answer: strontium is more reactive
steps:
strontium is heavier &
strontium is bigger, so
strontium would lose its 2 outer electrons more easily than calcium
strontium is more reactive
reactive means how easily an atom loses or gains electrons
in the periodic table :
rows are called periods
columns are called groups
strontium & calcium are both in the same column
strontium & calcium are both in group 2
strontium is chemically similar to calcium
group 2 elements can lose two electrons
group 2 metals tend to have a +2 charge
group 2 is called alkaline earth metals
factoid : radioactive strontium has been found in many bones from nuclear testing in the 1950s
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Compare and contrast sigma and pi bonds, including their shape and properties.
Sigma bonds are known to have cylindrical charge symmetry around the axis of the bond. No symmetry exists in pi bonds. Atoms with sigma bonds are less reactive. Atoms with pi bonds are highly reactive when compared to those with only sigma bonds.
calculate the mass percent of a nacl solution prepared by mixing 35.0 g nacl with 125.0 ml of pure water.
Mass percent of Sodium Chloride solution prepared by mixing is 21.875%.
A mixture is a chemical substance comprised of two or more unrelated chemical components. A mixture is a physical combination of two or more distinct substances that can take the form of solutions, suspensions, or colloids. Solutions of salt and water are an example of a homogeneous mixture, whereas sand and water and oil and water are instances of heterogeneous mixtures.
Density of Water = 1g/mL
So, 125 mL of water weighs 125g
Mass of [tex]NaCl[/tex] = 35.0g
Total mass of solution = 125g+35g = 160g
Mass % of [tex]NaCl[/tex] =(Mass of [tex]NaCl[/tex] / Total Mass ) × 100
= (35/160) × 100
= 21.875%
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A science class is going to do an experiment to investigate how water temperature changes the rate at which salt dissolves in water. What tool will be needed to measure the temperature of the water?
Answer:
thermometers
Explanation:
Answer: thermometer
Explanation: trust me ;)
how many times acidic is pOH 12 than pOH 10
Answer:
100x less acidic
Explanation:
pOH is the inverse of pH, which is a measure of the acidity or basicity of a solution. The lower the pH of a solution, the more acidic it is, and the higher the pOH, the less acidic it is.
To determine how many times more acidic a solution with a pOH of 12 is compared to a solution with a pOH of 10, we can use the formula:
pH1 / pH2 = 10^(pOH1 - pOH2)
In this case, we are given that the pOH of the first solution is 12 and the pOH of the second solution is 10. We can plug these values into the formula to calculate the ratio of acidity:
pH1 / pH2 = 10^(12 - 10)
= 10^2
= 100
Therefore, a solution with a pOH of 12 is 100 times less acidic than a solution with a pOH of 10.
a housewife used the aluminum can to keep vinegar. After sometime, it is found that the vinegar is spoiled. Give a reason.
Answer:
Explanation:She was wrong
A btu is defined as the amount of energy required to raise the temperature of one lb of water by one degree celsius.
a. True
b. False
Answer:One BTU is defined as the amount of energy required to raise the temperature of 1 lb of water through 1 degree Fahrenheit
Explanation:
this is the chemical formula for talc (the main ingredient in talcum powder): an analytical chemist has determined by measurements that there are moles of magnesium in a sample of talc. how many moles of oxygen are in the sample? be sure your answer has the correct number of significant digits.
Mg3 (Si,03),(OH), is the chemical formula for talc: an analytical chemist has determined by measurements that there are 90.4 moles of magnesium and 2.43 moles of oxygen in a sample of talc.
Talcum powder is formed from talc. Talc is a mineral created up primarily of metallic element, silicon, and oxygen. As a powder, it absorbs wet well and helps weigh down on friction, creating it helpful for keeping skin dry and serving to forestall rashes.This mineral is employed as a thickening agent and stuff. It's an ingredient in ceramics, paints, and building material.
Talc is a hydrous magnesium sheet salt with the statement Mg3Si4O10(OH)2. The elementary sheet consists of a layer of magnesium-oxygen/hydroxyl octahedra, sandwiched between 2 layers of siliconoxygen tetrahedra.
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true or false: the first step in the hydrogen burning process is a helium atom fusing with a hydrogen atom.
It is false that a helium atom fusing with a hydrogen atom is the initial stage in the hydrogen-burning process.
Four hydrogen protons and two electrons are used in the basic hydrogen fusion cycle, which results in the creation of a helium nucleus, two neutrinos, and six photons. The first stage in this three-phase process is the fusion of hydrogen into deuterium. In this collision of two protons, one proton decays into a neutron, which releases an antielectron and a neutrino.
