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Related Questions
Given that hotter blackbodies produce more energy than cooler blackbodies, why do cooler red giants have much higher luminosity than much hotter red dwarfs?
Answers
Red giants are much larger than red dwarfs, which means that they have a much larger surface area and thus emit more energy. Although red giants have cooler surface temperatures than red dwarfs, their larger surface area more than makes up for the lower temperature in terms of total energy output.
The reason why red giants are much larger than red dwarfs has to do with the evolution of the star. Red giants are more evolved stars that have exhausted the hydrogen fuel in their cores, causing the core to contract and heat up, while the outer layers of the star expand and cool down. This expansion increases the star's size and surface area, leading to a higher luminosity.
Red dwarfs, on the other hand, are much smaller and cooler than red giants because they are low-mass stars that burn their fuel at a slower rate. As a result, they have longer lifetimes and remain on the main sequence longer, never undergoing the same expansion that red giants do.
I need help in this:(
Answers
Answer:
Phosphorus(P) and Oxygen(O)=Covalent bond
Chlorine(Cl) and Sodium(Na) = Ionic bond
Silver (Ag) and Silver (Ag)= Metallic bond
Phosphorus and Oxygen would be covalent bonding
Chlorine and sodium would be ionic bonding.
Round the answer of the following calculation to the correct number of significant figures;
3700 20.1 x 5.60 x 0.0407
Answers
The calculation gives the product 17000 to 2 significant figures
What are significant figures in a calculation?Significant figures in a calculation or a number refers to the number of non-zero numbers that are present in a number.
If the number contains a decimal point, the number of non-zero numbers before the decimal point gives the number of significant figures.
However, if a zero occurs between non-zero numbers, it is considered significant.
Significant figures are used in approximation to indicate to what point a set of numbers become significant.
In a calculation, the number significant figure is determined by the number which has the lowest number of significant figures.
In the given calculation, the lowest significant figure is in the numbers 3700 and 5.60
3700 × 20.1 × 5.60 × 0.0407 = 17000 to 2 significant figures
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10 kg of Phenanthrene is to be burnt with supplied air which is 30% less than the requirement. Find the
exit gas stream average molecular weight and the leftover Phenanthrene amount in the reactor.
Answers
The exit gas stream average molecular weight is 28.97 g/mol, and there will be 3.0 kg of leftover Phenanthrene in the reactor.
The balanced combustion equation for Phenanthrene is:
C₁₄H₁₀ + 21O₂ → 14CO₂ + 5H₂O
From the equation, we can see that 21 moles of oxygen are needed to combust 1 mole of Phenanthrene. Thus, to burn 10 kg of Phenanthrene, we need:
10,000 g / 178.24 g/mol = 56.05 moles of Phenanthreneand
21 * 56.05 = 1177.05 moles of O₂However, the supplied air is 30% less than the requirement, which means only 70% of the required O₂ will be supplied. Therefore, the actual amount of O₂ supplied will be:
1177.05 * 0.7 = 823.94 moles of O₂Assuming the air is mostly nitrogen, we can calculate the exit gas stream average molecular weight using the following formula:
Mw = (0.79 * 28.01) + (0.21 * 32) = 28.97 g/molwhere 0.79 and 0.21 are the mole fractions of nitrogen and oxygen in air, respectively, and 28.01 and 32 are the molecular weights of nitrogen and oxygen, respectively.
Finally, we can calculate the amount of leftover Phenanthrene in the reactor:
Amount of Phenanthrene consumed = 56.05 moles x 178.24 g/mol = 9999.72 gLeftover Phenanthrene = 10,000 g - 9999.72 g = 0.28 gHowever, this amount is negligible due to the large scale of the reaction. Therefore, we can round it off to:
Leftover Phenanthrene = 3.0 kg
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In the model with four atoms bonded to the central atom, the central atom satisfies the octet rule because it has four valence electron pairs (that is, eight valence electrons). The electron pairs are all in the form of covalent bonds.
Replace one of these bonds with a lone pair by clicking the red x to remove the atom. Then click the Lone Pair to add it.
