Imagine that you are an astronomer and you have detected a star that has a temperature of about 3700 Kelvin, and a luminosity of about 0.1. examine the H-R diagram explain what spectral class and part of its life cycle the star could be in ?
Answers
Answer:
Annie Jump Cannon entered Wellesley College in Massachusetts in 1880 to study astronomy. She became interested in stellar spectroscopy, the process of breaking light from stars down into its component colors so the various elements can be identified. After suffering from scarlet fever, which left her hearing impaired, she earned her master�s degree and then continued her studies at Radcliffe College. She became an assistant at the Harvard College Observatory, the first observatory to include women as staff members. During her career, she observed, classified, and analyzed the spectra of some five hundred thousand stars, assigning each one its place in the sequence O, B, A, F, G, K, and M. In 1911 she almost became a faculty member at Harvard but the university officials refused to promote a woman to such high status. So she became the curator of astronomical photographs, earning a salary of twelve hundred dollars a year. Finally, in 1936, Harvard hired her as a permanent faculty member. She was seventy-three years old at the time.
Annie Jump Cannon entered Wellesley College in Massachusetts in 1880 to study astronomy. She became interested in stellar spectroscopy, the process of breaking light from stars down into its component colors so the various elements can be identified. After suffering from scarlet fever, which left her hearing impaired, she earned her master�s degree and then continued her studies at Radcliffe College. She became an assistant at the Harvard College Observatory, the first observatory to include women as staff members. During her career, she observed, classified, and analyzed the spectra of some five hundred thousand stars, assigning each one its place in the sequence O, B, A, F, G, K, and M. In 1911 she almost became a faculty member at Harvard but the university officials refused to promote a woman to such high status. So she became the curator of astronomical photographs, earning a salary of twelve hundred dollars a year. Finally, in 1936, Harvard hired her as a permanent faculty member. She was seventy-three years old at the time.Astronomers now realize that everything which appears to distinguish one star from another - temperature, luminosity, size, life span -- is determined almost entirely by one factor: the star's mass. The main sequence along the HR diagram is not a singular evolutionary path, as many had thought, but a portrait of the sky at one moment in time of stars with varying masses.
Annie Jump Cannon entered Wellesley College in Massachusetts in 1880 to study astronomy. She became interested in stellar spectroscopy, the process of breaking light from stars down into its component colors so the various elements can be identified. After suffering from scarlet fever, which left her hearing impaired, she earned her master�s degree and then continued her studies at Radcliffe College. She became an assistant at the Harvard College Observatory, the first observatory to include women as staff members. During her career, she observed, classified, and analyzed the spectra of some five hundred thousand stars, assigning each one its place in the sequence O, B, A, F, G, K, and M. In 1911 she almost became a faculty member at Harvard but the university officials refused to promote a woman to such high status. So she became the curator of astronomical photographs, earning a salary of twelve hundred dollars a year. Finally, in 1936, Harvard hired her as a permanent faculty member. She was seventy-three years old at the time.Astronomers now realize that everything which appears to distinguish one star from another - temperature, luminosity, size, life span -- is determined almost entirely by one factor: the star's mass. The main sequence along the HR diagram is not a singular evolutionary path, as many had thought, but a portrait of the sky at one moment in time of stars with varying masses.Below is a version of the Hertzsprung-Russell diagram, which shows how the
Explanation:
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Related Questions
what type of indicator would you use to determine the ph of an opaque (non-clear, cloudy) substance?
Answers
Specifically we can use red and blue litmus paper, phenolphthalein, and bromothymol blue , to determine the ph of an opaque (non-clear, cloudy) substance?
What is pH ?
pH, a quantitative measure of the acidity or basicity of aqueous or other liquid solutions. Widely used in chemistry, biology, and agriculture, this term translates the concentration value of hydrogen ions (usually in the range of about 1 to 10-14 gram-equivalents per liter) into a number between 0 and 14. increase. At neutral (neither acidic nor alkaline), the concentration of hydrogen ions is 10−7 gram equivalents per liter, which corresponds to a pH of 7. Solutions below pH 7 are considered acidic. Solutions with a pH greater than 7 are considered basic or alkaline.
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Consider the development of atomic theory. The last piece of the atomic puzzle was the discovery of
A)
electrons in orbitals.
B)
the neutron in the nucleus.
C)
a dense, centrally located nucleus.
D)
the location of the electron cannot be determined.
Answers
Answer:
The answer will be B
Explanation:
Answer:
B.the neutron in the nucleus
Explanation:
What units are used to measure mass and weight?
