The three major categories of energy for electricity generation are fossil fuels (coal, natural gas, and petroleum), nuclear energy, and renewable energy sources.
If you hit the surface of Iron with a photon of energy and find that the ejected electron has a wavelength of .75 nm, what is the wavelength of the incoming photon in nanometers?
Answer:
The wavelength of the incoming photon is 172.8 nm
Explanation:
The wavelength of the incoming photon can be calculated with the photoelectric equation:
[tex] KE = h\frac{c}{\lambda_{p}} - \phi [/tex] (1)
Where:
KE: is the kinetic energy of the electron
h: is Planck's constant = 6.62x10⁻³⁴ J.s
c: is the speed of light = 3.00x10⁸ m/s
[tex]\lambda_{p}[/tex]: is the wavelength of the photon =?
Φ: is the work function of the surface (Iron) = 4.5 eV
The kinetic energy of the electron is given by:
[tex] KE = \frac{p^{2}}{2m} = \frac{(\frac{h}{\lambda_{e}})^{2}}{2m} [/tex] (2)
Where:
p: is the linear momentum = h/λ
m: is the electron's mass = 9.1x10⁻³¹ kg
[tex]\lambda_{e}[/tex]: is the wavelength of the electron = 0.75 nm = 0.75x10⁻⁹ m
Hence, the wavelength of the photon is:
[tex] \frac{(\frac{h}{\lambda_{e}})^{2}}{2m} = h\frac{c}{\lambda_{p}} - \phi [/tex]
[tex]\lambda_{p} = \frac{hc}{\frac{h^{2}}{2m\lambda_{e}^{2}} + \phi} = \frac{6.62 \cdot 10^{-34} J.s*3.00\cdot 10^{8} m/s}{\frac{(6.62 \cdot 10^{-34} J.s)^{2}}{2*9.1 \cdot 10^{-31} kg*(0.75 \cdot 10^{-9} m)^{2}} + 4.5 eV*\frac{1.602 \cdot 10^{-19} J}{1 eV}} = 1.728 \cdot 10^{-7} m = 172.8 nm[/tex]
Therefore, the wavelength of the incoming photon is 172.8 nm.
I hope it helps you!
Question 8 of 10
Which of the following is made of matter?
A. Light
B. Energy
C. The sun
D. Heat
Answer: i Choose the sun
because it has mass
Explanation: matter is anything that has mass and occupies space / Volume
and the sun has mass though it is not a solid one, and is made up of matter
HOPE THIS HELPSS!!!!
Analyse the temperature versus time graph of water, given below.
Which part of graph represent only liquid state and gaseous state and why?
Answer:
Phase C - Liquid State
Phase E - Gaseous State
Explanation:
Usually, in phases of water, we have the following;
When temperature is less than zero, it is said to be in its solid phase as ice.
When temperature is between 0 to 100, we can say it is in the liquid phase as water.
When temperature is above 100°C, It is said to be in the gaseous phase as vapour.
From the diagram;
Phase C is the only liquid state because it falls between temperature of 0°C and 100°
Also, only phase E is in the gaseous phase because the temperature is above 100°C.
What is the action of a catalyst
Answer: A catalyst is a substance that speeds up the rate of a chemical reaction without being used up and remains chemically unchanged itself .
Explanation: For a reaction to take place the particles must collide with enough energy for bonds to break and reaction to occur .
BUT when a catalyst is present the reactants are able to react in a way that requires less energy ,leading to more successful collision so the reaction speeds up without the chemical composition of the catalyst being affected
NOTE: the catalyst must be chosen to suit the particular reaction
HOPE THIS HELPS IF YOU NEED MORE EXAMPLES FEEL FREE TO COMMENT IN THE COMMENT SECTION
hii pls help me to write the ionic equation
Answer:
net ionic equation
[tex]\boxed{ SO_4{}^{2-} {}_{(aq.)} + Ba^{2+} {}_{(aq.)} \rightarrow BaSO_4 {}_{(s)}} [/tex]
Chromium forms a complex with diphenylcarbazide whose molar absorptivity is 4.17*10^4 at 540nm. Calculate the absorbance of a 7.68*10^-6 M solution of the complex at 540nm when measured in a 1.00cm cell and the transmittance of the solution.
