The change in energy when the electron drops to the ground state can be calculated. The wavelength of the released photon can be determined using the equation: wavelength = hc / energy.
Explanation:When an electron drops from a higher energy level to the ground state, it releases energy in the form of a photon. The change in energy can be calculated by taking the difference between the initial energy and the energy of the ground state. The wavelength of the photon can be determined using the equation:
wavelength = hc / energy
where h is Planck's constant (6.626 x 10^-34 J s), c is the speed of light (3.00 x 10^8 m/s), and energy is the change in energy calculated earlier.
Describe three advantages nuclear fusion would have over nuclear fission.
In nuclear fission reaction a heavy nuclei breaks apart into two lighter nuclei and in fusion reaction two lighter nuclei fuse to form a heavy nuclei. Nuclear fusion produces tremendous amount of energy which is several times the amount produced by any nuclear fission reaction. It is the nuclear fusion reaction that powers the sun. Nuclear fission produces radioactive, toxic waste which nuclear fusion does not. The resources of nuclear fusion are abundantly available on Earth, such as lithium and hydrogen isotopes.
A certain element forms an ion with 10 electrons and a charge of +2. identify the element.
Answer:
Mg (Magnesium)
Explanation:
Pearson Chemistry Question (Ions and the Periodic Table)
What is the kinetic energy of the emitted electrons when cesium is exposed to UV rays of frequency 1.3×1015Hz?
To calculate the kinetic energy of the emitted electrons when cesium is exposed to UV rays with a frequency of 1.3×1015Hz, first, determine the photon's energy using Planck's equation, then subtract cesium's work function. The result is approximately 5.1938×10-19 J, illustrating an application of the photoelectric effect.
Explanation:To find the kinetic energy of the emitted electrons when cesium is exposed to UV rays of frequency 1.3×1015Hz, we first need to calculate the energy of the incident UV photons using Planck's equation: E = hf. Here, h is Planck's constant (6.626×10-34 Js), and f is the frequency of the UV rays.
E = (6.626×10-34 Js)(1.3×1015Hz) = 8.6138×10-19 J per photon
The work function φ (phi) of cesium, which is the minimum energy required to remove an electron from its surface, is approximately 2.14 eV, or 3.42×10-19 J. The kinetic energy (KE) of the emitted electrons can be found by subtracting the work function from the energy of the incident photons: KE = E - φ.
Therefore, the kinetic energy of the emitted electrons is approximately (8.6138 - 3.42)×10-19 J = 5.1938×10-19 J.
The calculation above shows how to determine the kinetic energy of photoelectrons ejected from materials like cesium when exposed to UV radiation with a specific frequency, using concepts from the photoelectric effect.
A 10.0 gram piece of metal is placed in an insulated calorimeter containing 250.0 grams of water initially at 20.0°c. if the final temperature of the mixture is 25.0°c, what is the heat change of piece of metal? 5230 j â5230 j 209 j â209 j 5440 j
List and describe the steps of the scientific method.
Which element would release the most energy while adding an electron to a neutral atom in the gas phase?
What are groups 1, 2, and 3 examples of on a periodic table of elements?
A) Metals
B) Nonmetals
C) Metalloids
D) Noble gass
Answer:
A) Metals
Explanation: They mainly explain metals in "periodic table" well it's in it too.
An aluminum sample has a mass of 80.01 g and a density of 2.70 g/cm3. According to the data, to what number of significant figures should the calculated volume of the aluminum sample be expressed?
Answer : The volume of aluminium sample should be [tex]29.6cm^3[/tex]
Explanation :
Density : It is defined as the mass contained per unit volume.
Formula used :
[tex]Density=\frac{Mass}{Volume}[/tex]
Given :
Mass of aluminum = 80.01 g
Density of aluminium = [tex]2.70g/cm^3[/tex]
Now put all the given values in the above formula, we get :
[tex]2.70g/cm^3=\frac{80.01g}{Volume}[/tex]
[tex]Volume=\frac{80.01g}{2.70g/cm^3}=29.6cm^3[/tex]
Therefore, the volume of aluminium sample should be [tex]29.6cm^3[/tex]
What is the atomic number of an element that has 43 protons and 50 neutrons?
