Answer:
A
Explanation:
Answer:a
Explanation:
A photon with a wavelength of 397nm is emitted from an electron in energy level 7 of a Hydrogen atom. What is the new energy level of the electron?
Answer:
New energy level is n = 2
Explanation:
ΔE = energy released by e⁻ transition n = 7 to n(final) = - h·c/λ
h = Planck's Constant = 6.63 x 10⁻³⁴ j·s
c = speed of light in vacuum = 3 x 10⁸ m/s
λ = wavelength = 397 nm = 3.97 x 10⁻⁷ m
ΔE = - (6.63 x 10⁻³⁴j·s )(3 x 10⁸ m/s)/(3.97 x 10⁻⁷ m) = - 5.01 x 10⁻¹⁹ joule
Note: this is the transitional energy 'released' by the electron moving from n = 7 energy level to n(final) energy level. As released energy, the system should be represented by an exothermic process hence, the negative value for ΔE = - h·c/λ. The equivalent amount of energy is an absorption of electromagnetic energy (EMR) to promote the electron from n(final) to n = 7 and this would be endothermic as noted with a +h·c/λ .
The Bohr Model of the electron behavior postulates electron transitions by the release of a 'discrete' amount of EMR as emission spectra defined by the expression ...
ΔE = E(final) - E(initial) => E(final) = ΔE + E(initial)
E(n) = positional (potential) energy content of electron while in energy level n and is defined by the expression E(n) = -R(H)/n²
R(H) = Rydberg Constant = 2.18 x 10⁻¹⁸ joules
n = positional energy level (in this case) = 7
E₇ = -2.18 x 10⁻¹⁸ j / (7)² = -4.45 x 10⁻²⁰ j (potential energy of n = 7 electron)
E(final) = ΔE + E₇ = (-5.01 x 10⁻¹⁹ j) + (-4.45 x 10⁻²⁰ j) = -4.455 x 10⁻¹⁹ j
E(final) = -R(H)/n²
=> n = SqrRt[R(H)/E(final)] = SqrRt[(-2.18 x 10⁻¹⁸ j)/(-4.455 x 10⁻¹⁹)] ≅ 2
New energy level is n = 2
When a stalactite is formed by water leaving mineral deposits from the ceiling of a cave, this is caused by_____
A:Erosion
B: deposition
Answer:
it is b
Explanation: As the carbon dioxide is released, calcite is precipitated or redeposited on cave walls, ceilings and floors. As the redeposited minerals build up after countless water drops, a stalactite is formed.
What is the name of this molecule?
Answer: The answer is either A or C. I'm leaning more towards A.
Answer:
I think its C :)
help with this........
Which of the following is the term for the heaviness on something's surface that exerts a force over an area? a. force b. pressure c. sediment d. depositionn
The term for the heaviness on something's surface that exerts a force over an area is pressure. The correct option is b. pressure
Definition of PressureFrom the question, we are to determine the term for the heaviness on something's surface that exerts a force over an area.
Here, we are talking about pressure.
Pressure is defined as the physical force exerted on an object. Mathematically, it is defined as the perpendicular force per unit area.
That is,
[tex]P = \frac{Force}{Area}[/tex]
Where P is the pressure
The units of pressure are Newtons per square meter (N/m²), Pascals etc.
Hence, the term for the heaviness on something's surface that exerts a force over an area is pressure. The correct option is b. pressure
Learn more on Pressure here: https://brainly.com/question/16789304
Based on information from the periodic table, what does this image represent?
A. A neutral fluorine atom
B. A negatively charged fluoride atom
C. A positively charged fluoride ion
D. A neutral neon atom
Based on the information given, the image represents a negatively charged fluoride atom (Option B)
Composition of atomAn atom is composed of a centrally placed nucleus (containing protons and neutrons) and a cloud of electrons revolving round it.
How to determine the chargeFrom the question given above, the following data were obtained:
Proton = 9Neutron = 10Electron = 10Charge =?Charge = Proton – Electron
Charge = 9 – 10
Charge = –1
Note
Element with proton number of 9 is fluorine
Thus, we can conclude that the image represents a negatively charged fluoride ion (Option B)
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Answer:
B
Explanation:
Un Hidrocarburo de peso molecuar 42g/mol contiene un 85,7 de carbono, ¿cual es la formula empirica y molecular?
