Answer: He thought that all materials on Earth were not made of atoms, but of the four elements, Earth, Fire, Water, and Air.
Explanation: Aristotle did not believe in the atomic theory and he taught so otherwise. He thought that all materials on Earth were not made of atoms, but of the four elements, Earth, Fire, Water, and Air. He believed all substances were made of small amounts of these four elements of matter.
Does neon have more valence electrons than oxygen?
biography of the person who discovered o2
Answer:
Oxygen was discovered independently by two chemists in the late 18th century: Carl Wilhelm Scheele and Joseph Priestley.
Carl Wilhelm Scheele was a Swedish chemist who is credited with the discovery of several elements, including oxygen, chlorine, and molybdenum. He was born on December 9, 1742, in Stralsund, Sweden, and showed an early interest in chemistry. In the 1770s, he made several important discoveries related to oxygen, including the fact that it is a gas and that it is necessary for combustion. However, he did not publish his findings until after Priestley had published his own work on oxygen. Scheele died on May 21, 1786, at the age of 43.
Joseph Priestley was an English scientist, philosopher, and theologian who is best known for his discovery of oxygen. He was born on March 13, 1733, in Birstall, England, and studied theology and science at the University of Leeds. In the 1770s, he conducted a series of experiments in which he isolated and described oxygen. He published his findings in 1774, in a book called "Experiments and Observations on Different Kinds of Air." Priestley's work on oxygen helped to lay the foundations for modern chemistry and the understanding of combustion and respiration. He died on February 6, 1804, at the age of 70.
Is NaCl ionic or covalent?
Answer:
ionic
Explanation:
compounds that are ionic are formed as a result pf a transferring of electrons that creates ions; which exert an electrostatic force upon each other.
What is the orbital hybridization of C?
When a carbon atom bonds with one s-orbital and two p orbitals, it becomes sp2 hybridised. Between the three atoms, two single bonds and one double bond are formed. The hybrid orbitals are arranged in a triangle with bonds at 120° angles.
What is Hybridization of carbon ?Four sp3 orbitals are created when the 2s and all three of the 2p orbitals of carbon combine. Through an overlap of the sp3 and s orbitals, these orbitals subsequently form a link with four hydrogen atoms to form methane.
Carbon consists of six electrons. In the 1s orbital, just outside the nucleus, there will be two of them. The following two will enter the orbital phase 2s. The rest will be split into two distinct 2p orbitals.
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Indicate the oxidation number of carbon and sulfur the in following compounds.Procedurea. CO b. CO2 c. Na2CO3d. Na2C2O4 e. CH4 f. H2COg. SO2 h. SO3 i. Na2SO4j. Na2SO3 k. Na2S2O3 l. Na2S4O6m. SCl2 n. Na2S2 o. SOCl2
Oxidation number of C is a) +2 b) +4 c) +4 d) +3 e) -4 f) 0 g) +4 h) +6 i)+6
j) +4 k) +2 l)2.5 m) -2 n) -1 o) +4
A) CO
x + (-2) = 0
Thus, x = +2
Oxidation number of C = +2
B) CO2
x + 2 (-2) = 0
x = +4
Oxidation number of C = +4
C) Na2CO3
2 (+1) + x + 3(-2) =0
2 + x -6 = 0
x = +4
Oxidation number of C = +4
D) Na2C2O4
2(+1) + 2x + 4(-2)
2x = +
x = +3
Oxidation number of C = +3
E) CH4
x + 4(+1) = -4
Oxidation number of C = -4
F) H2CO
2(+1) + x (-2) =0
x = 0
Oxidation number of C = 0
G) SO2
x + 2 (-2) = 0
x = +4
H) SO3
x + 3(-2) = 0
x = +6
I) Na2SO4
2(+1) + x + 2(--4)
x = +6
K) Na2SO3
2(+1) + x + 3(-2) =0
2 + x -6 = 0
x =+4
K) Na2S2O3
2(+1) + 2x + 3(-2) =0
2x = +4
x = +2
L) Na2S4O6
2(+1) + 4 x + 6(-2) =0
4x = 10
x = 2.5
M)SCl2
x + 2(-1) = 0
x = -2
N) Na2S2
2(+1) + 2x = 0
x = -1
O) SOCl2
x + -2 + 2(-1)
X = +4
An atom's hypothetical charge, or oxidation number, would be zero if all of its links to other atoms were completely ionic. It describes how much an atom in a chemical compound has oxidised (lost electrons). The oxidation state could theoretically be zero, positive, or negative. Owing to the fact that many bonds in nature exhibit high ionicity despite the absence of fully ionic bonds, the oxidation state is a good indicator of charge.