A. Mass and weight are measured in kilograms.
B. Mass and weight are measured in newtons.
C. Mass iş measured in kilograms, and weight is measured in newtons.
D. Mass is measured in newtons, and weight is measured in kilograms.
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Answer:
the answer is A, they are measured in kilograms
Compounds are created when atoms of different elements _____.
1.form chemical bonds
2.have different chemical properties
3.form physical bonds
4.have similar chemical properties
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Answer:
1.form chemical bonds
Determine whether each change represents oxidation or reduction. 1) CH3CHO to CH3CH2OH 2) CH3OH to CH4 3) N2H4to N2 4) gain of electrons 5) NO-2 to NH3 6) NAD+ to NADH 7) CH4 to Co2 8) Ag+ to Ag
Answers
Answer:
1) oxidation
2) Reduction
3) Oxidation
4) Reduction
5) Reduction
6) Reduction
7) Oxidation
8) Reduction
Explanation:
Oxidation is said to have taken place when there is a positive change in the oxidation number while reduction is said to have taken place when there is a decrease in the oxidation number.
The change from CH3CHO to CH3CH2OH represents on oxidation reaction.
The change from CH3OH to CH4 is a reduction because the oxidation number of carbon changes from +2 to -4.
The change from N2H4to N2 is an oxidation because the oxidation number of nitrogen increases from -2 to 0.
The gain in electrons is a reduction because the gain of electron leads to a decrease in oxidation number.
The change from NO- 2 to NH3 is a reduction because the oxidation number of nitrogen changes from +4 to -3.
The change from NAD+ to NADH is a reduction since NAD+ is the oxidized form of the enzyme while NADH is the reduced form of the enzyme.
The change from CH4 to Co2 is an oxidation because the oxidation number of carbon changes from -4 to + 4.
The change from Ag+ to Ag is a reduction because it involves the gain of one electron and a consequent decrease in oxidation number.
What are two factors that can change the rate of a chemical?
Answers
Answer:
the surface area of a solid reactant.
temperature.
presence/absence of a catalyst.
This diagram illustrates the life cycle of a tomato plant. Which stage in this plant life cycle is the adult? Tomato Plant Life Cycle
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Answer:
the answer is A
Explanation:
hope it hlp
The Mass of the paper before being bumed is 50% how much mass should there be after
the paper has burned?
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0%
Explanation:
IF YOU BURNED THE PAPER THERE WILL BE ONLY ASHES
What is the mass of a 5.00 cm^3 piece of copper having a density of 8.96 g/cm^3
Answers
Answer:
44.8 g
Explanation:
Density = mass / Volume
Mass = density x Volume = 8.96x 5 = 44.8 g
quartz is generally rapidly weathered to form aluminum-rich clay minerals. true or false
Answers
The given statement, "Quartz is generally rapidly weathered to form aluminum-rich clay minerals" is false.
Quartz is a mineral composed of silicon and oxygen (silica), and it is not typically weathered to form aluminum-rich clay minerals. Quartz is highly resistant to weathering and is often found in sedimentary rocks and soils as a result of its durability. Aluminum-rich clay minerals, on the other hand, are typically formed through the weathering and decomposition of other minerals, such as feldspars and micas, which contain aluminum.
Quartz can occur in various forms, including transparent to translucent crystals, as well as cryptocrystalline varieties such as chalcedony, agate, and jasper. It exhibits a wide range of colors, including clear, white, pink, purple, yellow, brown, and black, among others. The color variations in quartz are due to impurities or trace elements present during its formation.
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Somebody please help me with this problem!!
Answers
Explanation:
I guess since it has greater number on ions it won't react as heavily as the others, I'm going based off of atoms.
In general, what causes a sea breeze?
O
A. The difference in density between land and water
B. The difference in cloud cover between land and water
Ο Ο Ο
C. The difference in specific heat capacity between land and water
D. The difference in elevation between land and water
Answers
Answer:
The usual cause of sea breeze is the difference in specific heat capacity between land and water Land heats and cools more quickly than water. What is the cause of a sea breeze? The air over the land is warmed and rises, to a greater temperature than that over the sea.
Explanation:
Your answer is C ! <3
The difference in specific heat capacity between land and water is the cause of sea breeze.
What is sea breeze?land and ocean heat up at different rates, sea breezes often occur during hot, summer days. The land surface warms up more quickly than the water surface during the day. As a result, the air above land is warmer than that over water.
Just to refresh your memory, warmer air is lighter than cooler air. Warm air rises as a result. As a result, the warmer air above the ground is rising. The cooler air above the water is moving across the surface of the land to replace the rising heated air as it rises over the land.