You are about to perform some intricate electrical studies on single skeletal muscle fibers from a gastronemius muscle. but first, you must prepare 6l of a 170 mm nacl solution in which to bath the isolated muscle during your studies. how many grams of nacl must you weigh out on the lab balance to prepare this bath solution? (hint: the molecular weight of nacl is 58.44 grams/mole).
To prepare a 6L solution of 170 mM NaCl, you need to calculate the moles required and use the molecular weight of NaCl to convert to grams. Multiply the molarity by the volume to get moles, and then multiply by the molecular weight to get 59.6088 grams.
Explanation:To prepare a 170 mM NaCl solution, you will need to calculate the number of grams of NaCl required. First, you need to understand the concentration units. Here, 170 mM (millimolar) indicates 170 millimoles of NaCl are needed per liter of solution. To find out how many millimoles you need for 6 liters, you multiply 170 mmol/L by 6 L, yielding 1020 mmol, or 1.020 mol since 1000 mmol is equivalent to 1 mol.
Next, you use the molecular weight of NaCl, which is 58.44 g/mol, to convert moles to grams. The calculation is:
1.020 mol × 58.44 g/mol = 59.6088 gTherefore, you would need to weigh out 59.6088 grams of NaCl and dissolve it in enough water to make the total volume up to 6 liters.
Determine the number of atoms in 1.70 ml of mercury. (the density of mercury is 13.5 g/ml.)
To determine the number of atoms in 1.70ml of mercury, we have to determine the moles of mercury.
First find the mass in grams by using the formula:
Mass = volume x density
(1.70 mL Hg) x (13.5 g/mL) = 22.95 g Hg
Now find number of moles;
(22.95 g Hg) x (1 mol Hg/200.59 g/mol) = 0.1144 mol
Hg
For number of atoms multiply with Avogardro's number that is 6.023 x 10²³
(0.1144 mol Hg) x (6.023 x 10²³ atoms/mol) = 6.89
x 10²² atoms Hg
So, there is 6.89 x 10²² atoms of mercury are present in 1.70ml of mercury.
Which of the halide ions (f−, cl−, br−, and i−) is the most stable base? which is the least stable base?
Explanation:
It is known that on moving down a group there will occur a decrease in electronegativity of non-metals. Whereas stability of their conjugate bases increases on moving down the group.
This also means that their acid strength also increases.
For example, [tex]HX + H_{2}O \rightarrow H_{3}O^{+} + X^{-}[/tex]
where, X = F, Cl, Br or I)
Therefore, acidity will increase in the following order.
HI > HBr > HCl > HF
Hence, the stability of their conjugate bases will be as follows.
[tex]I^{-} > Br^{-} > Cl^{-} > F^{-}[/tex]
Thus, we can conclude that the most stable base is [tex]I^{-}[/tex] and least stable base is [tex]F^{-}[/tex].
Where on the periodic table are the majority of radioactive isotopes found?
In the d- block of the periodic table are the majority of radioactive isotopes found.
Periodic table is a tabular arrangement of elements in the form of a table. In the periodic table, elements are arranged according to the modern periodic law which states that the properties of elements are a periodic function of their atomic numbers.
It is called as periodic because properties repeat after regular intervals of atomic numbers . It is a tabular arrangement consisting of seven horizontal rows called periods and eighteen vertical columns called groups.
As radioactive isotopes are between atomic numbers 84 and 118 the majority of them are found in the d-block of the periodic table.
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Radioactive isotopes are largely found in heavier elements of the periodic table, specifically in the uranium, actinide, and thorium series. Elements after atomic number 83 are inherently unstable and tend to be radioactive due to additional neutrons in their nuclei enforcing instability and resulting in radioactive decay.