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CuS + AgNO3(aq) > Cu(NO3)2(aq) + Ag(s) balanced
Answer:
CuS + 2AgNO3(aq) > Cu(NO3)2(aq) + Ag2S
Explanation:
The reaction is CuS + AgNO3(aq) > Cu(NO3)2(aq) + Ag2S
so the balanced reaction is CuS + 2AgNO3(aq) > Cu(NO3)2(aq) + Ag2S
Cu = 1
S = 1
Ag = 2
NO3 = 2
in an ionic or covalent substance, electrons are shared or transferred between no more than two atoms at a time. however, in a metallic substance, electrons are shared among all of the metal atoms in the sample. how does this explain why metals are more malleable and ductile than ionic and covalent compounds?
Since the electrons in metals are shared across all of the metal atoms in the sample as "sea of electrons" which surrounds the metal ions, making metals more malleable and ductile than ionic and covalent substance.
A metallic composition of all metal atoms surrounds the metal ions with a "sea" of shared electrons. It is assumed that this electron sea is the source of the great conductivity, malleability, and ductility that make metals unique.
Metal ions can easily pass by one another and twist the metal without breaking it because of the electron sea in a metallic body. On the other hand, it is more challenging to modify ionic and covalent molecules without rupturing the bonds due to the strong chemical bonds that hold them together. Because of this, ionic and covalent compounds are less ductile and malleable than metals.
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Balance the following equations to fulfill the law of conservation mass.
C6H12O6+ 6O2+6H2O =
C + ___ S8 ___ CS2
___ Na + ___ O2 ___ Na2O
___ C6H6 + ___ O2 ___ CO2 + ___ H2O
The solution to the preceding equation is: 6C6H6 + 6O2 + 6CO2 + 6H2O = 7C6H12O6 + 3O2 + -18H2O
Negative coefficients indicate that the matching chemicals should be placed on the reaction's opposing side.
Water, Dioxygen, and Glucose are equal to Benzene, Dioxygen, Carbon Dioxide, and Water.
Response Type
Combustion
Redox (Oxidation-Reduction) (Oxidation-Reduction) It's possible that the reaction C6H12O6 + O2 + H2O = C6H6 + O2 + CO2 + H2O is a redox one.
C6H12O6 Glucose, O2 Dioxygen
H2O, or water
C6H6 Benzene
CO2, or carbon dioxide
A simple sugar called glucose is a key source of energy for living things and is found in many different types of carbohydrates.
Combustion: A fuel and an oxidant, often atmospheric oxygen, engage in a high-temperature exothermic (heat-releasing) redox (oxygen-adding) chemical process that results in the production of oxidized, frequently gaseous products in a mixture known as smoke.
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[URGENT!] - Equilibrium Problem
Consider the following reaction:
4A + 2B ⇌ 2C + D (all gases at STP)
Initially, the reaction system is at equilibrium, with [A] = [B] = 2.60 M, and [C] = [D] = 3.10 M, making K = 0.0964. The reaction takes place in a 5.00-liter container. Moles of B are removed until the new equilibrium concentration of C is 2.70. How many moles of B were removed?
The equilibrium constant expression for this reaction is:
K = [C]2[D] / [A]4[B]2
We can rearrange this expression to solve for [B]:
[B] = √([A]4[C]2[D] / K)
Plugging in the given values, we get:
[B] = √((2.60 M)4(2.70 M)2(3.10 M) / 0.0964)
= √(6.76 M)
= 0.26 M
The initial concentration of B is 2.60 M, so the change in concentration of B is 2.60 M - 0.26 M = 2.34 M.