Notice that the molecule geometry is no longer the same as the electron geometry. The electrons in the lone pair don’t count when describing the shape of the molecule. Record your observations in the second row of the table. Then repeat this process to replace another atom with a lone pair. Record the results in the third row of the table.
Select the correct option from each drop-down menu to complete the table.
Answers
Overall, it is clear that understanding the octet rule and the relationship between molecule geometry and electron geoHBased on the given information, it is clear that the central atom in the model with four atoms bonded to it satisfies the octet rule because it has four valence electron pairs, resulting in eight valence electrons. It is worth noting that these valence electrons are all in the form of covalentbonds.
owever, it is important to note that the molecule geometry is not the same as the electron geometry. This is because the electrons in the lone pair do not count when describing the shape of the molecule. As such, it is crucial to record observations in the second row of the table.
metry is crucial in accurately analyzing and describing molecular structures. By following the steps outlined above, one can effectively record observations and analyze the structure of various mole
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Hekehwkhekehekhdkfnflebkdkfbrkebekebe
Answers
Hsvhpsvuwgycwhusvywgogwitcsuovsigsviyscyisvyos
answer the question in the file. it is to name the alkane
Answers
C16H34
Hexadecane
.........
Answer:
6-ethyl-6,7-dimethyl-3-propylnonane
Explanation:
Step 1: Select the longest carbon chain.
The one with 9 carbons is the longest carbon chain. (Refer to the attached file)
So, this chain is the parent name.
Prefix for 9 carbons : Non-
Suffix used : -ane (Since all the carbons are singly bonded)
Parent name: Nonane
Step 2: Refer to side chains/branches now:
Branch 1: Ethyl on Carbon-6 (6-ethyl)
Branch 2: Methyl on Carbon 6 and 7 (6,7-dimethyl)
"di" because we have 2 methyl
Branch 3: Propyl on Carbon-3 (3-propyl)
While going along with alkyl side chains, we follow the alphabetic order.
So, The name of this compound is:
6-ethyl-6,7-dimethyl-3-propylnonane
\(\rule[225]{225}{2}\)
Hope this helped!
~AH1807
What is the mass of 2.49 moles of sucrose?
Answers
Answer:
Your answer will be 342 gmol.
Explanation:
Correct me if I'm wrong. Have a good day :)
A story to describe the motion on the graph
Answers
1 Starting with methane, name
write the equations involved
sharing
Correctly indicated.
the all the steps and
tetrachlorination. Remember
dections must be
all
movement
of 양
arrows
Answers
Answer:
See Explanation and image attached
Explanation:
Methane is an alkane. The most common reaction for which alkanes are known is substitution reaction. In a substitution reaction involving alkanes, , one or more atoms of hydrogen is/are replaced.
In the presence of sunlight and molecular chlorine gas, homolytic fission of Cl2 takes place leading to the production of chlorine radicals.
These radicals react with methane in several propagation steps as shown until the tetrachlorination product is finally obtained.
4. The volume of a liquid sample is measured as 15.43 L. We need to know the volume in
mL.
3.
b.
What conversion factor would be used in the calculation?
Calculate the volume in mL.
Answers
Conversion factor used to convert volume is 1L = 1000 mL.
15.43L = 15430mL
The same attribute is expressed using a unit conversion but in a different unit of measurement. For instance, time can be expressed in minutes rather than hours, and distance can be expressed in kilometers, feet, or any other measurement unit instead of miles. Measurements are frequently offered in one set of units, like feet, but are required in another set, like chains. A conversion factor is a mathematical equation that facilitates an equal exchange of feet for chains.
A conversion factor is a number that is used to multiply or divide one set of units into another. If a conversion is required, it must be done using the correct conversion factor to get an identical value.
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Why is capturing quality data and the use of analytics critical for the fire and emergency services?
Answers
Capturing quality data and using analytics are critical for the fire and emergency services to improve situational awareness, enhance resource management, improve incident management, and develop better planning and prevention strategies.
What is fire?
Fire is a chemical reaction that occurs when a fuel (such as wood, paper, or gasoline) combines with oxygen in the air, producing heat and light. The reaction is exothermic, meaning it releases energy in the form of heat and light. Fire requires three elements to exist: fuel, oxygen, and heat. These elements are often referred to as the "fire triangle."
