrophic mode of nutrition.
Therefore, photosynthesis is an autotrophic nutrition in which plant can build sugar by taking carbon dioxide from air and water from the soil. For the synthesis of sugar like glucose, carbon dioxide provides carbon
and oxygen whereas water molecules provide hydrogen. The plant builds sugar molecules from these simple compounds. Enzymes needed for this purpose are present in the cells and energy is trapped by chlorophyll from sunlight. This process is summarised in the equation below:
Sunlight (solar)
6CO2 + 6H2O--------------------> C6H12O6 + 6O2
From the equation, Carbon dioxide, water and sunlight (SOLAR energy) is the raw materials needed to produce Glucose and oxygen (CHEMICAL energy) as by products.
In chemical reactions, how does the valence configuration of bromine tend to change?
Answer: Near the Protons. The electron structure of bromine is illustrated above. In chemical reactions, how does the valence configuration of Bromine tend to change? ... It loses one electron.
Explanation:
btw i found that on google lol
Consider the equation:
4AI+3O2 → 2AI2O3
Is this equation balanced? Why or why not?
Answer:
Yes, it is balanced because the number of atoms of each element was same for both reactant side and product side.
Explanation:
Atoms of elements combine with one another to form compounds in a process called chemical reactions. In this case, atoms of Aluminum (Al) combines with atoms of Oxygen (O) to form Aluminum oxide (Al2O3).
However, for a chemical reaction to obey the law of conservation of mass, it needs to be BALANCED. Being balanced, for a chemical reaction, means the number of atoms of each element on the reactant side must equal the ones on the product side. To do this, coefficients are used at the back of each elements.
The original equation looks like:
AI + O2 → AI2O3
To make this balanced, coefficients 4 and 3 were used at the back of Al and O2 respectively while coefficient 2 was used behind Al2O3 as follows:
4AI+3O2 → 2AI2O3
Hence, the equation provided in this question is already balanced because the number of atoms of each element was same for both reactant side and product side.
A balloon with a volume of 5.0 L is filled with a gas at 760 torr. If the pressure is reduced to 380 torr without a change in temperature, what will be the volume of the balloon?
Answer:
10 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{5 \times 760}{380} = \frac{3800}{380} = \frac{380}{38} \\ [/tex]
We have the final answer as
10 LHope this helps you
By applying Boyle's law, the final volume of this balloon is equal to 10,000 mL.
Given the following data:
Initial volume = 5.0 L.
Final pressure = 380 torr.
Initial pressure = 760 torr.
How to calculate the final volume?In order to determine the final volume of this balloon, we would apply Boyle's law.
Mathematically, Boyle's law is given by this formula:
PV = k
P₁V₁ = P₂V₂
Where:
P represents the pressure.V represents the volume.Making V₂ the subject of formula, we have:
V₂ = (P₁V₁)/P₂
Substituting the given parameters into the formula, we have;
V₂ = (760 × 5.0)/380
V₂ = 3800/380
V₂ = 10 L
In milliliters, we have:
1 L = 1000 mL
10 L = X mL
X = 1000 × 10
V₂ = 10,000 mL.
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Why do your body and your cells need water?
Explanation:
Water the essential constituent of protoplasm of living cells because it is directly involved in countless biochemical reactions like photosynthesis and respiration without it cells couldn't move waste and by-products taking nutrients perform intracellular Transportation functioning and signaling
A cat that weighs 55 N sits on the top of a cat tree. It is 2 m above a 110N dog. How does the mass of the animals relate to the force of gravity on them?
*sorry I can't give a full explanation.*
g = 9.8 m/s²
w = m*g
Weight of cat: 55 N = m*9.8
m = 5.61 kg
Weight of dog: 110 N = m*9.8
m = 11.22 kg
There is gravitational potential energy (GPE) acting on the cat since it's at the very top.
GPE of cat = m*g*h = 5.61*9.8*2 = 109.96 J
GPE of dog = m*g*h = 11.22*9.8*0 = 0 J (it's 0 m height because it's on the floor instead of in the tree)
But, if the dog was also 2 m up in the tree, its GPE would be 219.91 J.
