Fossils are the preserved remaining, impressions or traces of prehistoric organisms.
Trace fossils are the naturally preserved evidence of animal activity like footprints of animals.
Body fossils are formed from the remaining of dead animals and plants like bones, teeth etc.
Bone fossils are the remaining of bones.
Cast fossils are formed by hardening of mud or sand that is filled in the mold and thus gives the shape of the organism
Thus, option D that is cast fossils record the shape and structures of an organism.
How can a permanent magnet make the light bulb glow
A permanent magnet can make a light bulb glow by making it move as to convert kinetic and magnetic energy into electric current. Both energy combined in a coil of copper wire causes the electrons in the wire to move then create an electric current and make the light bulb glow.
Moreover, this process is called electromagnetic induction where there is a creation of potential difference or voltage through an electric conductor, such as coil of wire, when it is exposed to a varying or moving magnetic field. As long as the conductor is part of a closed circuit, current will flow through it whenever it crosses lines of force in the magnetic field. The faster the magnet or coil moves, the greater the amount of electric current is produced. If more turns were added to the coil or a stronger magnet were used, this would produce more current too.
When sugar and iron filings are mixed together, you can separate them using a magnet. When sugar and iron filings are mixed and then heated until a chemical reaction occurs, you can A) still separate the iron filings with a magnet. B) no longer separate the iron filings with a magnet. C) sift the mixture to separate out the sugar from the iron. D) dissolve the sugar in water to separate it from the iron.
Answer:
The answer is D. dissolve the sugar in water to separate it from the iron.
Explanation:
hope this helps :)
The component from a mixture can be separated using some methods based on the individual properties.The heating iron and sugar will lead a chemical change and they cannot be separated then using a magnet or by dissolving in water.Thus option B is correct.
What is magnetic separation?Some components which are magnetically susceptible can be separated from a mixture . Especially materials containing iron can be separated using a magnet.
During a chemical change, chemical bonds will break and form new products. Heating will make a material undergo some chemical changes. When iron and sugar are heated they both melt if higher temperature is applied.
Iron forms compound with sugar molecules, thus it cannot be separated using a magnet after heating. Both iron and sugar are soluble in water. Therefore, separation by dissolving in water is possible here. Hence option B is correct
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how many moles of sodium are needed to react with sulfuric acid to produce 3.75 moles of sodium sulfate according to the following unbalanced reaction :
What is the most stable condition for an atom
In a chromatography experiment, chlorophyll pigments are separated using paper. What is the stationary phase in this experiment?
Answer:
Chromatography paper.
Explanation:
Chromatography may be defined as the technique used for the separation of molecules on the basis of their size, shape and color. The chromatography requires the mobile phase as well as the stationary phase.
The different pigments of chlorophyll can be separated by the chromatography technique. Here, the chromatography paper work as stationary phase and the drop of cholorophyll is placed on the paper. The water is used as mobile phase and as it moves over the paper separates the component of cholorophyll.
Thus, the answer is chromatography paper.
Blank is anything that has mass and volume.
Final answer:
Matter is anything that occupies space and has mass. Solids, liquids, and gases are all forms of matter. Mass is a measure of the amount of material within an object, while volume is the measure of the physical space it occupies.
Explanation:
Matter is defined as anything that occupies space and has mass. Solids and liquids are more obviously matter: We can see that they take up space, and their weight tells us that they have mass. Gases are also matter; if gases did not take up space, a balloon would not inflate (increase its volume) when filled with gas.
Mass is a measure of the amount of material within an object. The quantity or amount of matter in an object is determined by the numbers of atoms and molecules of various types it contains.
The volume of an object is the measure of the physical space it occupies. Volume is measured in cubic units, such as cubic centimeters or liters. The volume is the "size" of an object.
Calculate the molarity of 90.0 mL of a solution that is 0.92 % by mass NaCl. Assume the density of the solution is the same as pure water.