Since the reaction takes place in a 5.00-liter container, the number of moles of B that were removed is 2.34 M * 5.00 L = 11.7 moles.
Therefore, 11.7 moles of B were removed.
Consider the pictured representations of electromagnetic waves. Which electromagnetic wave corresponds to each description? Lowest frequency Choose... Second Highest energy Choose... Highest energy Choose. Shortest wavelength Choose...
In the picture representation of electromagnetic waves,
a) Lowest frequency - C
b) Second Highest energy - A
c) Highest energy - B
d) Shortest wavelength - B
Wavelength can be defined as the distance between identical points (adjacent crests) in the adjacent cycles of a waveform signal propagated in space or along a wire. In wireless systems, this length is usually mentioned in meters (m), centimeters (cm), or millimeters (mm).
If the wavelength of electromagnetic waves is low, the frequency of a wave is also low and the energy is low.
If the wavelength of electromagnetic waves is short, the frequency of a wave is also high and the energy is high.
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Drawbacks include noise and the release of corrosive chemicals.
Geothermal energy is the use of earth heat to produce electrical energy through geothermal power plants. With the corrosive chemicals of geothermal energy come some drawbacks.
The contamination of the air is one such issue. Heavy metals like sulphur, radon salts, and harmful gases that harm the ecosystem are brought up by steam from the earth. Hazardous sludge is created throughout the energy generation process, contaminating the soil and water. Heavy metals present cause pipes to corrode. Construction of geothermal facilities must be done with the utmost care to minimise influence on the local environment. In the first possibility, the chemical's hue is a physical characteristic of a substance. In the presence or absence of a specific chemical, a substance's hue serves as physical identification. Consider sulphur .
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What is the purpose of the absorption and radiation by land and water lab?
The purpose of the absorption and radiation by land and water lab is to analyze the earth's surface.
The Land and Water Absorption and Emission Laboratory evaluate how different surface materials on Earth absorb heat, and how the angle of separation affects how the planet's surface heats up. Designed to show you what to do. It took me about an hour to complete the lab. Earth's surface absorbs much more solar radiation than water. This is because most land surfaces are darker than water. This of course means that it absorbs more solar radiation and heat. Water reflects most of the solar radiation that reaches its surface back to the atmosphere. , the portion of the Earth's surface covered in ice and snow that affects how much of the Sun's solar radiation is absorbed, warmed or reflected by the planet.
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How many electrons fit in p orbital?
Which Of The Following Is Not True?Which Of The Following Statements Is True?
The claim that over-the-counter medications require a doctor's prescription is referred to as being untrue.
What Does Medicine Mean?
This is also known as a medicine, and people use it to diagnose and treat illnesses and other forms of medical ailments. Antimalarials, antibiotics, and other examples all have particular uses and modes of action.
It is untrue that all over-the-counter (OTC) medications require a doctor's prescription because some OTC medications can be purchased without a doctor's prescription. These medications are referred to as OTC medications. Some analgesics and first aid supplies used immediately or during emergencies are medications that don't require a prescription.
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Answer:
If you're on plato edmentum this is the answer, if not then it's not.
Post Test: Government
Economics
Question #6
This answer is 100% correct:
Economic stability means fair distribution of goods in an economy.Full employment is a macroeconomic goal.Inflation is a fall in the prices of goods and services.Inflation is a rise in the prices of goods and services. Microeconomics studies the economy as a whole.
Explanation:
I took the test and this is 100% it
Hope this helped!
What is toxic chemical exposure?
Chronic exposure is prolonged, continuous, or recurrent contact with a harmful chemical (months or years).
Meaning of the term multitudesThe term "masses" designates a sizable, all-inclusive group of commoners — members of a society's middle class.If you're extremely wealthy, you'll go in a private plane while the average person takes a crowded bus.The mass don't include royalty, rich people, famous individuals, or anyone in positions of power.The masses consist of everyone else.