Capturing quality data and using analytics are critical for the fire and emergency services for several reasons:
Improved situational awareness: Fire and emergency services need accurate, up-to-date information to make informed decisions and respond effectively to emergencies.
Enhanced resource management: Fire and emergency services often operate under tight budget constraints and need to make the most of their resources.
Improved incident management: The ability to capture and analyze data in real-time can help fire and emergency services manage incidents more effectively.
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ora
If a student is combining two
substances and sees bubbles and
is probably taking
fizzing, a
place.
A. chemical change
B. physical change
Answers
Answer:
A a chemical change
Explanation:
because a chemical change is when you mix tow substance together and they creat a new substance
Many people have said that cold water boils faster than hot water. This is not true. In fact, it’s been said so many times that most people believe it to be a fact. Postulate a reason for why this may have been thought to be true. Is there any scientific evidence backing this claim at all? Please explain your reasoning.
Answers
The claim that cold water boils faster than hot water is not true. The reason why this misconception may have emerged is likely due to a misunderstanding or misinterpretation of certain observations. However, there is no scientific evidence supporting this claim.
One possible reason for this misconception is the notion that hot water takes longer to reach its boiling point because it starts at a higher temperature. When comparing hot and cold water in terms of reaching the boiling point from room temperature, the cold water may appear to boil faster.
However, this is simply because the hot water has already gained a head start in terms of temperature. In reality, once both liquids reach their respective boiling points, the hot water will boil first.
Scientifically, the boiling point of water is determined by its temperature and pressure. Under normal atmospheric conditions, the boiling point of water is 100 degrees Celsius (212 degrees Fahrenheit). Heating water raises its temperature, and once it reaches 100 degrees Celsius, it transitions into the gaseous state. The initial temperature of the water does not affect the boiling point itself.
In conclusion, the claim that cold water boils faster than hot water is a misconception. It likely arose from a misinterpretation of observations, and there is no scientific evidence to support this claim. The boiling point of water is solely determined by its temperature and pressure, regardless of whether the water is initially hot or cold.
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An atom of an element has neutral change because the..........
Answers
Answer:
They contain equal quantities of positively charged protons and negatively charged electrons
Explanation:
Atoms are electrically neutral because they contain equal quantities of positively charged protons and negatively charged electrons. Electrons and protons have equal but opposite charges, so the result is no net charge.
If a snail crawls 55 inches per day, how many centimeters will he crawl in 23 days?
Group of answer choices
5.0X102 cm
1.06 cm
3.2X103 cm
6.1 cm
2.0X10-3 cm
Answers
If a snail crawls 55 inches per day ,the snail will crawl approximately \(3.2 * 10^3 centimeters.\)
To convert inches to centimeters, we need to use the conversion factor: 1 inch = 2.54 centimeters.
First, let's calculate the distance the snail crawls in inches in 23 days. We can multiply the daily distance by the number of days:
Distance in inches = 55 inches/day × 23 days = 1265 inches.
Now, to convert the distance from inches to centimeters, we multiply the distance in inches by the conversion factor:
Distance in centimeters = 1265 inches × 2.54 cm/inch = 3215.1 cm.
Rounding to the appropriate number of significant figures, the snail will crawl approximately 3215 cm or \(3.2 * 10^3 centimeters.\) in 23 days.
Therefore, the answer is Option 3:\(3.2 * 10^3 centimeters.\)
This means that in 23 days, the snail will crawl approximately\(3.2 * 10^3 centimeters.\)
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Why is NO3 constant in constant in chemistry
Answers
Answer:
The rate and equilibrium constants for the reaction NO3• + Cl- ⇄ NO3- + Cl• in aqueous solutions were measured by pulse radiolysis. The formation and decay of the nitrate radical, NO3•, and the dichloride radical anion, Cl2•-, in irradiated aqueous solutions containing nitric acid and chloride ions were followed under various conditions.How much heat must be added to a 34.2 g sample of aluminum in order to raise the temperature of the aluminum 34 oC? (The specific heat of Aluminum is 0.9 J/g oC)
Answers
The amount of heat required to raise the temperature of the 34.2 g sample of aluminum by 34 oC is 1043.52 J.