Answer:
0.32 liters/mole cm.
Explanation:
According to Beer Lambert's law;
A= εcl
ε = molar absorptivity
c= concentration
l= path length
A= 4.17*10^4 × 7.68*10^-6 × 1
A= 0.32 liters/mole cm.
what is Ka for hno2(aq) = h+(aq) + no2-(aq)?
The ionization constant of an acid is denoted by the symbol Kₐ. The smaller the value of Kₐ for an acid, the weaker will be the acid. Thus the correct option is D.
What is acid dissociation constant?The acid dissociation constant denotes the measure of the extent to which an acid dissociates in the solution. The strength of an acid is represented by the value Kₐ. The less an acid dissociates, smaller will be the value of Kₐ, the stronger the acid, higher will be the value of Kₐ.
The dissociation of HNO₂ is given as:
HNO₂ (aq) ⇄ H⁺ (aq) + NO₂⁻ (aq)
The dissociation constant of HNO₂ is given as:
Kₐ = [H⁺][NO₂⁻] / HNO₂
The value of Kₐ is constant at a particular temperature. We can use this fact to find out the pH of a weak acid at a particular temperature.
Thus the correct option is D.
To know more about acid dissociation constant, visit;
https://brainly.com/question/14498573
#SPJ7
make a 450 gram solution with the mass by mass concentration of 7% how much salt and water do you need to mix
NaC2H3O2 product or reactant
Answer:
the reaction between vinegar and baking soda, the reactants are vinegar (acetic acid) and baking soda (sodium bicarbonate). The products are sodium acetate, water, and carbon dioxide gas.
What is the pH of a 1.0 x 10-3 M KOH solution?
A. 10
B. 4.0
C. 11
D. 3.0
Answer:
Option C. 11
Explanation:
We'll begin by calculating the concentration of the hydroxide ion [OH¯] in the solution. This can be obtained as follow:
In solution, KOH will dissociate as follow:
KOH (aq) <=> K⁺(aq) + OH¯(aq)
From the balanced equation above,
1 mole of KOH reacted to produce 1 mole of OH¯.
Therefore, 1×10¯³ M KOH will also react to produce 1×10¯³ M OH¯.
Thus, the concentration of hydroxide ion [OH¯] in the solution is 1×10¯³ M
Next, we shall determine the pOH of the solution. This can be obtained as follow:
Concentration of hydroxide ion [OH¯] = 1×10¯³ M
pOH =?
pOH = –Log [OH¯]
pOH = –Log 1×10¯³
pOH = 3
Finally, we shall determine the pH of the solution. This can be obtained as follow:
pOH = 3
pH =?
pH + pOH = 14
pH + 3 = 14
Collect like terms
pH = 14 – 3
pH = 11
Which diagram represents this molecule
Answer:
I think it is C
Explanation:
Hope this helps!! :)
If I'm wrong, then greatest apologies
PLEASE HELP QUICK!!! How many molecules are there in 4.00 L of
glucose, C6H1206? Please show your work!!
nguyên tử sắt có điện tích hạt nhân là 26+. trong nguyên tử, số hạt mang điện nhiều hơn số hạt không mang điện là 22. Hãy xác định số khối của nguyên tử sắt
Answer:
I don't know yr language
Is this population more likely to grows slowly or quickly in the next 10 years
nobody can say it is uncertain but in my opinion it will grow quickly in the next 10 years
Exprese la concentración de una solución de H3PO4 al 30 % en masa y con una densidad de 1.39 g/mL en: M, y N.
Respuesta:
4.26 M; 12.8 N
Explicación:
Primer paso: Calcular la concentración volumétrica (Cv)
Usaremos la siguiente expression.
Cv = Cg × ρ
Cv = 30 g%g × 1.39 g/mL = 41.7 g%mL
Segundo paso: Calcular la molaridad
La concentración volumetrica es 41.7 g%mL, es decir, hay 41.7 gramos de soluto cada 100 mL de solución. Usaremos la siguiente fórmula para molaridad.