Explanation:
The radioactive isotopes are primarily found in the heavier elements of the periodic table. Notably, they occur in the uranium series, the actinide series, and the thorium series. Any elements beyond atomic number 83 (Bismuth) on the periodic table are inherently unstable and tend to be radioactive. For instance, Technetium (element 43) and Promethium (element 61), and most of the elements with atomic number 84 (Polonium) and higher consist entirely of unstable, radioactive isotopes. This instability is due to the additional neutrons they possess that tend to make their nuclei unstable and thereby undergo radioactive decay. Radioactive decay is characterized by the loss of one or more neutrons and the release of energy.
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What would you predict is worse based on your knowledge of quantum theory - a weak beam of ultraviolet light, or an intense beam of infrared light?
Answer : Amongst the given choices a weak beam of ultraviolet light is considered to be the worst as compared to others.
The wavelength of UV light is from 10 nm to 400 nm, and its energy varies from 3 eV to 124 eV.
As a single beam of UV light will have much energy in each photon which is emitted. The damage done by UV rays is observed to be very harmful in human cells and may cause many diseases. UV rays can also damage the eyes as more than 99% of UV radiation is absorbed by the front of the eyes. It can also lead to ultimate blindness. Therefore, it is considered to be much worse than an intense beam of infrared light.
Draw the structure of a compound with molecular formula c5h12 that exhibits only one kind of proton (all 12 protons are chemically equivalent).
The compound C5H12 with only one kind of proton is pentane, a straight-chain alkane with five carbon atoms. There's no functional group to create a chemically different environment for the hydrogen atoms, hence all 12 protons are chemically equivalent.
Explanation:The compound with a molecular formula C5H12 that exhibits only one kind of proton (all 12 protons are chemically equivalent) is the linear form of pentane. This is a straight-chain alkane with five carbon atoms, where each carbon atom is single-bonded to its neighbors and the remaining bonding spots are filled with hydrogen atoms. Here is how the structure of pentane is represented:
-CH3CH2CH2CH2CH3-
The reason it exhibits only one kind of proton is because there is no functional group that can create a chemically different environment for the hydrogen atoms, making all 12 protons chemically equivalent.
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What kind of reaction adds water to break large molecules into subunits?
If you add MeOH to CoCl2(Alc)2, the CoCl2(Alc)2 concentration will change. What are the two reasons for this concentration change?
The si standard of mass is the 1 kilogram international prototype kilogram stored in a vault in the basement of the international bureau of weights and measures in sevres, france. it is composed of an alloy that is 90% platinum and 10% iridium; having a density of 21.186 g/cm3. what is the volume of the standard kilogram?
Formaldehyde, ch2o, is used as an embalming agent. draw the structure of ch2o including lone pairs.formaldehyde, ch2o, is used as an embalming agent. draw the structure of ch2o including lone pairs.formaldehyde, ch2o, is used as an embalming agent. draw the structure of ch2o including lone pairs.
The structure of formaldehyde (CH2O) features a carbon atom double-bonded to an oxygen atom with two lone pairs, and two hydrogen atoms single-bonded to the carbon, resulting in a trigonal planar molecular geometry with bond angles around 120°.
Explanation:Formaldehyde, with the chemical formula CH2O, is a simple aldehyde commonly used as an embalming agent and preservative. In its Lewis structure, the carbon atom is double-bonded to the oxygen, which also has two lone pairs of electrons, creating a region of high electron density. This double bond contributes to the molecule's trigonal planar geometry, with bond angles close to 120°. Each of the two hydrogen atoms is single-bonded to the carbon atom, completing the tetrahedral geometry around the carbon atom. The molecular structure is depicted as:
:O:
H-C-H
The oxygen atom has two lone pairs of electrons, and there are three regions of bonding around the carbon atom, which has no lone pairs, providing an acceptable Lewis electron structure for formaldehyde.
Etahnol has a density of 0.79 g/mL. What is the volume, in quarts, of 1.65 kg of alcohol?
