Answer:
a) 7.22 × 10⁻¹⁹ J; b) 275 nm; c) 1.38× 10¹² electrons; d) 9.1 × 10⁻¹⁹ J
Explanation:
a) Minimum energy to eject photon
E = hf = 6.626× 10⁻³⁴ J·s × 1.09 × 10¹⁵ s⁻¹ = 7.22 × 10⁻¹⁹ J
b) Wavelength required
fλ = c
[tex]\lambda = \dfrac{c}{f } = \dfrac{2.998 \times 10^{8}\text{ m/s}}{1.09 \times 10^{15}\text{/s}} = 2.75 \times 10^{-7} \text{ m} = \textbf{275 nm}[/tex]
c) Electrons required
[tex]\text{No. of electrons} = 1.00 \times 10^{-6}\text{ J} \times \dfrac{\text{1 electron}}{7.22 \times 10^{-19}\text{ J}} = 1.38 \times 10^{12}\text{ electrons}[/tex]
d) Kinetic energy of electrons
a) Energy of photon
[tex]E = hf = \dfrac{\text{hc}}{\lambda} = \dfrac{6.626 \times 10^{-34} \text{ J$\cdot$ s}\times 2.998 \times 10^{8} \text{ m/s}}{122 \times 10^{-9}\text{ m}}= 1.63 \times 10^{-18} \text{ J}[/tex]
b) Maximum kinetic energy
The equation for the photoelectric effect is
hf = φ + KE, where
φ = the work function of the metal — the minimum energy needed to eject an electron
KE = hf - φ = 1.63× 10⁻¹⁸ J - 7.22× 10⁻¹⁹ J = 9.1 × 10⁻¹⁹ J
a. The energy of molybdenum to eject electron has been [tex]\rm \bold{7.22\;\times\;10^{-19}}\;J[/tex].
b. The wavelength of the radiation has been 275 nm.
c. The number of electrons present in [tex]\rm 1\;\mu J[/tex] energy has been [tex]\rm \bold{1.38\;\times\;10^1^2}[/tex].
d. The kinetic energy of the emitted electrons as been [tex]\rm \bold{9.1\;\times\;10^-^1^9\;J}[/tex].
The metal emits the energy when it returns from the excited state to ground state.
a. The energy (E) to eject electron has been given by:
[tex]E=h\nu[/tex]
Where, the value of constant, [tex]h=6.626\;\times\;10^{-34}\;\rm J.s[/tex]
The value of frequency has been given, [tex]\nu=\rm 1.09\;\times\;10^{15}\;s^{-1}[/tex]
Substituting the values for energy:
[tex]E=6.626\;\times\;10^{-34}\;\times\;1.09\;\times\;10^{15} \rm J\\\textit E=7.22\;\times\;10^{-19}\;J[/tex]
The energy of molybdenum to eject electron has been [tex]\rm \bold{7.22\;\times\;10^{-19}}\;J[/tex].
b. The wavelength ([tex]\lambda[/tex]) of the radiation has been given by:
[tex]\lambda=\dfrac{c}{\nu}[/tex]
Where, the speed of light, [tex]c=3\;\times\;\rm m/s[/tex]
The frequency has been given as, [tex]\nu=1.09\;\times\;10^{15}\;\rm s^-^1[/tex].
Substituting the values for wavelength:
[tex]\lambda=\dfrac{3\;\times\;10^8}{1.09\;\times\;10^{15}}\;\rm m\\ \lambda=2.75\;\times\;10^-^7\;m\\\lambda=275\;nm[/tex]
The wavelength of the radiation has been 275 nm.
c. The electrons ([tex]e^-[/tex]) burst out can be given as:
[tex]e^-=\dfrac{E}{E'}[/tex]
Where, the energy of radiations, [tex]E=1\;\times\;10^{-6}\;\rm J[/tex]
The energy of each electron has been calculated as, [tex]E'=7.22\;\times\;10^{-19}\;\rm J[/tex]
Substituting the values for number of electrons:
[tex]e^-=\dfrac{1\;\times\;10^-^6}{7.22\;\times\;10^-^1^9} \\e^-=1.38\;\times\;10^1^2[/tex]
The number of electrons present in [tex]\rm 1\;\mu J[/tex] energy has been [tex]\rm \bold{1.38\;\times\;10^1^2}[/tex].