M = masa de soluto / masa molar de soluto × litros de solución
M = 41.7 g / 97.99 g/mol × 0.1 L = 4.26 M
Tercer paso: Calcular la normalidad
Usaremos la siguiente fórmula.
N = M × Z
donde Z para un ácido es igual al número de protones.
N = M × Z
N = 4.26 mol/L × 3 eq/mol = 12.8 N
How does kinetic energy transform into potential energy?
TIMED HELP ASAP
19.11 g of MgSO₄ is placed into 100.0 mL of water. The water's temperature increases by 6.70°C. Calculate ∆H, in kJ/mol, for the dissolution of MgSO₄. (The specific heat of water is 4.184 J/g･°C and the density of the water is 1.00 g/mL). You can assume that the specific heat of the solution is the same as that of water.
Answer:
TIMED HELP ASAP
19.11 g of MgSO₄ is placed into 100.0 mL of water. The water's temperature increases by 6.70°C. Calculate ∆H, in kJ/mol, for the dissolution of MgSO₄. (The specific heat of water is 4.184 J/g･°C and the density of the water is 1.00 g/mL). You can assume that the specific heat of the solution is the same as that of water.
Answer:
-21.03 kJ/mol
Explanation:
∆H is enthalpy. Enthalpy is the total heat content of a system.
So we can establish that ∆H = q (heat)
The formula for heat (q)
q = cm∆T
c = specific heat capacity
m = mass of substance
∆T= change of temperature
Since we are calculating the enthalpy of the SOLUTION. We must account for both the mass of water and the mass of MgSO₄ in our q formula.
All you gotta do is plug and chug at this stage.
∆H = q = cm∆T = (4.184)(19.11+100.0)(6.70) = 3338.986808 Joules
We have now calculated the heat (aka enthalpy) of the solution.
BUT
Remember! The problem asked for enthalpy in kj....
Use this conversion factor.
1000 J = 1 kJ
3338.986808 Joules * 1kJ/1000 J = 3.338986808 kJ
We were asked to find ∆H for the dissolution of MgSO4 in units of kj/mol so we are not finished.
Take the grams of MgSO4 in the problem and convert it into moles using its molar mass.
MgSO4 molar mass = 120.3676 g
1 mol = 120.3676 g MgSO4 <---- Use this as a conversion factor
19.11 g MgSO4 * 1 mol MgSO4/120.3676 g = 0.15876365 mol MgSO4
Now that you've calculated the moles of MgSO4 in this solution. You can divide your heat by it.
q dissolution = 3.338.986808 kJ/ 0.15876365 mol = 21.03 kj/mol
Note that the problem tells us that the temperature of water increases.
This means that the water is experiencing an endothermic process (heat is being absorbed from MgSO4) . Mathematically, this would be indicated by a positive sign. ---> +q
We can assume MgSO4 is losing heat as it is placed into the water. It is experiencing an exothermic process (heat is being lost). Mathematically, this would be indicated by a negative sign. ----> -q
So if we're calculating the enthalpy for the dissolution of MgSO₄ ....the value we've arrived at must be negative.
Answer
∆H = 21.03 kj/mol :)))))
I hope that helped...I feel like my explanation was a bit convoluted.
If 30.0 grams of AlC3 is produced in the reaction, how many grams of HCI must have reacted?
Answer:
Al2O3 + 6HCl ==> 2AlCl3 + 3H2O ... balanced equation
moles Al2O3 present = 30.0 g x 1 mol/101.96 g = 0.294 moles
moles HCl present = 30 g HCl x 1 mol/36.5 g = 0.822 moles HCl
HCl is LIMITING as it takes 6 moles HCl for each 1 mol Al2O3 and here that is not enough. It will run out first.
Now, using the limiting reactant, we find the moles and mass of AlCl3 that can be formed.
0.822 moles HCl x 2 moles AlCl3/6 moles HCl = 0.274 moles AlCl3 formed
mass of AlCl3 = 0.274 moles AlCl3 x 133 g/mole = 36.4 g AlCl3 formed
Name each compound. Do not capitalize element names. An example can be seen
below.