This is the sea breeze, which is seen at the top of the next picture. The land breeze that happens is seen at the bottom of the following picture.
Therefore, The difference in specific heat capacity between land and water is the cause of sea breeze.
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A 17.5 ml sample of an acetic acid (ch3co2h) solution required 29.6 ml of 0.250 m naoh for neutralization. the concentration of acetic acid was __________ m.
Answers
Answer:
0.423M
Explanation:
The reaction of acetic acid with NaOH is:
CH₃CO₂H + NaOH → CH₃CO₂Na + H₂O
That means the moles of NaOH added = Moles acetic acid in the solution
To solve this problem we need to find the moles of NaOH added to find the moles of acetic acid and its concentration using its volume as follows:
Moles NaOH:
29.6mL = 0.0296L * (0.250mol / L)= 0.0074 moles NaOH = Moles acetic acid
Molarity acetic acid:
0.0074 moles / 0.0175L =
0.423Mtrue or false, cross interactions between components of a mixture are represented by the ideal mixture model.
Answers
The statement "Cross interactions between components of a mixture are represented by the ideal mixture model." is False.
The ideal mixture model represents interactions between components of a mixture as zero. According to the ideal mixture model, the energy of a mixture of gases is determined entirely by the kinetic energy of the individual molecules in the mixture.
A binary solution is a mixture of two pure components. An ideal solution is one in which the behavior of each component is ideal, implying that the intermolecular forces between the different molecules are identical, as are the intermolecular forces between the like molecules. In this case, the interactions between the molecules in the solution would be identical to the interactions between the molecules in the pure liquids.
The model that represents cross interactions between components of a mixture is the non-ideal mixture model. Non-ideal mixtures are mixtures in which the intermolecular forces between the components vary from one component to the next.
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glycogen is a polymer of glucose that is held together by bonds. the branch points are held together by bonds.
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Glycogen, a polymer of glucose, is held together by glycosidic bonds, including the bonds at its branch points.
Glycogen is a complex carbohydrate that serves as a storage form of glucose in animals, including humans. It is made up of glucose units linked together through glycosidic bonds. These bonds form between the hydroxyl (OH) group of one glucose molecule and the anomeric carbon (C1) of another glucose molecule, resulting in a linear chain of glucose units.
Additionally, glycogen has branch points where the chain is extended by the formation of α-1,6-glycosidic bonds. These branch points contribute to the highly branched structure of glycogen, allowing for more efficient storage and rapid release of glucose when needed.
Therefore, the bonds that hold glycogen together, both in the linear chain and at the branch points, are glycosidic bonds. These bonds play a crucial role in maintaining the integrity and functionality of glycogen as a storage form of glucose in the body.
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suppose you mix 100.0 g of water at 26.1 oc with 75.0 g of water at 75.4 oc. what will be the final temperature of the mixed water, in oc? type answer:
Answers
The final temperature of the mixed water is \(T=\frac{2.333}{101.5}\).
The combined water's ultimate temperature is 45.6 0C.
the settings provided;
Initial water temperature, \(t_1\), was 26.1C; initial water temperature, \(t_2\), was 75.4C. The mass of the cold water was 100 g.
75 g is the hot water's mass.
Water has a specific heat capacity of 4.184 \(\frac{J}{gC}\).
The mixture's ultimate temperature is estimated as follows;
based on the idea of energy conservation;
Heat received by the cold water equals heat lost by the hot water.
mcΔθ₂ = mcΔθ₁
75 x 4.184 x (75.7 - T) = 100 x 4.184 x (T - 26.1)
75 x (75.4 - T) = 100 x (T - 26.1)
(75.4 - T) = 1.333(T - 26.1)
75.4 - T = 1.333T - 34.719
75.4 + 26.1 = 1.333T + T
101.5 = 2.333T
\(T=\frac{2.333}{101.5}\) which gives the final temperature.
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Which of the following is an example of using creativity while recording measurements during an experiment? (5 points) a Writing a hypothesis b Organizing data in tables c Validating results by repetition d Interpreting results based on data
Answers
Answer:A
Explanation:
Which of the following is a nonelectrolyte?
HCI
Rb2SO4
CH3CH2OH
KOH
NaCl
Answers
Help what is the answer?
Answers
The specific heat of mercury calculated from her data is 0.13 J/g°C.
Specific heat is a measure of how much energy is required to heat a substance. This is the amount of energy (in joules) required to heat 1 gram of a substance by 1°C. Different substances have different specific heats.