As you can see, it's GRAVITATIONAL potential energy is bigger than the cat because it weighs more. Generally, if you were just trying to find the force which is w = m*g (since weight is a force), you would see that the bigger the mass, the bigger the force, and gravity stays the same.
Hope this helped
describe what the periods and groups on the periodic table are, how they are different, and what they tell us about an atoms structure.
Explanation:
Periods and groups describes the arrangement of elements on the periodic table using the atomic number of each of the given elements.
Elements having the same number of electrons in the outermost shell of their atoms are placed over one another in vertical columns. Each of the resulting vertical column is the group or family. The resulting horizontal row is known as the periods.Elements in the same period have the same number of energy levels or electronic shell.
The period of an element is an indicator of the energy levels in an atom. The groups precisely tells us the number of valence electrons in the atom.
What is used to determine the number of a type of atom in a compound based on the chemical name?
- The periodic table
- chemical symbols
- prefixes
- the IUPAC
Answer:
Prefixes
Explanation:
The number of atoms of certain elements determines the prefix used.
02.04 Slide #2 Fill in the blanks based on the videos T Speed of reaction. When the of the reactants are moving too in a chemical reaction, there are fewer between particles. This means there are fewer for particles to correctly. Here you see two particles moving slowly. Though these particles seem ready to react, their slow speeds do not allow them to have the to react in this particular case. Instead, these particles just bounce apart. Particle alignment. If the particles of the reactants in a are not aligned Just right during a collision, they will away from one another. Here you see two particles moving toward each other. However, they are not facing each other in the right way to react. These particles just bounce away from each other.
Answer:
kylee is the best
Explanation:
What geological process changes pieces of rocks, minerals, and other material into sedimentary rock?
Heat rising in a hot-air balloon is an example of __________. (4 points)
a
conduction
b
convection
c
radiation
d
solar
Answer:
convection
Explanation:
hope it's useful to you
Which of the following are true about a block of ice at -10°C as you continue to apply heat.
Its temperature will not rise above -10°C until it melts.
Its temperature will rise until reaching 0°C.
Its temperature will rise continuously until it completely melts.
Its temperature will remain at 0°C until all the ice melts.
Revolution- is the orbiting of an object around another object... so what can i put as my example of revolution?
Answer:
The earth circling the sun
SCIENCEEEE!!!!! HELPPPP!!!!
pretty sure it's both are physical changes.
Answer:
I would say Both are only physical changes.
Explanation:
Melting wax isn't creating a new substance, or changing the atomic structure. The wax is only changes from a solid to a liquid state. Sanding a piece if wood is usually done with sandpaper, which can physically be done with your hands. Hope this helped :)
Ionic compound to name ai2o3
Explanation:
aluminium oxide had the chemical formula Al2O3
The name of ionic compound Al₂O₃ is aluminium oxide.
The naming of ionic compounds involves using the names of the constituent ions to form the compound's name. The name of the cation (positively charged ion) comes first, followed by the name of the anion (negatively charged ion).
Here are the general steps to name an ionic compound:
Name the cation: Use the name of the metal or polyatomic ion as it appears in the periodic table or ion list. If the metal has multiple oxidation states, use Roman numerals in parentheses to indicate the charge.Name the anion: For monatomic anions (single atoms), use the root name of the nonmetal element and add the suffix "-ide." For polyatomic anions (multiple atoms bonded together), use their specific names as listed in tables or formulas.Combine the names: Put the cation name first, followed by the anion name.Learn more about Naming of ionic compounds, here:
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Boiling Point is the __________. *
Answer:
it is a point at which a liquid Start's to evaporate
Explanation:
the point at which a liquid turns to gass
.A person is unable to see distinctly the objects placed at large distances but is able to read a book comfortably. Name the defect of vision he is suffering from
Answer:
The defect of vision suffered by the person is Myopia
Explanation:
The person can't see farther objects but is able to read a book which is placed closely to the eyes, using these observations the person is suffering from MYOPIA(nearsightedness) in which observer see close objects clearly but farther objects appear blurred.
The light entering the eye isn't correctly bent, the eyeball becomes big , or the eye lens become too converging, which converges the light ray in front of the cornea
This defect can be cured by using concave lenses.