Using the mass of a proton 1.0073 amu and assuming it's diameter is1.0x10^-15, calculate the density of a proton in g/cm^3. I'm not sure about how to convert amu to grams. Thanksfor the help!!
A substance undergoes a change. Which of the following indicates that the change was a chemical change? The substance changed shape. New molecules formed. The substance froze. The substance changed size.
Answer: New molecules formed.
Explanation:
A physical change is defined as the change in which shape, size will be altered. No new substance gets formed in these reactions.
A chemical change is defined as the change in which chemical composition is altered. A new substance is formed in these reactions.
The substance changed shape is a physical change.
The substance froze means the state is changed and is a physical change.
The substance changed size is a physical change.
Thus when new molecules are formed, it is a chemical change.
When solid potassium chlorate is heated, it decomposes to form solid potassium chloride and oxygen gas. express your answer as a balanced chemical equation. identify all of the phases in your answer?
A solution of cough syrup contains 5.00% active ingredient by volume. If the total volume of the bottle is 11.0 mL , how many milliliters of active ingredient are in the bottle?
Taking into account the definition of percentage in volume, 0.55 mL of active ingredient are in the bottle.
In first place, every solution consists of two classes of components: the solvent and the solute.
The solvent of a solution is the component that is capable of dissolving others and is usually the component present in greater quantity.
The solute is the component that is dissolved in the solvent and is usually present in smaller quantities. A solution can contain more than one solute.
On the other side, the concentration of a solution is the amount of solute in a given amount of solution.
The percentage in volume (% v / v) is a measure of the concentration that indicates the volume of solute per 100 units of volume of the solution and can be calculated mathematically by means of the expression:
[tex]percentage in volume=\frac{solute volume}{solution volume}x100[/tex]
In this case:
percentage in volume= 5 %solute volume= ?solution volume= 11 mLReplacing in the expresion for percentage in volume:
[tex]5=\frac{solute volume}{11 mL}x100[/tex]
Solving:
5× 11 mL= solute volume×100
55 mL=solute volume×100
55 mL÷100= solute volume
0.55 mL= solute volume
Finally, 0.55 mL of active ingredient are in the bottle.
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https://brainly.com/question/1713808https://brainly.com/question/14571931?referrer=searchResultsTo find the amount of active ingredient in the cough syrup, you multiply the percentage concentration (5.00%) by the total volume of the syrup (11.0 mL) and divide by 100, yielding 0.55 mL of active ingredient.
Explanation:To calculate the amount of active ingredient in a cough syrup solution, we use the percentage concentration by volume, which in this case is 5.00% v/v. This means that for every 100 mL of the total solution, there are 5 mL of the active ingredient. Given that the total volume of the cough syrup bottle is 11.0 mL, we can determine the volume of active ingredient using the following calculation:
Volume of active ingredient = Percentage concentration × Total volume / 100
Volume of active ingredient = 5.00% × 11.0 mL / 100 = 0.55 mL
Therefore, there are 0.55 milliliters of active ingredient in the 11.0 mL bottle of cough syrup.
Draw two lewis structures for a compound with the formula c4h10. no atom bears a charge, and all carbon atoms have complete octets.
The valence shell electrons of a molecule are shown in an extremely simplified manner by a Lewis structure.
Butane is an alkane represented by C4H10. All the bonds in this situation are single bonds, since this substance is an alkane. Two shared electrons are present in every bond. Each carbon atom requires 8 electrons around it in order to follow the octet rule.
The octet rule was fulfilled by the hydrogen bonds, eliminating the necessity for the electron dots. Straight-chained butane is the initial structure. The y-chained isobutane is the second structure.
The Lewis structures for a compound with the formula C₄H₁₀ is attached in the image below.
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Helium has a density of 1.79 x 10-4 g/mL at standard temperature and pressure. A balloon has a volume of 6.3 liters. Calculate the mass of helium that it would take to fill the balloon.
35,000 g
1.1 x 10-3 g
2.8 x 10-5 g
1.1 g
The mass of helium that it would take to fill the balloon is 1.1 grams.