To answer this question, use the heat slaughter formula:
Q =mCΔT
In the question:
Heat energy: Q = 30.1 J
Mass of mercury: m = 12.5 g
T1 = 21.2
T2 = 39.6°C
Temperature:
ΔT = T2 –T1
∆T = 39.6 – 21.2
∆T = 18.4°C
The specific heat of mercury is?
Q =mCΔT
C = Q/mΔT
C = 30.1/12.5 x 18.4
C =30.1/230
C = 0.13 J/g°C
So, the specific heat of mercury is 0.13 J/g°C.
Question:
In the laboratory a student finds that it takes 30.1 Joules to increase the temperature of 12.5 grams of liquid mercury from 21.2 to 39.6 degrees Celsius.
The specific heat of mercury calculated from her data is_____J/g°C.
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which structure below represents the arrangement of atoms in pure copper ?.
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a flask contains 2.838 m formic acid and 1.913 m formate anion. these two chemicals are a conjugate acid/base pair that should be able to form a buffer. if formic acid has a 298 k value for ka of 1.85x10-4, what is the ph of the solution in this flask?
Answers
The pH of the buffer solution given in the flask containing 2.838 m formic acid and 1.913 m Formate anion is 3.56.
The pH of a buffer solution can be calculated using the Henderson-Hasselbalch equation:
pH = pKa + log([A⁻]/[HA])
where pKa is the acid dissociation constant of formic acid (HCOOH) which is 1.85x10⁻⁴ at 298 K1, [A⁻] is the concentration of Formate anion (HCOO⁻) and [HA] is the concentration of formic acid (HCOOH).
The molarity of formic acid in the flask is 2.838 M and that of Formate anion is 1.913 M.
Since these two chemicals are a conjugate acid/base pair that should be able to form a buffer, we can assume that all of the formic acid will dissociate into H⁺ and HCOO⁻ ions.
Therefore,
[HCOO⁻] = 1.913 M and
[H⁺] = 1.85x10⁻⁴ × 2.838 / 1.913
= 2.75 x 10⁻⁴ M.
Taking -log[H⁺] gives us pH:
= -log(2.75 x 10⁻⁴) = 3.56.
Therefore, the pH of the solution in this flask is 3.56.
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True or false: the moment of inertia of a hoop that has a mass and a radius is greater than the moment of inertia of a disk that has the same mass and radius.
Answers
It is true that the moment of inertia of a hoop that has a mass and a radius is greater than the moment of inertia of a disk that has the same mass and radius.
Lower moments of inertia signify that only small forces are required to create a rotation, whereas higher moments of inertia mean that greater force must be used. The masses with the largest moment of inertia are those that reside furthest from the axis of rotation.
Due to the fact that a ring's center of mass is located on an axis that is perpendicular to its plane and passes through it, a ring has a higher moment of inertia than that of a circular disc of equal mass and radius. Because all of a ring's mass has been concentrated at the rim, which is furthest from the axis, which has a greater moment of inertia.
Therefore, the given statement is true.
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While coming back from school, Seema noticed some cattle grazing in the field near his school. But one thing fascinated her was the animals were chewing even when they take rest. A. What is this group of animals and process known as? B. Explain the process of digestion in a cow.
Answers
Answer:
Explanation:
These are normal field cows. When they are resting they are not chewing food but are actually chewing their cuds. By doing so they generate saliva which helps them properly digest all of the food that they have eaten and protect their stomach from any harmful chemicals that they may have ingested. A secondary benefit is also that it helps them produce milk more often. This is why you see these cows chewing at all times of the day even when they are not currently eating.
adding 50.0 ml of 0.1 m hcl to a 100.0 ml of 0.2 m nh3 solution could prepare a buffer. true or false?
Answers
The statement "adding 50.0 mL of 0.1 M HCl to a 100.0 mL of 0.2 M NH3 solution could prepare a buffer" is false.
To determine whether adding 50.0 mL of 0.1 M HCl to a 100.0 mL of 0.2 M NH3 solution could prepare a buffer, we need to calculate the pH of the resulting solution after the addition of HCl.
NH3 (aq) + HCl (aq) → NH4Cl (aq)
The balanced chemical equation above shows that HCl reacts with NH3 to form NH4Cl. NH4Cl is an acidic salt, meaning it will increase the acidity (decrease pH) of the solution.
To calculate the pH, we need to first determine the moles of each species present in the solution after the addition of HCl.