d. The maximum kinetic energy (K.E.) of the radiation has been given as:
[tex]K.E.=\dfrac{hc}{\lambda} -E^'[/tex]
Where, the value of constant, [tex]h=6.626\;\times\;10^{-34}\;\rm J.s[/tex]
The speed of light, [tex]c=3\;\times\;\rm m/s[/tex]
The wavelength of the radiation, [tex]\lambda=122\;\times\;10^-^9\;\rm m[/tex]
Energy of each electron, [tex]E'=7.22\;\times\;10^{-19}\;\rm J[/tex]
Substituting the values, for kinetic energy:
[tex]K.E.=\dfrac{6.626\;\times\;10^{-34}\;\times\;3.0\;\times\;10^8}{122\;\times\;10^-^9}\;-\;7.22\;\times\;10^-^1^9\;\rm J \\\textit {K.E.}=9.1\;\times\;10^{-19}\;J[/tex]
The kinetic energy of the emitted electrons as been [tex]\rm \bold{9.1\;\times\;10^-^1^9\;J}[/tex].
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Arrange the following rock particles which occur in soil in the decreasing order of their sizes:
Sand, Clay, Gravel, Silt.Immersive Reader
(1 Point)
Clay>Silt>Sand>Gravel
Silt>Clay>Sand>Gravel
Gravel >Sand>Silt>Clay
Answer:
Gravel >Sand>Silt>Clay
Explanation:
Sand, Clay, Gravel and Silt
Clay: all particles smaller than 0.002 mm
Silt: all particles within the size range of 0.002-0.05 mm;
Sand: all particles within the size range of (2.0 mm - 0.05 mm)
Gravel particles are larger than sand, ranging in size from 4.75 mm to 75 mm
Going through the options, the correct option is;
Gravel >Sand>Silt>Clay
What are the 3 critical components of an electromagnet and what purpose do they each serve?
Answer:
A source of electricity, a wire coil, and an iron core
Explanation:
An electromagnet has three critical components:
1. A source of electricity
This is often a battery.
It generates the electric current that produces the magnetic field.
2. A wire coil
The wire carries the electric current.
Stacking the wire into loops makes a stronger magnetic field.
The more loops in the coil, the stronger the field.
3. An iron core
An iron core greatly increases the strength of the magnetic field within it and at its ends.
Compounds formed from only non-metals consist of particles called
Answer:
Compounds formed from non-metals consist of molecules.
Explanation:
The atoms in a molecule are joined together by covalent bonds. These bonds form when atoms share pairs of electrons.
I hope I helped, please correct me if I'm wrong!
Considering the definition of covalent bond and molecules, compounds formed from only non-metals consist of particles called molecules.
But you have to know that the covalent bond is the chemical bond between atoms where electrons are shared, forming a molecule.
Covalent bonds are established between non-metallic elements, such as hydrogen H, oxygen O and chlorine Cl. These elements have many electrons in their outermost level (valence electrons) and have a tendency to gain electrons to acquire the stability of the electronic structure of noble gas.
The shared electron pair is common to the two atoms and holds them together.
In other words, a covalent bond is a type of chemical bond where two atoms of non-metallic elements join to form a molecule, where the atoms share pairs of electrons from their most superficial layer or valence layer to achieve stability in the molecule and thus complying with the octet rule.
In summary, compounds formed from only non-metals consist of particles called molecules.
Learn more:
https://brainly.com/question/12661797?referrer=searchResultshttps://brainly.com/question/4461443?referrer=searchResultshttps://brainly.com/question/11693996?referrer=searchResultsA 39 foot ladder is resting against a wall that is 36 feet high. What is
the distance between the base of the ladder and the bottom of the wall?