The three masses are what?The three Christmas Masses—at midnight, dawn, and during the day—have a murky history, similar to many liturgical customs.Christmas as just a liturgical holiday celebrated on December 25 first appeared in Rome, somewhere about the year 330.
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Is pewter toxic to humans?
What creates a na concentration gradient in the proximal convoluted tubule?
That creates a Na concentration gradient in the proximal convoluted tubule is Na⁺ / K⁺ pump.
The proximal convoluted tubule is the site of the reabsorption of the electrolytes , the electrolytes examples are sodium , potassium, calcium and the chloride. the proximal tubule is the one of the major element of the kidney and is responsible for the reabsorption. That creates a Na concentration gradient in the proximal convoluted tubule is Na⁺ / K⁺ pump.
The Na⁺ / K⁺ pump is the sodium potassium pump is the active transport. The sodium / potassium pump helps to maintains the higher concentration of the sodium ( Na ) extracellularly and potassium level of intracellularly.
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A gas is heated from 263k to 298k. The volume is increased from 24. 0l to 35. 0l. If the original pressure was 1. 00 atm, what is the new pressure?.
based on the concept of periodic trends, answer the following questions for these atoms: li, be, mg, na. be able to defend your answers. a. which element has the lowest electronegativity? b. which element has the least metallic character? c. which element is the largest atom?
Be has the lowest electronegativity. This is because electronegativity generally increases as you move down a group and to the right of a period, and Be is located at the top left of the periodic table.
Which element has the least metallic character?Li has the least metallic character. This is because metallic character generally decreases as you move down a group and to the right of a period, and Li is located at the top left of the periodic table.
Which element is the largest atom?Mg has the largest atom. This is because atomic radius generally increases as you move down a group and to the left of a period, and Mg is located in the middle of the second period.
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Assume that a hydrogen atom's electron has been excited to the n = 8 level. How many wavelengths of light can be emitted as this excited atom loses energy?
Here is an example
Explanation:
From n = 5 , the electron can drop to n =
4, 3, 2, 1. Thus, there will be 4
possibilities
Now, the electron that dropped to n = 4 can drop to n =3,2,1 This will give 3 possibilities
The electron at n = 3 can drop to n =2,1 This gives 2 possibilities
Finally, the electron at n = 2 can drop to n = 1 . This gives 1 possibility
Thus in total the number of ways in which the electron can de-excite is :
4 + 3 + 2 + 1 = 10
10 different wavelengths of light can be emitted as the electron loses energy
from n = 5 level
divide the compounds below into electron-poor and electron-rich groups.
The electron-poor groups are the ones that make up the majority of the electrons in the material.
This is why it is critical that you divide compounds by the number of electrons they contain. In other words, if you have a compound with two electrons, you want to look at the two-electron group, not the three-electron group. So, if you have a compound with two electrons, you should look at where the two electrons are rather than where they were. Start with the group containing the two electrons and work your way down. Essentially, we want to divide compounds into three groups, three electron groups. The first group has a low electron density, the second has a high electron density, and the third has no electrons. The first group is the easiest to distinguish, but you can see that the first group contains the most electron-rich compounds. The second group is more difficult to distinguish. Because the compounds in the group will have two electrons, it is electron rich. The third group is the most difficult to enter, and it's clear that the second group contains the most electron-free compounds.
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How many moles of MgO is formed?
The moles of MgO produced in the reaction of magnesium and oxygen are 2 moles.
Magnesium oxide is created during the burning of magnesium metal when it combines with airborne oxygen. A compound is a substance made up of atoms from various elements that are chemically linked to one another. This molecule is created by the chemical interaction between oxygen and magnesium.
In the balanced chemical reaction of magnesium and oxygen is 2 Mg + O₂ ⇒ 2 MgO.
Since values are not mentioned in the question, so we are considering 2 moles of magnesium and 1 mole of oxygen.