The last proton joins the neutron to form a heavy hydrogen (deuterium) nucleus, and the newly created antielectron will annihilate with an electron to generate two very high-energy photons.
A proton is grabbed by a deuterium nucleus, which subsequently emits a photon and forms a 3He nucleus, in the second phase of the synthesis of helium-3.
The third phase involves recombining two helium-3 atoms into a single helium nucleus while emitting two protons.
Take note that for every time step 3 happens, steps 1 and 2 each occur twice. The total net energy released during this process is 26 MeV.
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what quantity is needed to convert between the moles of a given sample of a substance and its mass in grams
The molar mass of the substance is needed to convert between the moles of a given sample of a substance and its mass in grams.
What is molar mass?A compound's molar mass, which is measured in grams per mole, specifies how much of a given material weighs in one mole. In other terms, the molar mass is the sum of the masses of all the atoms that make up a mole of a certain molecule, expressed in grams. As a result, the molar mass is measured in grams/mole.
The compound's molar mass is expressed in grams per mole, or g/mol. The mass of 1 mol, expressed in the SI as g/mol, is the definition of the molar mass. Example: Water has a molar mass of 18.016 g/mol.
Thus, The molar mass of the substance is needed to convert between the moles of a given sample of a substance and its mass in grams.
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The complete question is as follows:
What quantity is needed to convert between the moles of a given sample of a substance and its mass in grams?
a the molar mass of the substance
b the density of the substance
с the physical state of the substance
d all of the above
a 150- mgmg sample of technetium-99 mm is used for a diagnostic test. if technetium-99 mm has a half-life of 6.0 hh , how many milligrams of the technetium-99 mm sample remains active 18 hh after the test? express your answer to two significant figures and include the appropriate units.
a 150- mgmg sample of technetium-99 mm is used for a diagnostic test. if technetium-99 mm has a half-life of 6.0 hh , 19 milligrams of the technetium-99 mm sample remains active 18 hh after the test.
Decay of radioactive substances follows first-order kinetics. First order rate equation is A = Ao e-kt. Ao = Intial active amount of substances .
A = Active amount of substance after certain time (t), K = Decay constant. k = ln2 / t½, k = 0.693 / 6.0 hr, k = 0.1155 / hr. A = Ao e-kt A = 150 mg x e-0.1155 hr?¹ x 18.0 hr. A = 18.758 mg.So Answer = 19 g of remains active 18 h after the test.The half-life of a quantity is the time it requires to decrease to half of its original value. In nuclear physics, the term is usually used to describe how rapidly atoms undergo radioactivity or how long stable atoms live. The term is also used to describe any kind of exponentially decaying in general.
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chemical analysis shows that the oxygen-carrying protein hemoglobin is 0.34 percent fe by mass. the actual molar mass of haemoglobin is about 65000g. how many fe atoms are in one molecule of haemoglobin.
Chemical analysis shows that the oxygen-carrying protein hemoglobin is 0.34 percent Fe by mass. the actual molar mass of hemoglobin is about 65000g. There are Fe atoms in one molecule of hemoglobin
Hemoglobin efficiently transports oxygen from the lungs to the body's tissues. Additionally, it helps in the return of carbon dioxide and hydrogen ions to the lungs. For the creation of blood, iron is crucial. Red blood cells and muscle cells contain about 70% of the iron in our bodies. Given the information, we may conclude that:
Mass of Fe in hemoglobin = 0.34% of molar mass of hemoglobin
Mass of Fe in hemoglobin = 0.34% of 65000
= (0.34 x 65000) / 100
= 221 g/mol
We now understand that the molecular weight of iron (Fe) is 55.85 g/mol.
Therefore, the quantity of iron in hemoglobin divided by the molecular mass of iron gives the amount of iron in 1 mole of hemoglobin.
= 221/55.85
= 3.957, which is approximately equal to ‘4’
In line with this, 1 molecule of hemoglobin has 4 Fe atoms in it.
The right response is hence "4".
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each of the structures for clocl , ncoh , and clno has atoms connected in the order given in their formulas. identify the type of hybridization for the central atom in each compound.
The type of hybridization for the central atom in each compound is as follows ; Initially we can determine the precise hybridization of each of the mentioned atoms by examining the structures of each molecule.
When we look at ClNO, we can see that the nitrogen atom is linked to chlorine by a single bond while also maintaining a lone pair on oxygen by double bonds. The nitrogen is therefore in a sp2 hybridized form.
As is expected for ClOCl, the molecule has two lone pairs on the oxygen atom and an sp3 hybridized oxygen atom connected to two chlorine atoms.
The carbon atom in NCOH is sp2 hybridized because it is doubly linked to oxygen.