5 feet?
15 feet?
10 feet ?
Match each situation below to a letter on the illustration.
Ball
starts
here
Letter
Situation
Potential energy is the highest
Losing kinetic energy, gaining potential energy
Kinetic energy is highest
Losing potential energy, gaining kinetic energy
Answer:a
Explanation:
In the position A, the potential energy is maximum and the kinetic energy is minimum. At the point B, kinetic energy is highest. At the point C, the losing kinetic energy, gaining potential energy and at D, losing potential energy, gaining kinetic energy.
What is kinetic energy ?Kinetic energy of moving body is the energy generated by virtue of its position. Potential energy is generated by virtue of its position at a height from the surface. When a body starts moving from rest, its potential energy starts convert to kinetic energy.
As the height increases, potential energy increases. When an object moves down, its acceleration due to gravity increases and more energy to fall down make its kinetic energy higher.
Thus, the situations can be matched as follows;
A, the potential energy is maximum and the kinetic energy is minimum. B, kinetic energy is highest.
C, the losing kinetic energy, gaining potential energy and
D, losing potential energy, gaining kinetic energy.
Find more on kinetic energy :
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An electron is in a region outside the nucleus. An electron
a) Is larger than a proton and has no charge
b) Has less mass than a proton and has a negative charge
c) Is smaller than a proton and has no charge
d) Has a positive charge
Answer:
b
Explanation:
electrons lie in the orbits of the atom. they are negatively charged and they are very small in size. they have very less mass than proton. ele tron has 1/1840 mass of proton.
What state of matter has indefinite volume and is compressible?
a. Gas
B. Liquid
C. Both Liquid and Gas
D. Solid
0.5 g of salt is dissolved in 25 g of water. Calculate the percentage amount of salt in the solution.
Which statement describes a periodic trend of first ionization energy?
O A. It tends to decrease from left to right across a period.
B. It remains the same within a period.
O C. It tends to increase from top to bottom of a group.
D. It tends to decrease from top to bottom of a group.
Answer:
D
Explanation:
when ionic radius gets bigger, the valence electron is repelled further away from the nucleus due to higher number of principal quantum shells. it experiences less electrostatic forces of attraction with the nucleus and requires less energy to remove.
1. Identify whether each of the elements is a metal, non-metal, or metalloid:
Ruthenium: Neon:
Germanium: Neptunium:
Iodine: Strontium:
Cesium: Europium:
Answer:
neon - non metal
Explanation:
Answer:
Ruthenium → metalloidNeon → non-metalGermanium → metalloidNeptunium → metalIodine → non-metalStrontium → metalCaesium → metalEuropium → metalWhat is the mass of two moles of HNO3?
Answer:
126 grams
Explanation:
What is the mass of two moles of HNO3?
H = 1g/mole = 1+
N = 14g/mole = 3-
O = 16g/mole = 2-
HNO3 = 63g/mole
Classify the following as an element, compound, homogeneous mixture, or heterogeneous
mixture: salt water
A. Element
B. Compound
C. Homogeneous mixture
D. Heterogenous mixture
Plz help me with this question
A skeleton chemical equation includes which of the following
Answer:
Explanation:
Skeleton equations are also known as unbalanced equations.
Eg I react Oxygen, Hydrogen and Chlorine and I get Water and Chlorine Gas
H2 + Cl2 = HCl
Left Side
H = 2
Cl = 2
Right Side
H = 1
Cl = 1
As you can see it's not balanced is skeleton equation.
What’s one renewable energy resource that can be used instead of fossil fuels ?
Answer:
Solar Energy & Wind Energy
Explanation:
These are renewable energy and can be used used in replacement for fossil fuels.
PLS MARK ME AS BRAINLIEST!!
.
Showing a correct numerical setup, determine the percent composition by mass of carbon in baking soda (gram-formula mass - 84 grams per mole).
Answer:
Percentage Mass carbon = 14.3%
Explanation:
Baking soda which is sodium hydrogen bicarbonate has the molecular fomula, NaHCO3.