Final answer:
To calculate the molarity of a 0.92% NaCl solution with a volume of 90.0 mL, convert the mass percentage to grams, turn grams to moles using the molar mass of NaCl, and divide by the volume in liters to find the molarity, which is 0.158 M.
Explanation:
The question asks to calculate the molarity of a 0.92% by mass NaCl solution with a volume of 90.0 mL and assuming the density is that of pure water. To solve this, we perform the following steps:
Calculate the mass of NaCl in 90.0 mL of the solution using the percentage by mass. Since the density of water is approximately 1 g/mL, 90.0 mL of the solution also has a mass of 90.0 g. Therefore, the mass of NaCl in the solution would be 0.92% of 90.0 g, which equals 0.828 g.Convert the mass of NaCl to moles using NaCl's molar mass. The formula mass of NaCl is 58.44 g/mol. Thus, the number of moles of NaCl is 0.828 g / 58.44 g/mol = 0.0142 moles.Convert the volume of the solution to liters, as molarity is defined as moles per liter. Here, 90.0 mL = 0.090 L.Finally, calculate the molarity by dividing the moles of NaCl by the volume of the solution in liters. Molarity = 0.0142 moles / 0.090 L = 0.158 M (molar).Final answer:
To find the molarity of a 90.0 mL NaCl solution that is 0.92% by mass, convert the mass of NaCl to moles using its molar mass, and then divide by the volume in liters. The molarity of the solution is 0.158 M.
Explanation:
To calculate the molarity of a 90.0 mL NaCl solution that is 0.92% by mass, we first need to determine the mass of NaCl in the solution. Since the solution is similar in density to water, we can assume it is 1 g/mL.
This means that 90.0 mL of the solution has a mass of 90.0 g. To find the mass of NaCl:
Mass of NaCl = 0.92% of 90.0 g = 0.0092 × 90.0 g = 0.828 g
Next, we convert the mass of NaCl to moles:
Moles of NaCl = Mass of NaCl / Molar mass of NaCl
Moles of NaCl = 0.828 g / 58.44 g/mol = 0.0142 mol
Finally, we convert from grams to moles to find the molarity:
Molarity (M) = Moles of NaCl / Volume of solution in liters
Molarity (M) = 0.0142 mol / 0.090 L = 0.158 M
KCl(aq) + AgF(aq) → AgCl(s) + KF(aq)
If 0.25 moles of potassium chloride are consumed completely, how many moles of potassium fluoride will be produced?
A)
1.0 mole
B)
0.25 moles
Eliminate
C)
0.50 moles
D)
There is no way to tell because we do not have enough information
It is the same answer as in the question so the answer is b
Based on the law of conservation of energy, which statement is false?
what changes could be made to optimize the manufacturing process
Mr X was accused of speeding along a highway. He was travelling at different speeds,but an average speed of 80 km/h. Based on thr given information, is Mr X gulity or innocent?
If Kp = 0.15, which statement is true of the reaction mixture before any reaction occurs?
How does a nuclear power plant produce electricity?
A. Quickly moving neutrons coming out of the reaction create a gas which turns a turbine that produces electricity.
B. Quickly moving neutrons coming out of the reaction are slowed down by water. The water heats up and turns into steam. The steam turns the turbine and produces electricity.
C. Quickly moving neutrons coming out of nuclear reactions are used to turn turbines that produce electricity.
D. Quickly moving neutrons give their kinetic energy to the surrounding water. The water's energy is then used to turn turbines and produce electricity.
The Answer Is B.Quickly moving neutrons coming out of the reaction are slowed down by water. The water heats up and turns into steam. The steam turns the turbine and produces electricity.
How many hydrogen atoms are there in 5 molecules of CH2Cl2?
The 1 molecule of CH₂Cl₂ contains 2 hydrogen atoms so for 5 molecules of CH₂Cl₂ there will be 10 hydrogen atoms.