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aluminum metal reacts with chlorine gas to form aluminum chloride the reaction starts with 3 g of chlorine gas and unlimited supply of aluminum, how many grams of aluminum chloride can be formed?
The aluminum metal reacts with chlorine gas to form aluminum chloride the reaction starts with 3 g of chlorine gas , grams of aluminum chloride formed is 3.73.
The balanced reaction is given as :
2Al + 3Cl₂ ----> 2AlCl₃
mass of Cl = 3 g
molar mass of Cl₂ = 71 g/mol
moles of Cl₂ = mass / molar mass
= 3 / 71
= 0.0422 mol
3 mole of Cl₂ produces 2 moles of AlCl₃
0.0422 mol of Cl₂ = (2/3) 0.0422
= 0.028 mol of AlCl₃
mass of AlCl₃ = molar mass × moles
= 133.34 × 0.028
= 3.73 g
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Would you expect to find calcium metal used in conducting wire or
structural materials? Why or why not?
No, we would not expect to find calcium metal used in conducting wire or structural materials. In its pure metallic form, calcium is unstable and unfit for any structural use.
Why aren't calcium-based electrical lines used?
High temperatures cause calcium to burn in the air, creating nitride and oxide. When it combines with water, hydrogen is produced. Therefore, on Earth, it cannot serve as an electrical conductor.
Is calcium an electrical conductor?
Because metals contain moving electrons, they are effective conductors of electricity. Calcium is a metal. Iodine is a non-metal, and since non-metallic elements lack mobile electrons, they are typically poor conductors or non-conductors of electricity. Consequently, solid iodine does not conduct electricity while solid calcium does. The steel cladding of the silicon-calcium alloy cored wire is covered in silicon calcium powder.
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how many atoms of mercury are in a spherical drop of mercury (hg) that has a diameter of 1.0 mm. (dhg
There are 2.1 atoms of mercury.
Calculation:
Convert 0.0000355 mol of Hg to the '# of atoms of Hg' using Avagadro's number.
Avagadro's constant = 6.022 * 1023 atoms/ mole.
Hence 'number of atoms of Hg' in the given drop of mercury is
= 0.0000355 mol of Hg * 6.022 10²³ atoms of Hg 1 mole Hg
= 2.14* 1019 atoms of Hg.
In question, we are given 1.0 mm in 2 significant figures, so our final answer must also be in 2 significant figures.
Hence the number of atoms of Hg in a given drop of mercury is 2.1x10¹⁹ atoms Plugin 2.1.
Mercury is the smallest planet in the solar system and the closest to the sun. Its orbit around the Sun lasts 87.97 Earth days, making it the shortest of any planet in the solar system.
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a chemist reacted 0.20 moles 4-aminophenol (109.13 g/mol) with 0.25 moles of acetic anhydride (102.09 g/mol) to synthesize acetaminophen. if 22 g acetaminophen (151.163 g/mol) was generated, what was the percent yield of the reaction? (only type the number, not the percent sign)
If 22 g acetaminophen (151.163 g/mol) was generated. The percent yield of the reaction is 72.78 %.
Calculation :
C₆H₇NO + C₄H₆O₃ --> C₃H₉NO₂ + C₂H₄O₂
0.20 moles 0.25 moles 22g
limiting reagrnt --> C₆H₇NO
from reaction equation
.20 mol of acetaminophen = .20*151.163 = 30.23 g
% yield = (practical/ theoritical)yield* 100 = 72.78 %
reaction yield. The reaction yield (absolute yield) of a chemical reaction is the amount of pure, dry product recovered from the reaction. Relative yield or percent yield (%) is commonly calculated to measure the efficiency of chemical reactions in organic synthesis.
Yield, also called reaction yield, is a measure of the molar amount of product to reactant consumed in a chemical reaction, usually expressed as a percentage. Yield is one of the main factors that scientists must consider in organic and inorganic chemical synthesis processes. [2] In chemical reaction engineering, “yield,” “conversion,” and “selectivity” relate to unwanted products, how much of the starting material is consumed (conversion), how much of the desired production A term used to describe the rate at which something is formed (yield). (selectivity) represented as X, Y, and S
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How many moles exist in 3,000,000 particles of gold (Au)?
Answer:
4.98 x 10^-18 mole
Explanation:
1 mole has 6.022 x 10^23 particles
so 3,000,000/(6.022 x 10^23) = 4.98 x 10^-18 mole
how many milliliters of 2.50 m hcl (aq) are required to react with 8.05 g of an ore containing 44.0% zn (s) by mass? the molecular weight of zn is 65.38 g/mol.