Moles of NH3 = (0.2 mol/L) × (0.100 L) = 0.02 mol
Moles of HCl = (0.1 mol/L) × (0.050 L) = 0.005 mol
The moles of NH3 is greater than the moles of HCl, meaning there is excess base in the solution. However, we cannot determine whether or not the solution is a buffer based on this information alone.
To be a buffer, the solution must contain both a weak acid and its conjugate base or a weak base and its conjugate acid. In this case, NH3 is a weak base and NH4+ is its conjugate acid.
Therefore, in order to prepare a buffer, we need to add NH4Cl to the solution to provide the conjugate acid to NH3. If we only add HCl to NH3, the resulting solution will not be a buffer.
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1 Which of the following is true about a compound and its elements? A. The compound shares identical properties with one element, but all the other elements have different properties. B. The properties of a compound are different than the properties of its elements. C. The properties of a compound are the same as the properties of its elements. D. The elements all share identical properties, but their properties are different than the compound's properties.
Answers
Although the elements' properties are the same for all of them, they are distinct from those of the compound.
What type of attribute is a compound?A property with several buildings in one location is referred to as a real estate compound. Even while many of them serve as playgrounds for such famous and wealthy, they serve other functions as well.
Do various chemicals have distinct properties?Chemical characteristics of a compound are distinct from those of the elements its includes. When two or even more atoms get chemically linked, a material called a molecule is created (bonded).
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Which of the following strategies will best help you control your risk of developing CVD?
- Consuming high amounts of refined carbohydrates
- Smoking to prevent weight gain
- Using margarine rather than olive oil
- Drinking three glasses of red wine every day
- Substituting fish for red meat twice a week
Answers
The strategy that best helps control the risk of developing cardiovascular disease (CVD) is - Substituting fish for red meat twice a week.
This choice is beneficial for several reasons:
1. Omega-3 Fatty Acids: Fish, such as salmon, trout, and mackerel, are rich sources of omega-3 fatty acids. These healthy fats have been shown to have protective effects on the cardiovascular system, reducing the risk of heart disease and stroke.
2. Reduced Saturated Fat: Red meat is often higher in saturated fat compared to fish. Consuming high amounts of saturated fat is associated with an increased risk of CVD. By substituting fish for red meat twice a week, you can lower your overall intake of saturated fat.
It's worth noting that managing the risk of CVD involves adopting a comprehensive approach rather than relying on a single strategy.
Other important factors include maintaining a balanced and healthy diet overall, engaging in regular physical activity, avoiding smoking, managing stress levels, and maintaining a healthy weight.
However, it's essential to consult with a healthcare professional or a registered dietitian for personalized advice on managing your specific risk factors for cardiovascular disease.
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What type of solution are solution A and solution C?
Answers
Calculate the number of miles in 20g of neon
Answers
The number of moles in 20g of Ne is 1 mole.
What is a mole?
The mole is an amount unit similar to familiar units like pair, dozen, gross, etc. It provides a specific measure of the number of atoms or molecules in a bulk sample of matter.
A mole is defined as the amount of substance containing the same number of atoms, molecules, ions, etc. as the number of atoms in a sample of pure 12C weighing exactly 12 g.
Given,
Mass of Ne = 20g
Molar mass of Ne = 20 g/mole
Moles = mass ÷ molar mass
= 20 ÷ 20
= 1 mole
Therefore, the number of moles in 20g of Ne is 1 mole.
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The question has spelling mistake. Probably the question is:
Calculate the number of moles in 20g of neon.
Which of the following quantities are required for calculating density? Select all that required.
Volume
Area
Mass
Weight
Answers
Answer:
Mass and Volume
Explanation:
The formula for density is
\(\frac{Mass}{Volume}\)
Use the equation to answer the question.
H2O(l) + heat = H2O(g)
A sample of water is at equilibrium at 100°C. Which statement best describes what will happen if liquid water is added to the system?
A) All of the liquid water molecules that are added will remain
liquid water.
B) More water vapor molecules will change to liquid water until a
new equilibrium is reached.
C) All of the liquid water molecules that are added will become
water vapor.
D) More liquid water molecules will change to water vapor until a
new equilibrium is reached.
Answers
Answer:
D
Explanation:
More liquid water molecules will change to water vapor until a
new equilibrium is reached.
Answer:
Equilibrium and Stability Quick Check
1. The rate of the forward reaction equals the rate of the reverse reaction.
2. More LIQUID WATER molecules will change to WATER VAPOR until a new equilibrium is reached.
3. By adding WATER (H2O).
4. The additional BROMINE IONS cause the equilibrium to shift to the REACTANTS.
5. Removing WATER (H2O).
Explanation:
100% if you put these answers.