In terms of magnesium
2 moles of Mg ⇒ 2 moles of MgO
In terms of oxygen
1 mole of O₂ ⇒ 2 moles of MgO
Hence, magnesium and oxygen in 2:1 moles react to form magnesium oxide.
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What element only has 3 electrons?
Answer:
The element that only has 3 electrons is Lithium
What are the 3 properties of starch?
The properties of starch are that they are colorless and tasteless in nature and are the source of carbohydrates in our diet.
Starch are insoluble in cold water, alcohol, and other solvents.
Starch is composed of long chains of sugar molecules which are linked together linked together forming bonds and linkages. The most basic type of starch is amylose it is a linear polymer and another example is amylopectin which is a branching polymer.
Starch is the storage part in a plant where they store the excess energy in the form of glucose. This glucose is an important part of human diet and it provides energy as taken in the form of sugar.
Amylase is a starch-breaking enzyme found in saliva and the pancreas the first step in the digestion process is the breaking down of starch by enzymes.
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A method for determining the quantity of dissolved oxygen in natural waters requires a series of redox reactions. Balance the following chemical equations in that series under the conditions indicated (and include phases):
a. in basic solution
Mn^(2+) (aq) + O2 (g) ---> MnO2 (s)
b. in acidic solution
MnO2 (s) + I^(-) (aq) ---> Mn^(2+) (aq) + I2 (s)
c. in neutral solution
I2 (s) + S2O3^(2-) (aq) ---> I^(-) (aq) + S4O6^(2-) (aq)
Balance the following equation:
in basic solution: Mn²⁺ (aq) + O₂ (g) + 4OH⁻(aq) → MnO₂ (s) + 2H₂O (l)in acidic solution: MnO₂ (s) + I⁻ (aq) + 4H ⁺ → Mn²⁺ (aq) + I₂ (s) + 2H₂O (l)in neutral solution: I₂ (s) + 2S₂O₃²⁻(aq) → 2I⁻ (aq) + S₄O₆²⁻ (aq)A chemical equation is a symbolic writing of a chemical reaction. The chemical formulas of the reactants are written to the left of the equation and the chemical formulas of the products are written to the right
In basic solution:
Step-1: The number of Mn and O atoms on both sides is checked. They are equal.Step-2: The charges are looked in. The left-hand side (LHS) has net 2+ on Mn the Right-hand side (RHS) has a net O charge. Since it is a basic reaction, we neutralize the charge on Mn2+ (LHS) by adding 2 negative charges ie, 2 OH⁻ ion ⇒ Mn²⁺ + O₂+ 2OH⁻ → MnO₂Step-3: The newly introduced H on LHS is balanced on RHS by inserting a respective number of water molecules. ⇒ Mn²⁺ + O₂ + 4OH⁻ → MnO₂ + 2H₂O.Step-4: Toy to balance the number of O, H, and then Mn. ⇒ Mn²⁺ (aq) + O₂ (g) + 4OH⁻(aq) → MnO₂ (s) + 2H₂O (l)In acidic solution:
Step-1: Balance number of atoms: (O by adding H₂O)Step-2: Balance the charges by adding protons and electronsStep-3: Combine LHS and R.H.S of both equations Canal out electrons. ⇒ MnO₂ (s) + I⁻ (aq) + 4H ⁺ → Mn²⁺ (aq) + I₂ (s) + 2H₂O (l)in neutral solution:
It doesn't involve any proton or hydroxide ion in the reaction. There is no 2S₂O₃²⁻ ion and S₄O₆²⁻, the correct form is S₂O₃²⁻ and S₄O₆²⁻. This reaction comes in the third series of the Winkler method of determining Dissolved Oxygen.
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7. A speaker carries a current of 6.4 A when connected to a 120 V source. What is the power output of the speaker? O 1207 W O 982 W O 768 W O 495 W
The power output of the circuit is the product of the voltage and current passing through the circuit. Hence the power of the speaker carrying a current of 6.4 A when connected to 120 V is 768 W.
What is power?Power is the rate of work done. Its unit is Watt. Power of a device is directly proportional to the current, voltage as well as to the resistance.