43.312 mL of 2.50M HCl is required to react with zinc single displacement reaction occurs.
Hydrogen gas and zinc chloride are produced quickly by the reaction of zinc with hydrochloric acid. In a single displacement reaction, zinc metal displaces hydrogen to produce zinc chloride and hydrogen gas. Because the reaction is exothermic, a significant amount of heat is produced.
The reaction goes in following order
[tex]Zn(s)+2HCl(aq)\rightarrow ZnCl_{2}(aq)+H_{2} (g)[/tex]
Percentage of Zn = (mass of Zn/mass of Ore) x 100
Mass of Zn = [tex]\frac{44 \times 8.05}{100}[/tex] = 3.54g
n Zn= [tex]\frac{3.54g}{65.38g}[/tex] per mole = 0.054144
n [tex]HCl[/tex] = 2 x 0.054144 = 0.10828
M= [tex]\frac{n}{V}\times1000[/tex]
V=[tex]\frac{n}{M}\times1000[/tex]
[tex]\frac{0.10828}{2.50}\times1000[/tex] = 43.312 mL
So 43.312 mL of 2.50M HCl is required to react with zinc.
The reaction goes in following order
[tex]Zn(s)+2HCl(aq)\rightarrow ZnCl_{2}(aq)+H_{2} (g)[/tex]
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How many elements belong to the Halogen family? List the member elements by their symbol?
Answer:
5
Explanation:
fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).
Which element has a larger atomic radius F or Be
Answer:
F
Explanation:
A calorie is defined as the amount of energy required to raise the temperature of one lb of water by one degree celsius.
a. Trueb. False
Answer: The answer is true
Explanation:
A "calorie" is a unit of energy, defined as the amount of energy needed to raise the temperature of one gram of water by one degree Celsius. The nutritional labels on food products typically tell you how many calories of digestible energy are in one serving of food, where "digestible" means that the energy stored in the chemical bonds of the molecules comprising the food can be extracted by your body. (Water for example has energy, but that energy is not chemically accessible via digestion.) To simplify understanding for typical consumers, the "calories" reported on nutritional labels actually represent kilocalories: a 170 calorie can of beer actually contains 170,000 calories of digestible energy i)
i. If a student foolishly decides to binge drink 21 beers on their 21t birthday, how many gallons of water could they have heated from room temperature (24 °C) to boiling (100 C) using an equivalent amount of digestible energy in the beer? Recall that one gallon of water is roughly 8 pounds ii)
ii. What is this energy equivalent to in BTU? A "BTU" or British Thermal Unit is also a unit of energy, defined as the amount of energy needed to raise the temperature of one pound of water by one degree Fahrenheit iii)
iii. If you had purchased an equivalent amount of electrical energy in kW-hr from the utility company, how much would you have to pay? Is this cheaper than buying beer? A kW-hr ypically costs 10 cents
The amount of energy required to increase the temperature of one gram of water by one degree Celsius is known as a "calorie," which is a unit of energy.
For example, a 170 calorie can of beer actually contains 170,000 calories of digestible energy,
so if a student foolishly decides to binge drink 21 beers, the equivalent amount of digestible energy in the beer is 21x17000.
= 3570kcal
Nutrition labels on food products typically tell you how many calories of digestible energy are in one serving, where "digestible" means that the energy stored in the chemical bonds of the molecules comprising the food can be extracted by your body.
Another heat measurement unit used in the US is the British thermal unit, or Btu. The amount of heat needed to increase 1 lb of water's temperature by 1°F is equal to 1 Btu.
As a result, the energy in BTUs E(BTU) is equivalent to 0.00029307107017 times the energy in kilowatt-hours E(kWh):
E(kWh) = 0.00029307107017 × E(BTU)
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which metal would you expect to have the highest melting point? which metal would you expect to have the highest melting point? agag tctc rbrb
Among the elements in the periodic table, tungsten metal is expected to have the highest melting point.
Tungsten, having atomic number 74 belongs to the 6th group and 6th period of the periodic table.
It is the metal with the highest melting point i.e 3422°C . For this reason, tungsten is used as a metallic component in the filaments of electric bulbs and in cathode ray tubes.
Tungsten is considered a refractory metal due to its heat-hesistance nature. on the other hand, alkali metals such as Li,Na,K have low melting points because of their large size of atoms and due to which the binding energies of the atoms in the crystal lattice is comparatively low, resulting in low melting point.
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Khloe is preheating her oven before using it to bake. Khloe wants to predict the final temperature after xx minutes. She wrote the equation y=20x+78y=20x+78, where yy represents the final temperature in degrees fahrenheit. What is the meaning of the yy-value when x=1x=1?.