Atomic masses of each of the component atoms is, Na = 23; H = 1; C = 12; O = 16
Step 1: Molar mass of NaHCO3 = 23 + 1 + 12 + 3*16 = 84 g/mol
Step 2: Percentage mass of Carbon = (atomic mass of Carbon / molar mass of NaHCO3) * 100%
= (12 / 84) *100%
Percentage Mass of carbon = 14.3%
How are electrons and positrons the same, and how are they different?
Answer:
A positron is the antimatter counterpart of an electron (also called anti-electron). ... The spin, a type of angular momentum carried by the electron and positron, is the same for both. However, the electron and positron have the opposite charge. The electron has a negative charge, and the positron has positive charge.
) carbon + oxygen = _____________
E) calcium carbonate = ______________ + _________________
F) carbon + hydrogen = ____________
G) carbon + hydrogen + oxygen = ______________
H) water = ___________ + ___________
I) Iron + sulphur = _______________
J) magnesium + oxygen = ________________
M) magnesium oxide + water = ___________________
O) carbon monoxide + oxygen = ______________
Answer:
d)carbon(iv)oxide/carbon(ii)oxide
e)Calcium,carbon,oxygen
f)carnonhydride
g)Carbonhydrate
h)hydrogen+oxygen
I)Iron sulphide
j)Magnesiumoxide
m)magnesium hydroxide+hydrogen gas
d)carbon dioxide
What does Avogadro's law say about a gas atSTP? A; 1 L of any gas contains 22.4 moles at STP B; 1 L of any gas has a pressure of 22.4 atm at STP C; All gases are at 22.4 atm at STP D; 1 mole of any gas has a volume of 22.4 L at STP
Answer: 1 mole of any gas has a volume of 22.4 L at STP
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
According to ideal gas equation:
[tex]PV=nRT[/tex]
P = pressure of gas = 1 atm (at STP)
V = Volume of gas = ?
n = number of moles = 1
R = gas constant =[tex]0.0821Latm/Kmol[/tex]
T =temperature =[tex]273K[/tex] (at STP)
[tex]V=\frac{nRT}{P}[/tex]
[tex]V=\frac{1mol\times 0.0820 L atm/K mol\times 273K}{1atm}=22.4L[/tex]
Thus 1 mole of every gas occupies 22.4 L at STP
Answer:
1 mole of any gas has a volume of 22.4 L at STP
Explanation:
ap3xx
Based on the Lewis/electron dot representation
of the two atoms, predict the ratio of metal
cationic (+) atom to nonmetal anionic (-) atom in the compound
Answer:
A. 1:3
Explanation:
If we look at the ions shown in the image attached to the question, we will notice that we have aluminum (Al^3+), a trivalent ion combining with the iodide ion (I^-).
Aluminum can easily give out its three outermost electrons to three atoms of iodine. If aluminum gives out its three electrons, it achieves the stable octet structure. Iodine atoms have seven electrons in their outermost shell. They only need one more electrons to complete their octet. This one electron can be gotten by the combination of three iodine atoms with one atom of aluminum. One electron each is transferred from the aluminum atom to each iodine atom to form AlI3 with a ratio of 1:3.
Lewis dot structure is a diagrammatic representation of valence electrons in an atom of a molecule.
The ratio of the cations to anions in the given compound is 1:3.
In the given figure, Aluminum has 3 electrons, which can be donated to iodine. Aluminum has atomic number 13, this means that if the element donates three electrons then it will attain a stable electronic configuration.
In the Iodine atom, each iodine needs only one electron to complete its octet. Thus, three atoms of iodine will be required to gain electrons from aluminum.
Thus, the ratio cation to the anion is 1:3.
To know more about lewis dot structure, refer to the following link:
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What is the name of the body part that passes messages
from the sensory neurons to the brain?
o Lungs
O Nerve Cells
o Brain
o Stimulus please help me thanks
What is the energy of light with a wavelength of 652 nm? (The speed of light in a vacuum is 3.00 x 108 m/s, and Planck's constant is 6.626 x 10-34 J·s.)