Answer:
1 respuesta. fórmula empírica = CH2
Explanation:
Translatation: 1 Answer. empirical formula = CH2
where does energy come from? newsela
Answer:
All of our energy comes from the sun.
Explanation:
The sun sends out huge amounts of energy through its rays every day. Without the sun, life on earth would not exist, since our planet would be totally frozen.
Calculate the equilibrium constant of the reaction below if the pressures are 1.0atm, 2.0 atm, and 1.0 atm respectively. PCl3 + Cl2 <--> PCl5
Answer:
K = 0.5
Explanation:
Based on the reaction:
PCl₃ + Cl₂ ⇄ PCl₅
The equilibrium constant, K, is defined as:
K = P PCl₅ / P PCl₃ * P Cl₂
Where P represent the pressure at the equilibrium for each one of the gases involved in the equilibrium.
As:
P PCl₅ = 1.0atm
P PCl₃ = 1.0atm
P Cl₂ = 2.0atm
K = 1.0atm / 1.0atm * 2.0atm
K = 0.5The track along which electricity flows is called a:
fuse
circuit
switch
The heat of vaporization of a liquid is 84.0 J/g. How many joules of heat would it take to completely vaporize 172 g of this liquid at its boiling point?
Answer:
14,448 J of heat would it take to completely vaporize 172 g of this liquid at its boiling point.
Explanation:
The heat Q that is necessary to provide for a mass m of a certain substance to change phase is equal to Q = m*L, where L is called the latent heat of the substance and depends on the type of phase change.
During the evaporation process, a substance goes from a liquid to a gaseous state and needs to absorb a certain amount of heat from its immediate surroundings, which results in its cooling. The heat absorbed is called the heat of vaporization.
So, it is called "heat of vaporization", the energy required to change 1 gram of substance from a liquid state to a gaseous state at the boiling point.
In this case, being:
Q=?m= 172 gL= 84 [tex]\frac{J}{g}[/tex]and replacing in the expression Q = m*L you get:
Q=172 g*84 [tex]\frac{J}{g}[/tex]
Q=14,448 J
14,448 J of heat would it take to completely vaporize 172 g of this liquid at its boiling point.
You are performing a reaction involving the collection of a gas at SATP. If 5.00 g of magnesium is added to 100.0 cm3 of 0.100 mol dm−3 HCl, determine the volume of hydrogen gas that will be collected at SATP.
Answer: The volume of hydrogen produced is 0.122 L
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of solute}={\text{Molarity}}\times {\text{Volume in L}}[/tex]
[tex]\text{Moles of} Mg=\frac{5.00g}{24g/mol}=0.208moles[/tex]
[tex]\text{Moles of} HCl=[/tex][tex]0.100moldm^{-3}\times 0.1dm^3=0.01mol[/tex]
The balanced chemical equation is:
[tex]Mg+2HCl\rightarrow MgCl_2+H_2[/tex]
According to stoichiometry :
2 moles of require = 1 mole of
Thus 0.01 moles of [tex]HCl[/tex] will require=[tex]\frac{1}{2}\times 0.01=0.005moles[/tex] of [tex]Mg[/tex]
Thus is the limiting reagent as it limits the formation of product and is the excess reagent.
As 2 moles of give = 1 mole of
Thus 0.01 moles of [tex]HCl[/tex] give =[tex]\frac{1}{2}\times 0.01=0.005moles[/tex] of [tex]H_2[/tex]
According to ideal gas equation:
[tex]PV=nRT[/tex]
P = pressure of gas = 1.0 atm (SATP)
V = Volume of gas = ?
n = number of moles = 0.005
R = gas constant =[tex]0.0821Latm/Kmol[/tex]
T =temperature =[tex]25^0C=(25+273)K=298K[/tex] (SATP)
[tex]V=\frac{nRT}{P}[/tex]
[tex]V=\frac{0.005mol\times 0.0820 L atm/K mol\times 298K}{1.0atm}=0.122L[/tex]
Thus volume of hydrogen produced is 0.122 L
Acids react with
O water to produce bases and salts
salts to produce bases and water
O neither bases, salts nor water
O bases to produce salts and water
Create the Equation: How many grams of Aluminum Chloride would be made in a reaction between 50.0 g of Aluminum and 125g of Magnesium Chloride?