What are molecules?Molecules are defined as a group of two or more atoms that forms a smallest identifiable unit into which pure substance can be divided and still retain the composition and properties of that substance.
It can also be defined as two or more atoms connected by a chemical bonds.
Atoms can be defined as a smallest unit of ordinary matter that forms a chemical elements.
Thus, the 1 molecule of CH₂Cl₂ contains 2 hydrogen atoms so for 5 molecules of CH₂Cl₂ there will be 10 hydrogen atoms.
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What most likely happens when water vapor cools? A. It changes into gas. B. It changes into liquid. C. Its temperature increases. D. Its temperature remains constant.
Answer: Option (B) is the correct answer.
Explanation:
When water converts from vapor form to liquid form then this process is known as condensation.
Water vapors are the gaseous form of water, that is, its molecules are weakly held by Vander waal forces.
When temperature is decreased then water vapor converts into liquid form.
Thus, we can conclude that when water vapor cools then most likely it changes into liquid.
According to the forces of attraction, when vapor cools it changes to liquid thus option B is correct.
Forces of attraction is a force by which atoms in a molecule combine. it is basically an attractive force in nature. It can act between an ion and an atom as well.It varies for different states of matter that is solids, liquids and gases.
The forces of attraction are maximum in solids as the molecules present in solid are tightly held while it is minimum in gases as the molecules are far apart . The forces of attraction in liquids is intermediate of solids and gases.
The physical properties such as melting point, boiling point, density are all dependent on forces of attraction which exists in the substances.
Thus, when vapor cools it changes to liquid thus option B is correct.
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Number of miles of Xe in 12.00g of Xe
To find the number of moles of xenon in a 12.00g sample, divide the mass by the molar mass of Xe, approximately 131.29 g/mol.
This is a basic chemistry problem involving the use of the molar mass of an element to convert from grams to moles.
To find the number of moles, we use the molar mass of xenon, which can be found on the periodic table. Xenon's molar mass is approximately 131.29 g/mol. Therefore, to convert grams to moles, we take the mass of the sample and divide it by the molar mass of the substance:
Number of moles of Xe = Mass of the sample (in grams) / Molar mass of Xe (in grams per mole)For a 12.00g sample of xenon, the calculation would be:
Number of moles of Xe = 12.00g / 131.29g/molCorrect scientific term for a substance that is burned to provide heat?
Gamma rays are often used to kill microorganisms in food, in an attempt to make the food safer. Some people contend that this irradiated food is actually less safe to eat. Which, if true, would most effectively dispute their idea?
Irradiated food is shown to not be radioactive, which directly dispels safety concerns. Gamma irradiation safely extends food shelf life by eliminating harmful microbes and is regulated by the FDA to ensure safety. Option B is correct.
The best choice that would contradict the safety concerns about irradiated food is Irradiated food is shown to not be radioactive. This directly addresses the main public concern that consuming irradiated food could lead to exposure to radioactivity.
Gamma irradiation is used as a method to eliminate harmful microbes in food, thereby extending its shelf life and making it safer. The foods subjected to irradiation do not become radioactive themselves because the irradiation process does not involve direct contact with radioactive materials. Furthermore, the Food and Drug Administration (FDA) regulates the sources of radiation and has determined that irradiating food is a safe practice.
Thus, contradicting the misconception, irradiated food retains its nutritional quality and is considered safe for consumption.
Hence, B. is the correct option.
The complete question is:
Gamma rays are often used to kill microorganisms in food, in an attempt to make the food safer. Some people contend that this irradiated food is actually less safe to eat. Which, if true, would most effectively dispute their idea?
A) Irradiated food only emits alpha particles, which are harmless.
B) Irradiated food is shown to not be radioactive.
C) Irradiated food only contributes to background radiation.