O A 3.05 x 10-²⁸ j
O B. 3.28 x 10¹⁸ j
O C. 3.05 x 10-¹⁹ j
D. 3.28 x 10²⁷ j
A and C have negative exponents pleas help me
Answer:
C. 3.05 x 10⁻¹⁹ J
Explanation:
Given;
wavelength of the light, λ = 652 nm = 652 x 10⁻⁹ m
speed of light, c = 3.00 x 10⁸ m/s
Planck's constant, h = 6.626 x 10⁻³⁴J·s
Energy of electromagnetic wave is calculated as;
E = hf
where;
f is frequency of the light wave
f = c / λ
[tex]E = hf = h\frac{c}{\lambda} \\\\E = \frac{hc}{\lambda} \\\\E = \frac{6.626*10^{-34}*3*10^8}{652*10^{-9}} \\\\E = 3.05*10^{-19} \ J[/tex]
Therefore, the energy of the light is 3.05 x 10⁻¹⁹ J
The correct option is "C"
C. 3.05 x 10⁻¹⁹ J
Answer:
Option C. 3.05 x 10¯¹⁹ J
Explanation:
Step 1:
Data obtained from the question.
wavelength (λ) 652 nm = 652x10^–9m
Velocity of light (v) = 3.00x10^8 m/s
Planck's constant (h) = 6.626x10^-34J·s
Step 2:
Determination of the frequency of the light.
The frequency can be obtained as follow
v = λf
3x10^8 = 652x10^–9 x f
Divide both side by 652x10^–9
f = 3x10^8 / 652x10^–9
f = 4.6x10^14s¯¹
Step 3:
Determination of the energy of the light wave.
This can be obtained as follow:
Planck's constant (h) = 6.626x10^-34J·s
Frequency (f) = 4.6x10^14s¯¹
Energy (E) =..?
E = hf
E = 6.626x10^-34 x 4.6x10^14s¯¹
E = 3.05 x 10¯¹⁹ J
A beaker contains 41.3 mL of pentane ( C5H12 , density is 0.626 g/mL). Determine how many C atoms this liquid contains.
Answer:
41.3 mL OF PENTANE CONTAINS 62.608 *10^-27 CARBON ATOMS.
Explanation:
Volume of Pentane = 41.3 mL
Density = 0.626 g/mL
Since density is defined as mass per unit volume. Calculate the mass:
Density = mass / volume
Mass = density * volume
Mass = 0.626 g/mL * 41.3 mL
Mass = 0.015 g of pentane
Molar mass of pentane C5H12 = ( 12* 5 + 1*12) = 60 + 12 = 72 g/mol
Number of moles = mass / molar mass
Number of moles = 0.015 g / 72 g/mol
Number of moles = 2.08 * 10^-4 moles.
Since 1 mole of pentane contains 5 moles of carbon, we can then calculate how many moles of csrbon 2.08*10^-4 moles will contain
1 mole of pentane = 5 moles of carbon
2.08 *10^-4 moles = x moles
x mole = 5 * 2.08*10^-4
x mole = 10.4 *10^-4 moles of carbon
In other words, 10.4*10^-4 moles of carbon is present in 41.3 mL of pentane
We can then calculate the number of carbon atoms present in the liquid using:
From 1 mole containing 6.02 *10^-23 atoms, 10.4 *10^-4 moles of pentane will contain:
1 mole = 6.02*10^-23 atoms
10.4 *10^-4 moles = (6.02*10^-23 * 10.4 *10^-4) atoms of pentane
= 62.608 *10 ^-27 atoms of pentane.
So therefore, 41.3 mL of pentane will contain 62.608 * 10 ^-27 carbon atoms
The number of C atoms in 41.3 mL of pentane (C₅H₁₂) of density 0.626 g/mL is 2.16x10²³.
To find the number of C atoms in pentane, we need to find the number of moles.