Answer:
0g
Explanation:
Magnesium is more reactive than aluminium so no reaction occurs
A gas system has an initial number of moles of 0.693 moles with the volume unknown. When the number of moles changes to 0.928 moles volume is found to be 7.98 L. What was the initial volume in mL?
Answer:
The initial volume in mL is 5959.2 mL
Explanation:
As the number of moles of a gas increases, the volume also increases. Hence, number of moles and volumes are directly proportional i.e
n ∝ V
Where n is the number of moles and V is the volume
Then, n = cV
c is the proportionality constant
∴n/V = c
Hence n₁/V₁ = n₂/V₂
Where n₁ is the initial number of moles
V₁ is the initial volume
n₂ is the final number of moles
and V₂ is the final volume.
From the question,
n₁ = 0.693 moles
V₁ = ?
n₂ = 0.928 moles
V₂ = 7.98 L
Putting the values into the equation
n₁/V₁ = n₂/V₂
0.693 / V₁ = 0.928 / 7.98
Cross multiply
∴ 0.928V₁ = 0.693 × 7.98
0.928V₁ = 5.53014
V₁ = 5.53014/0.928
V₁ = 5.9592 L
To convert to mL, multiply by 1000
∴ V₁ = 5.9592 × 1000 mL
V₁ = 5959.2 mL
Hence, the initial volume in mL is 5959.2 mL
Which solute, an electrolyte or a nonelectrolyte, has the greater effect on the boiling point when a given amount of each
solute is dissolved in the same mass of water?
O The nonelectrolyte does because it disperses into molecules.
O The electrolyte does because it disperses into molecules.
O The nonelectrolyte does because it dissociates into ions.
O The electrolyte does because it dissociates into ions.
The solute wether electrolyte or a nonelectrolyte, has the greater effect on the boiling point when a given amount of each solute is dissolved in the same mass of water The nonelectrolyte does because it dissociates into ions.
What is a solute?Solute refers to substances or liquid which can readily dissolve in a solvent. It's concentration is lower to that of solvent.
Therefore, The solute wether electrolyte or a nonelectrolyte, has the greater effect on the boiling point when a given amount of each solute is dissolved in the same mass of water The nonelectrolyte does because it dissociates into ions
Learn more about solute below.
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Answer:
D: The electrolyte does because it dissociates into ions.
Explanation:
which of these phenomena cause uneven heating of the earth
Land and water have different heat capacities
Land and water have the same rate of heat absorption
The angle of incoming sunlight varies at different places
Air travels from areas of low pressure to areas of high pressure
Winds blow in the same direction across Earth's Surface
Answer:
The angle of incoming sunlight varies at different places
Answer: This answer is multiple choices.
1. Land and water have different heat capacities.
And
3. The angle of incoming sunlight varies at different places.
Explanation: I kept seeing other people only putting in one answer, so I used this answer from someone else. Credit to them!
What type of product is formed when acids are added to some ionic compounds
Answer:
salt
Explanation:
When acid and base solutions react, they produce water and a neutral ionic compound called a salt.
3) Pick the correct definition for : A signal represented by a continuous wave *-1 analog signal-2 digitized siganal-3-encode-4-transmit-5-wave pulse.
plzzzz help brainliest and 50 points
Answer:
it is analog signal, your welcome
Analog Signal is the correct answer
Hope it helps you
I need answers to the lab report.
Answer:
Title.
Abstract.
Introduction.
Method.
Results and analysis.
Discussion.
Conclusion.
References.
The standard molar enthalpy of vaporization for water is 40.79kJ/mol. What mass of steam is required to release 500 kJ of energy upon condensation?
Answer:
220.9g of water are required
Explanation:
The molar enthalpy of vaporization is defined as the heat released when 1 mole of water changes from liquid to gas.
For water, 1 mole releases 40.79kJ. To release 500kJ are necessaries:
500kJ * (1mol / 40.79kJ) = 12.26 moles are necessaries
To convert moles to grams we must use the molar mass (H2O = 18.02g/mol):
12.26 moles * (18.02g / 1 mol) =
220.9g of water are requiredWhich two properties define the critical point of matter in a phase diagram? A. mass and volume B. pressure and volume C. pressure and temperature D. density and temperature E. density and pressure
Answer:
C. pressure and temperature
Explanation:
For each substance, the conditions defining the critical point are the critical temperature, the critical pressure, and the critical density.