Ex. SF6: sulfur hexfluoride
a. H2O:
b. PC15:
C. SiF4:
d. N20
Answer:
a. H2O: dihydrogen monoxide
b. PCl5: Phosphorus pentachloride
c. SiF4: Silicon tetrafluoride
d. N20: dinitrogen oxide
what is transition state
Answer:
transition state is a point in which electrons been removed from the atom
Answer:
The highest energy structure in the reaction coordinate.
Explanation:
How are the vapor pressure and boiling point of alkynes affected as the chain length increases?
Answer:
Answer to the following question is as follows;
Explanation:
Alkynes' vapour pressure and normal boiling points are altered when chain length grows, since vapour pressure rises while boiling point falls.
Vapour pressure always include pressure entered by vapour with its condensed phase, pressure include molecules force of attraction include vapour
PLZ HELP According to the atomic model Which particles are found In the same part of the atom
a. protons electrons neutrons
B.protons and neutrons
C.protons and electrons
D.electrons and neutrons
PLEASE HELP!!
Balance the equation below to answer the question. Suppose you mix 3.25 grams of nitrogen trihydride with 3.50 grams of oxygen gas. How many grams of nitrogen monoxide would you make?
A. 2.63 grams
B. 2.11 grams
C. 4.34 grams
D. 3.45 grams
E. 1.76 grams
A common oxidizing agent is..?
A. KI
C. KMnO4/H+
B. FeSO4
D. concentrated HCl
Answer:
C. KMnO4/H+
Explanation:
Oxidizing agent is a substance that has the ability to accept electrons from other substances.
what are the intermolecular forces of Sulfate ion
Answer:
oh it's easy
Explanation:
Take the hydrate
N
a
2
S
2
O
3
∙
5
H
2
O
. Are there ionic forces between the
N
a
+
and the
S
2
O
2
−
3
and ion-dipole forces between the cation/anions and the water?
What is the total pressure in millimeters of mercury,
exerted by the gas mixture
P= _______ units?
Answer:
87059.50558 pa
Explanation:
Dalton's law of partial pressure states that Ptotal=P1 +P2+ P3
417mmHg + 150mmHg +86mmHg =653 mmHg
convert it to Pa, your answer is 87059.50558Pa.
I hope I'm of help to you
is SrO a conductor of electricity
Answer:
No and Yes
Explanation:
it depends bc its an ionic compound, therefore can't conduct electricity when SOLID, BUT unless it DISSOLVES in water it can conduct
Indicar que elemento es de transición *
a) Calcio
b) Radio
c) Hierro
d) Carbono
e) Azufre
Sabiendo que las configuraciones electrónicas son correctas, determinar qué analogía es incorrecta *
a) 47Ag: [Kr] 5s2 4d9 I – B
b) 27Co: [Ar] 4s2 3d7 VIII – B
c) 41Nb: [Kr] 5s2 4d3 V – A
d) 50Sn: [Kr] 5s2 4d10 5p2 IV – A
e) N.A.
porfaaaaaaaaaaaaaaaaaaaa
Answer:
c hierro
no se la otra sorry
Which element has 2 valence electrons in the 2s sublevel?
Answer:
beryllium is the answer.
I hope this will help you
copper II carbonate in a crucible produced only 7g of copper II oxide. What was the percentage yield of copper II oxide
The question is incomplete, the complete question is;
.On heating 12.4 g of copper (II) carbonate in a crucible only 7.0g of copper (II) oxide was produced. What was the % yield of copper (II) oxide ? [Cu=64,C=12,O=16]
Answer:
87.5%
Explanation:
CuCO3 -------> CuO + CO2
Number of moles of CuCO3 = 12.4g/123.55 g/mol = 0.1 moles
Since the reaction is 1:1,
Mass of CuO produced = 0.1 moles × 80g/mol = 8 g
Hence,
% yield = actual yield/theoretical yield × 100
% yield = 7/8 × 100
% yield = 87.5%