What is Temperature?
Temperature is a measure of the average kinetic energy of the particles in a substance. It is a physical property that determines the direction of heat flow between two objects or systems in contact with each other. Temperature is measured in degrees Celsius (°C) or Fahrenheit (°F), or in kelvin (K) in the International System of Units (SI).
The amount of heat (q) required to raise the temperature of a substance can be calculated using the formula:
q = m x c x ΔT
Where:
m = mass of the substance (in grams)
c = specific heat of the substance (in J/g oC)
ΔT = change in temperature (in oC)
Plugging in the values given:
m = 34.2 g
c = 0.9 J/g oC
ΔT = 34 oC
q = (34.2 g) x (0.9 J/g oC) x (34 oC)
q = 1043.52 J
Therefore, the amount of heat required to raise the temperature of the 34.2 g sample of aluminum by 34 oC is 1043.52 J.
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Name each of the following Acids and BasesHI
Answers
So,
We're going to name the acid with formula:
\(HI\)This compound can be called as:
- hydrogen iodide
- hydroiodic acid
Which is a strong acid that is used to prepare iodides by reaction with metals or their oxides, hydroxides, and carbonates.
An atom of oxygen has six electrons in its outermost ring and requires two more to become stable. What is the valence number of oxygen? Question 5 options: +6 +2 –2 –6
+6
+2
–2
–6
Answers
Answer: -2
EXPLANATION
Valence refers to the number of electrons that an atom must borrow or lend to complete its outermost shell. An atom of oxygen wants to add two more electrons to complete its outer shell of eight electrons. Since doing so would result in the oxygen atom becoming negatively charged by accepting two more electrons, oxygen is said to have a valence -2
-2
this is the answer
A solution of dextrose contains 25.0 g solute in 250.0 g water. How should the percentage by mass of dextrose in this solution be calculated?
Answers
Answer:
9.10% dextrose
Explanation:
To find the mass percent, you need to use the following equation:
mass (g) of solute
Mass Percent = --------------------------------- x 100%
mass (g) of solution
You can plug the given values into the equation and solve to find the mass percent of dextrose. But first, you need to calculate the mass of the solution.
Mass (solute): 25.0 g
Mass (solution): 250.0 g + 25.0 g = 275 g
25.0 grams
Mass Percent = ------------------------ x 100%
275 grams
Mass Percent = 0.0909 x 100%
Mass Percent = 9.10%
A solution of dextrose contains 25.0 g solute in 250.0 g water. 9.10% is the percentage by mass of dextrose in this solution.
A component's concentration in a combination or compound can be expressed as a mass percent, also known as a weight percent. It shows how much of the total mass of the solution or mixture is made up of the solute's (component's) mass. In chemistry, mass percent is frequently employed and stated as a percentage.
Mass Percent = mass (g) of solute/ mass (g) of solution x 100%
Mass (solute): 25.0 g
Mass (solution): 250.0 g + 25.0 g = 275 g
Mass Percent =25.0 grams / 275 grams x 100%
Mass Percent = 0.0909 x 100%
Mass Percent = 9.10%
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the most likely explanation for the increase in average beak size of the medium ground finch is that the
Answers
Answer:
Well according to the Law of Evolution, depending on where the Finch lives and what it eats depends on it's beak size. For example, if a Finch lives on the coast and eats small fruits it will have a short and stubby beak to peck at the fruits, but if the Finch ate crabs it's beak would be long to swoop down and pluck up crabs.
Hope this helps!
What is culture?
A. A society's collective knowledge, customs, and achievements
B. The traditions and practices followed by every human on Earth
OC. The traits and behaviors that humans have but animals do not
D. A group of people united by blood and marital relationships
SUDI
Answers
Answer:
A. society's collective knowledge, customs, and achievements
How many moles of carbon dioxide gas is there when 2.3g of sodium bicarbonate decomposes
to produce carbon dioxide and sodium hydroxide? NaHCO3 à NaOH + CO2
Answers
Total, 0.0137 moles of carbon dioxide gas is produced when 2.3 g of sodium bicarbonate decomposes to produce carbon dioxide and sodium hydroxide.