The expression relating the power, current and resistance is:
P = I² R
According to Ohm's law, V = I R
Thus, P = I V.
Given that, voltage V = 120 V
current I = 6.4 A.
Thus power P = 120 V × 6.4 A = 768 W.
Therefore, the power of the speaker carrying a current of 6.4 A when it is connected to 120 V source is 768 Watt.
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What type of reaction is melting?
Ice melting is an example of an endothermic reaction because it absorbs heat.
Is melting an occurrence?When ice melts spontaneously, there is a physical shift. But if you employ a reactant, like salt, to hasten the process, it becomes a chemical reaction. While exothermic reactions emit heat, endothermic reactions absorb it. A example endothermic process is ice melting.
Why does melting not involve a chemical process?Since there is no chemical change occurring to the ice as it melts, ice melting is not a chemical reaction. The water molecules remain unchanged and continue to be water molecules.
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name the following ketones and aldehydes. when possible, give both a common name and an iupac name.
The name of the ketone will be acetone and iupac name will be propane-2-one, Heptan-2-one. Common name, Methyl n-propyl ketone.
Acetone, also referred to as propanone, would be an industrial solvent used to make plastics as well as other products.
Using specific prefixes as well as suffixes to denote the presence of a functional group, the names of organic compounds following IUPAC nomenclature are generally given and after the parent hydrocarbon chain.
It would be also known as beta-ketopropane, 2-propanone, but also dimethyl ketone. Plastic, fibres, medications, as well as other compounds are all made from acetone.
The question is incomplete, i gave answer in my general way.
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Will the depression in freezing point be the same or different if 0.1 M sugar or 0.1 M glucose is dissolved in one liter of water?
Because both treatments are non-electrolytes and produce this very same proportion of solute particles, the freezing point elevation will be identical in both solutions.
Nonelectrolyte: what is it?A substance is referred to as a nonelectrolyte if it doesn't conduct electricity in either the molten or watery form. Many molecules, including ethanol and sugar, include nonelectrolytes. These substances do not release ions when they mix with water.
What substances don't have electrolytes?A material is a nonelectrolyte if it does not ionize at all in water. Explanations: The majority of carbon compounds lack electrolytes. The majority of contribution of natural are fats, carbohydrates, and alcohols.
Briefing:⧍T ∝ molality,
molality=mole solute/weight solvent
weight of solvent = density *volume
=1000*1 kg
= ⧍T ∝ moles
moles =given mass(m) / molecular mass(M)
=0.1/M
M of sugar(sucrose)=342
M of glucose=180
⧍T∝1/M,
= ⧍T(sugar) /⧍T(glucose)
= [1/M(sugar)] / [1/M(glucose)]
= 180/342<1
therefore,
⧍T(sugar)/⧍T(glucose)<1
⧍T(sugar)<⧍T(glucose)
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Which statement best describes the usefulness of a model to investigate molecules at the microscopic level?(1 point)
A model’s usefulness depends on whether direct observations of phenomena can be made.
All models are useful.
A model’s usefulness depends on the accuracy of its predictions.
Models are not useful at all.
A statement best describes the usefulness of a model to investigate molecules at the microscopic level: A model’s usefulness depends on the accuracy of its predictions.
About scientific modelIn science, a model is a representation of an idea, an object or even a process or a system that is used to describe and explain phenomena that cannot be experienced directly. Models are central to what scientists do, both in their research as well as when communicating their explanations.
Models in marine scienceProf John Montgomery discusses how and why scientists use models, with climate change as an example.
Models are a mental visual way of linking theory with experiment, and they guide research by being simplified representations of an imagined reality that enable predictions to be developed and tested by experiment.
Why scientists use modelsModels have a variety of uses – from providing a way of explaining complex data to presenting it as a hypothesis. There may be more than one model proposed by scientists to explain or predict what might happen in particular circumstances. Often scientists will argue about the 'rightness' of their model, and in the process, the model will evolve or be rejected. Consequently, models are central to the process of knowledge-building in science and demonstrate how science knowledge is tentative.
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