Hope this helped!!!
Pressure and temperature are the properties defining the critical point of matter in a phase diagram. The correct option is C.
What is a phase diagram?A phase diagram is a visualization of a material's physical states under various situations of pressure and temperature.
Pressure is on the y-axis of a typical phase diagram, and temperature is on the x-axis. A phase transition when we cross the lines or curves on the phase diagram.
The pressure and temperature point on a phase diagram where a material's liquid and gaseous phases merge into a single phase.
The merged single phase is known as a supercritical fluid above the critical point temperature.
Phase diagrams are graphical representations of the connections between the various phases that appear in a system under equilibrium conditions.
Thus, the correct option is C.
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Complete each nuclear reaction equation.
Superscript 14 subscript 7 upper N plus superscript 4 subscript 2 upper H e right arrow superscript question mark subscript 8 upper O plus superscript 1 subscript question upper H.
Nitrogen transmutes to form an isotope of oxygen. The superscript for oxygen is?
The subscript for hydrogen is?
Superscript 59 subscript question mark upper C o plus superscript 1 subscript 0 n right arrow superscript 60 subscript 27 upper C o.
Cobalt-59 accepts a neutron to form a new isotope. The subscript for cobalt is?
Nitrogen transmutes to form an isotope of oxygen. The superscript for oxygen is 17
The subscript for hydrogen is 1
Cobalt-59 accepts a neutron to form a new isotope. The subscript for cobalt is 27
Answer:
Oxygen = 17
Hydrogen = 1
Cobalt = 27
Explanation:
Please help me with this homework
What is the difference between the reaction of CH3COOH with H20 and with OH?
Answer:
Explanation: CH3COOH(aq) + H2O(l) ↔ CH3COO-(aq) + H3O+(aq) acid base ... sulfuric acid can react with either OH- or. H.
What is the equilibrium constant for the chemical equation:
1. N2 (g) + 3H2 (g) ↔ 2NH3 (g)
At equilibrium, the concentration of N2 is 2.5 x 10-4 M, the concentration of H2 is 6.4 x 10-3 M, and the concentration of NH3 is 5.3 x 10-2 M.
Write out the equilibrium constant, Keq, and show you work.
2. Mg3P2 (s) ↔ 3Mg+2 (aq) + 2P-3 (aq)
At equilibrium, the concentration of Mg3P2 is 5.5 x 10-6 M, the concentration of magnesium ions is 7.2 x 10-5 M, and the concentration of phosphide ions is 9.8 x 10-8 M.
Write out the equilibrium constant, Keq, and show you work.
Answer:
beaner
Explanation:
Answer:
x= 1 /5 y+ 4 /5
Explanation:
Let's solve for x.
10x−2y=8
Step 1: Add 2y to both sides.
10x−2y+2y=8+2y
10x=2y+8
Step 2: Divide both sides by 10.
10x /10 = 2y+8 /10 x= 1 /5 y+ 4 /5
Can someone answer this pls
Answer:12
Explanation:
which is BEST used to describe a chemical reaction that also produces a change in heat?
a. exothermic reaction
b. chemical reaction
c. thermochemical reaction
d. nuclear reaction
will give brainliest
Answer:
I think it's thermochemical reaction and sorry if it's wrong
the formula equation of Sodium carbonate + hydrochloric acid
→ sodium chloride + carbon dioxide + water
Answer:
the reaction is: Na2CO3 + 2HCl ===》 2NaCl + H2O + CO2(g)
What does a negative AHf for a molecule mean?
A. Energy was added when the molecule changed phases.
B. Energy was added when the molecule was formed from its
elements.
C. Energy was released when the molecule was formed from its
elements.
O D. Energy was released when the molecule went through a phase
change.
SUBMIT
Option D I got it right
ANSWER: C (ENERGY WAS RELEASED WHEN THE MOLECULE WAS FORMED FROM ITS ELEMENTS.)
HOPE THE OTHER PERSON IS WRONG!