To determine the number of moles of carbon dioxide gas produced, we first need to find the balanced chemical equation for the reaction;
2NaHCO₃ → Na₂CO₃ + CO₂ + H₂O
From this equation, we can see that for every 2 moles of sodium bicarbonate, 1 mole of carbon dioxide is produced.
Next, we need to calculate the number of moles of sodium bicarbonate in 2.3 g using its molar mass;
molar mass of NaHCO₃ = 84.0066 g/mol
moles of NaHCO₃ = mass/molar mass
= 2.3 g / 84.0066 g/mol = 0.0274 mol
Finally, we can use the mole ratio from the balanced equation to find the number of moles of carbon dioxide produced;
moles of CO₂ = (0.0274 mol NaHCO₃) x (1 mol CO₂ / 2 mol NaHCO₃)
= 0.0137 mol CO₂
Therefore, 0.0137 moles of carbon dioxide gas is produced.
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Each of the following statements describes an intermolecular force. For each statement indicate if it describes London Forces (L), dipole forces (D); or hydrogen bonding (H): occurs in all molecules occurs in polar molecules is the strongest intermolecular force is affected by the shape of molecule occur when temporary dipole is formed occurs in molecules where hydrogen is covalently bonded t0 0, N, or F strength of the force depends on how many protons and electrons are in the molecule'
Answers
The atoms present in all molecules are bonded with some interatomic attractions. These molecular forces may be strong or weak. These attractions are known as intermolecular forces.
London forces are defined as the intermolecular forces of attraction holding molecules together. They are one of the Vander Waal's forces of attraction but are the only force present in materials that don't have polar dipole molecules . For example, among the noble gases like Ne & Ar.
Dipole–dipole forces basically, occur between molecules with permanent dipoles (i.e., polar molecules). For molecules of similar size and mass, the strength of these dipole-dipole forces increases with increasing polarity.
Hydrogen bonding is defined as the interaction involving a hydrogen atom located between a pair of other atoms having a high affinity for electrons; such a bond is usually weaker than an ionic bond or covalent bond but stronger than van der Waals forces.
The above question is inappropriate so I have answered according to general knowledge.
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Calculate the bond energy of the Br-Cl bond, in kJ/mol, using AHº for the reaction (1.6 kJ/mol) and the information in the following table Bond Bond Energy (kJ/mol)
Br - Br 193
CI - CI 243
Br - CI ?
Answers
The bond energy of the Br-Cl bond would be 217.2 KJ/mol.
\(Cl_{2}\) + \(Br_{2}\) ----> 2 Br - Cl
Δ H° reaction = (bond of energy of \(Cl_{2}\) + bond energy of \(Br_{2}\) ) - 2 (bond energy of Br - Cl)
1.6 = 243 + 193 - 2 (B.E of Br - Cl)
Bond energy of Br - Cl = 243 + 193 - 1.6 / 2 = 217.2 KJ/mol
Electrostatic forces between negatively charged electrons and positively charged atomic nuclei produce bonds. The amount of energy required to separate the atoms forming a molecular bond into free atoms is known as bond energy, and it serves as a gauge of the strength of a chemical connection.
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When 100 identical steel balls are placed on a
triple beam balance, their mass is determined to
be 1,450 grams. The mass of a single steel ball
would be closest to
Answers
Explanation:
thank you for the points
Identify the fact that is FALSE about the law of conservation of energy?
Answers
Answer:
What are the options?
Explanation:
......
Kerry is explaining to a friend that she will be conducting a descriptive investigation. She wants to know if increasing
the size of a parachute affects a skydiver's time in the air. She plans on having skydivers drop from the same height
but with different chute sizes and comparing the data. What is unusual about the description of her scientific
investigation?
O Descriptive investigations cannot have procedures.
O This is not a descriptive investigation.
O This is not a proper scientific question.
O Descriptive investigations cannot have a question.
Answers
Answer:The answer is "this is not a descriptive investagation
Explanation:
because if you drop a 300 pound person from the same height of a 110 pound person the 300 pound person is going to fall faster because of the mass of his body. Thank you
How can u change cm to dm
Answers
So, divide the length value by 10