D) Irradiated food has molecules that undergo transmutation
A 1 kg block of copper is hammered into a thin sheet. The length of the copper sheet is 30 cm. What is the mass of the copper sheet? A) 1 kg B) 30 kg C) 1.03 kg D) Cannot be calculated at all
The mass of copper will remain the same. Therefore, the mass of the copper is equal to 1 Kg. Therefore, option A is correct.
What is law of conservation of matter?Matter can be transformed form through physical changes and chemical changes from one form to another form, but through all changes, the matter will remain conserved. The same quantity of matter will be there even before and after the change therefore none of the matter is created or destroyed.
According to this law, that mass is never formed nor destroyed, although it may be rearranged in space with the changes associated with it may be changed its form.
For example, the mass of the chemical components before the reaction in chemical reactions is equal to the mass of the components after the reaction.
On hammering the copper mass into the tin sheet, the shape of the copper mass will change but the mass of the metal will remain the same. Therefore, the mass of the copper is equal to 1 Kg.
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Final answer:
The mass of the copper sheet after it has been hammered remains 1 kg, as the mass of an object does not change due to changes in shape or size (option A).
Explanation:
The mass of the copper sheet after it has been hammered into a thin sheet remains the same, regardless of its shape or size alterations. The fundamental principle here is the conservation of mass, implying that the mass of an object doesn't change unless material is added to or removed from it. No such addition or removal of material is mentioned in the question.
Therefore, even after the transformation of the 1 kg block of copper into a copper sheet of length 30 cm, the mass of the copper sheet will be 1 kg, corresponding to option A. This is because the question states that it is the same block of copper that has been reformed, so no mass has been lost or gained in the process.
The world's population:
is unequally distributed
lives primarily in agricultural areas
decreases slightly each year
all of the above
Answer:
is unequally distributed
Explanation:
because my finals say so
Four friends were talking about how matter and energy move through an ecosystem. This is what they said:
Will - "I think only energy cycles through an ecosystem."
Mike - "I think only matter cycles through an ecosystem."
Dustin - "I think both matter and energy cycle through an ecosystem."
Lucas - "I think neither matter nor energy cycles through an ecosystem."
Which friend do you most agree with? EXPLAIN your thinking.
Final answer:
Dustin's statement that both matter and energy cycle through an ecosystem is the most accurate, as energy flows through an ecosystem and is lost as heat, while matter is recirculated via biogeochemical cycles.
Explanation:
Among the statements made by the four friends regarding how matter and energy move through an ecosystem, Dustin's statement aligns most closely with scientific understanding. Energy enters an ecosystem from external sources, primarily the sun, and flows through the ecosystem from producers to consumers in a one-way path, ultimately being lost as heat. Unlike energy, matter, such as water, carbon, and nitrogen, is recycled within the ecosystem through biogeochemical cycles. These cycles involve both living organisms and non-living matter, ensuring that matter is continually used and reused within the ecosystem.
Chemical and physical properties are used to help identify substances. A substance's chemical properties identify whether or not that substance reacts with another substance. What chemical property is present in substances that react slowly to oxygen?
Chemical and physical properties are used to help identify substances. A substance's chemical properties identify whether or not that substance reacts with another substance or it can be said that a chemical property of a substance will helps in deciding whether the substance will react or not with another substance. To react with oxygen, the substance should have the ability to burn, the more quickly the substance burn, more readily the substance will burn to produce light and heat.
This can also be explained with the formation of rust on a chemical compound, The more readily the compound reacts with oxygen, more readily it undergoes rusting .
For example when iron kept in open air, it undergoes rust as it reacts with oxygen.
Which statement accurately describes what happens when water turns to stream in terms of energy?
A. The water releases energy which causes chemical bonds to break, changing water to steam.
B. The water releases energy which causes the water molecules to have less kinetic and potential energy, changing their configuration from liquid to gas.
C. The water absorbs energy which causes chemical bonds to break, changing water to steam.
D. The water absorbs energy which causes the water molecules to have more kinetic and potential energy, changing their configuration from a liquid to a gas.