We can calculate the mass from the density:
[tex] d = \frac{m}{V} [/tex]
Where:
d: is the density = 0.626 g/mL
V: is the volume = 41.3 mL
The mass is:
[tex] m = d*V = 0.626 g/mL*41.3 mL = 25.85 g [/tex]
Now, with the molecular weight of the pentane, we can calculate the number of moles:
[tex] \eta = \frac{m}{M} = \frac{25.85 g}{72.15 g/mol} = 0.358 \:moles [/tex]
The number of C atoms can be found with Avogadro's number:
[tex] n_{C} = \frac{6.022\cdot 10^{23} \:atoms}{1\:mol}*0.358 \:moles = 2.16 \cdot 10^{23} \:atoms [/tex]
Therefore, the liquid contains 2.16x10²³ C atoms.
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I hope it helps you!
In 450 BCE, Greek philosopher Democritus first thought of the existence
of tiny particles that compose everything around us. He named them
'atomos', meaning
A. Invisible
B. Particle
C. Indivisible
D. None of these
Reset Selection
Answer:
A. Invisible
Explanation:
Answer: Indivisible
Explanation: There was a brilliant philosopher named Democritus, and he proposed the Greek word atomos, which means uncuttable.
Synonyms for uncuttable are as follows:
Joined, inseparable, Indivisible, unbreakable, irreducible, impenetrable, unalterable, indissoluble, unified, permanent, immutable and unchangeable.
Why other answers are wrong:
I simply believe the other user may have had a minor typo which caused such confusion. Who knew one letter could effect an answer that much XD
what element must combine with the metal for oxidation to take place?
An iron nail with a mass of 12 grams absorbs 12 Joules of heat. If the nail was initially at 25°C, what is the final temperature?
Where do food molecules for cecropia trees come from?
Answer:
Central and South American forests.
Explanation: https://brainly.in/question/7540305
As much sugar as will dissolve is added to hot water. The water is then
cooled, and all of the sugar remains dissolved in the solution. Which term
describes the final sugar solution?
O A. Nonsaturated
O B. Saturated
C. Unsaturated
O D. Supersaturated
Count then plot the total number of atoms in the reactants to total atoms
in the products for the equation 2H2 + O2 + 2H2O
hi:) how to do 2(bi)?
Answer:
4 protons, 5 neutrons, 2 electrons
Explanation:
If you look at the numbers beside Be²⁺, the number 9 is the relative atomic mass and the number 4 is the proton (atomic) number. The relative atomic mass is the sum of the number of protons and the number of neutrons.
Number of protons= proton number.
Hence, number of protons= 4
Number of protons + neutrons= 9
4 + number of neutrons= 9
number of neutrons
= 9 -4
= 5
In an atom, the number of protons and electrons are the same since atoms are electrically neutral. But in an ion, the number of electrons is not equal to the number of protons since the atom gains/ loses electrons to form an ion. A positive sign means that electrons are given away.
Thus, Be gives away 2 electrons to form Be²⁺.
Original number of electrons= 4
Number of electrons in Be²⁺
= 4 -2
= 2
In summary, the number of protons and neutrons in an ion is the same as that of the atom. However, the number of electrons is not the same.
Answer:
Answer:
4 protons, 5 neutrons, 2 electrons
Explanation:
If you look at the numbers beside Be²⁺, the number 9 is the relative atomic mass and the number 4 is the proton (atomic) number. The relative atomic mass is the sum of the number of protons and the number of neutrons.
Number of protons= proton number.
Hence, number of protons= 4
Number of protons + neutrons= 9
4 + number of neutrons= 9
number of neutrons
= 9 -4
= 5
In an atom, the number of protons and electrons are the same since atoms are electrically neutral. But in an ion, the number of electrons is not equal to the number of protons since the atom gains/ loses electrons to form an ion. A positive sign means that electrons are given away.
Thus, Be gives away 2 electrons to form Be²⁺.
Original number of electrons= 4
Number of electrons in Be²⁺
= 4 -2
= 2
In summary, the number of protons and neutrons in an ion is the same as that of the atom. However, the number of electrons is not the same.
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