What is the relation between mass and density?Relation between the mass of any substance and their density will be represented as:
Density = Mass / Volume
Given that,
Density of helium gas = 1.79 × 10⁻⁴ g/mL
Volume of balloon in which gas is present = 6.3L = 6300 mL
On putting all these values, we get
Mass = (1.79 × 10⁻⁴ g/mL)(6300mL) = 1.12 grams
Hence required mass of helium is 1.1 g.
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Write the symbol for the ion formed when each element gains electrons and attains a noble-gas electron configuration. Br, H, Se.
Explanation:
When an atom gain electrons then it acquires a negative charge whereas when an atom loses electrons then it acquires a positive charge.
For example, atomic number of bromine is 35 and its electronic distribution is 2, 8, 18, 7. So, in order to gain stability bromine accepts one electrons and thus it acquires a negative charge as [tex]Br^{-}[/tex].
Therefore, the symbol for the ion formed when each given element gains electrons and attains a noble-gas electron configuration are as follows.
Br changes into [tex]Br^{-}[/tex].H changes into [tex]H^{-}[/tex].Se changes into [tex]Se^{2-}[/tex].
Air is 21% oxygen by volume. Oxygen has a density of 1.31 g/L. What is the volume in liters of a room that holds enough air to contain 55kg of oxygen?
Answer:
199,927.29 L is the volume air that holds enough air to contain 55 kg of oxygen.
Explanation:
Density of oxygen = 1.31 g/L
Mass of oxygen gas,m = 55 kg = 55,000 g
Volume of the oxygen gas = V
Volume of the air = [tex]V_a[/tex]
[tex]Density=\frac{Mass}{Volume}[/tex]
[tex]1.31 g/L=\frac{55,000 g}{V}[/tex]
V = 41.984.732 L
Air is 21% oxygen by volume.That is in 100 L of air 21 L of oxygen is present.
So, when oxygen gas is 41.984.732 L the volume of the air will be:
[tex]21\%=\frac{41.984.732 L}{V_a}\times 100[/tex]
[tex]V_a=199,927.29 L[/tex]
199,927.29 L is the volume air that holds enough air to contain 55 kg of oxygen.
The volume of the room that can hold enough air containing 55 Kg of oxygen is 199927.29 L
We'll begin by converting 55 kg of oxygen to grams (g). This can be obtained as follow:
1 Kg = 1000 g
Therefore,
55 kg = 55 × 1000
55 Kg = 55000 gNext, we shall determine the volume of oxygen. This can be obtained as follow:
Mass of oxygen = 55000 kg
Density of oxygen = 1.31 g/L
Volume of oxygen =?[tex]Density = \frac{mass}{volume} \\\\1.31 = \frac{55000 }{volume}[/tex]
Cross multiply
1.31 × Volume = 55000
Divide both side by 1.31
Volume = 55000 / 1.31
Volume of oxygen = 41984.73 LFinally, we shall determine the volume of the room by calculating the volume of air. This can be obtained as follow:
Volume of oxygen = 41984.73 L
Percentage of oxygen in air = 21%
Volume of air =?[tex]Percentage of oxygen =\frac{volume of oxygen}{Volume of air} * 100[/tex]
21% = [tex]\frac{41984.73}{Volume of air}[/tex]
[tex]0.21 = \frac{41984.73}{Volume of air }[/tex]
Cross multiply
0.21 × Volume of air = 41984.73
Divide both side by 0.21
[tex]Volume of air = \frac{41984.73}{0.21}\\\\[/tex]
Volume of air = 199927.29 LTherefore, we can conclude that the volume of the room that can hold enough air containing 55 Kg of oxygen is 199927.29 L
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What would you predict is worse based on your knowledge of quantum theory - a weak beam of ultraviolet light, or an intense beam of infrared light?
A biotic factor in a desert ecosystem would be the
A) humidity of the air.
B) air temperature.
C) cactus growing.
D) sandy soil.