C. The water absorbs energy which causes the water molecules to have more kinetic and potential energy, changing their configuration from a liquid to a gas.
I took the quiz and this is the correct answer
The actual yield of a certain reaction is 34.0 g, while the theoretical yield is 50.0 g. Calculate the percent yield.
At area 1, a stream empties into the ocean. At area 2, precipitation enters the ocean in the form of rainfall. At area 3, evaporation takes place at the ocean’s surface. In which areas does the salinity of the ocean decrease?
Answer:
1 and 2
Explanation:
i just took the exam on plato, plus its common sense and it cannot be 3 because it has nothing to do with it.
The salinity of the ocean decreases at area 1, where a stream flows into it, and at area 2, where rainfall adds freshwater. Evaporation at area 3 increases salinity as only water is removed, not the salts.
The areas where the salinity of the ocean decreases are areas where freshwater is added to the ocean. At area 1, where a stream empties into the ocean, freshwater from the stream mixes with saltwater, diluting the salinity. Similarly, at area 2, when precipitation such as rain enters the ocean, it also lowers the salinity because rainwater has lower salt content compared to ocean water. On the other hand, at area 3, where evaporation occurs, water is removed from the ocean leaving the salts behind, which actually increases the ocean's salinity.
Salinity is a key component of the water cycle and the ocean's composition. The saltwater in the oceans is highly saline, with about 35,000 mg of dissolved ions per liter. When freshwater, which has lower salinity, enters the ocean, it causes a decrease in the overall salinity of the ocean at the point of entry. In contrast, evaporation of ocean water leaves the salts behind, resulting in increased salinity.
How many atoms of oxygen are in 8.43 g of magnesium sulfate heptahydrate (Epsom salts)?How many atoms of oxygen are in 8.43 g of magnesium sulfate heptahydrate (Epsom salts)?
Answer: The number of oxygen atoms in given amount of magnesium sulfate heptahydrate is [tex]2.265\times 10^{23}[/tex]
Explanation:
To calculate the number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
Given mass of magnesium sulfate heptahydrate = 8.43 g
Molar mass of magnesium sulfate heptahydrate = 246.47 g/mol
Putting values in above equation, we get:
[tex]\text{Moles of magnesium sulfate heptahydrate}=\frac{8.43g}{246.47g/mol}=0.0342mol[/tex]
The chemical formula of magnesium sulfate heptahydrate is [tex]MgSO_4.7H_2O[/tex]
1 mole of magnesium sulfate heptahydrate contains 1 mole of magnesium atoms, 1 mole of sulfur atoms, 11 moles of oxygen atoms and 14 moles of hydrogen atoms
According to mole concept:
1 mole of a compound contains [tex]6.022\times 10^{23}[/tex] number of particles
So, 0.0342 moles of magnesium sulfate heptahydrate will contain = [tex](11\times 0.0342\times 6.022\times 10^{23})=2.265\times 10^{23}[/tex] number of oxygen atoms
Hence, the number of oxygen atoms in given amount of magnesium sulfate heptahydrate is [tex]2.265\times 10^{23}[/tex]
which feature form the longest-mountain range on Earth?
The law of universal gravitation states that any two objects in the universe, without exception, a. attract each other. b. repel each other. c. combine to provide a balanced force. d. create friction. im not sure help
What is similar between Gregor's life before and after his physical transformation?
A. He still supports his family financially
B. He is still happy that he has a nice famiky who lives him.
C. He still feels bored and unsatisfied with his life.
D. He is still excited to see what will happen each day.
The similarity between Gregor's life before and after his physical transformation is that,
He is still happy that he has a nice family who lives him.What is physical transformation and how changes occur?The changes occur only by physically is called physical transformation.The changes occurs are,
Reactions SkinHeightWeightsexual organbrainTeeth etc.learn about physical transformation,
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2 molecules of Acetaldehyde can only be made from which of these alkenes?