The final temperature of the oven after being preheated, y is 98 degrees Fahrenheit.
What is the relationship between the final temperature and the time taken to preheat the oven?The relationship between the final temperature, y, and the time taken to preheat the oven, x is given by the equation below:
y = 20x + 78
where;
the final temperature is y,
and the time taken to preheat the oven is x
When x is equal to 1, the value of y can be determined as follows:
y = 20 (1) + 78
y = 98 degrees Fahrenheit.
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where are all the connections to the different amino acids start PLEASE HELP I NEED IT RIGHT NOWWWW my life will be over!!!!
please :)
The connections to the different amino acids in a protein are through peptide bonds.
What are amino acids?Amino acids are the basic monomer units that proteins are composed of.
Hence, proteins are polymers of monomeric units called amino acids.
Amino acids have a basic structure where a chiral carbon atom is bonded to four different groups.
The four groups present in amino acids are:
a hydrogen atoman amino group a carboxyl group, andan R groupAmino acids in proteins are linked to each other by means of peptide bonds. The peptide bond is formed from an amino group and a carboxyl group with the removal of a water molecule.
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how are components separated using distillation? the substance with the [ select ] vapor pressure is vaporized first, and then it is
The material with the lower boiling point vaporizes first when heated, then condenses and collects.
The heat that is generated during the condensation process of higher boiling vapor is what leads to the process of vaporization. Because it has such a huge surface area, the packing enables vapors to move freely between the ascending and descending directions. In the process of evaporation, the vaporization happens at a temperature lower than the boiling point, whereas in the distillation process, the vaporization happens at the boiling point.
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what is the number of moles of hydrogen atom in 6.4g of methane CH4
The number of moles of hydrogen atom in 6.4g of methane CH4 is 0.4 moles.
To find the number of moles of hydrogen atoms in 6.4 g of methane (CH4), we need to know the molar mass of methane and use the formula for converting mass to moles:
moles = mass / molar mass
The molar mass of methane is 16.04 g/mol, so we can plug in the values and solve:
moles = (6.4 g) / (16.04 g/mol)
moles = 0.4 moles
There are 0.4 moles of hydrogen atoms in 6.4 g of methane. This is because methane is a compound made up of one carbon atom and four hydrogen atoms, and the number of moles of a compound is equal to the total number of moles of all the atoms in the compound.
Since there are four hydrogen atoms in each mole of methane, there are also 0.4 moles of hydrogen atoms in 0.4 moles of methane.
Light passing through a transparent medium has a wavelength of 466 nm and a frequency of 6.20 × 1014 s-1. What is the speed of the light in the medium?
Speed =frequency × wavelength
=466 x 6.20 x [tex]10^{14}[/tex]
=2.8892 x [tex]10^{17}[/tex] m/s
What is the speed of light?
The rate at which light waves go through various materials at the speed of light. Specifically, the speed of light in a vacuum is presently calculated to be 299,792,458 metres per second.
One of nature's basic constants is the speed of light. Its importance extends far beyond its use in characterizing an aspect of electromagnetic waves. It acts as the universe's only limiting velocity, setting an upper limit on both the speed of all material particles and the speed at which signals can travel. The speed of light (c) acts as a constant of proportionality in the well-known relativity equation, E = mc2, connecting the heretofore dissimilar ideas of mass (m) and energy (E).
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Consider a PTFE molecule adjacent to a PVC molecule. Select all of the secondary bonding types that exist between these two molecules. hydrogen bonding interactions between temporarily induced and permanent dipoles interactions between dipoles that are temporarily induced B covalent bonding D ionic B metallic bonding D interactions between permanent dipoles
Choose every kind of secondary bonding that these two molecules have. 2 metallic hydrogen bonding dipoles that are both momentarily induced.
There are three different forms of interactions between molecules that result in these attractive forces: Dipole interactions, hydrogen bonding interactions, and molecule-molecule interactions are the order in which they occur (London dispersion forces). Polar molecular bonding produces hydrogen bonds, the strongest type of secondary bonding. Choose every kind of secondary bonding that these two molecules have. 2 metallic hydrogen bonding dipoles that are both momentarily induced. These can develop in water or hydrogen fluorides, for instance. When the electrons in two nearby atoms hold positions that cause the atoms to temporarily form dipoles, the consequence is the London dispersion force, a transient attractive force. Unlike main bonds, secondary bonds have substantially lower bonding energies.
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what is the iupac name of the following compound? multiple choice 4-hydroxy-3-methylbutanoic acid 3-hydroxy-2-methylbutanoic acid 1-hydroxy-2-methylbutanoic acid 3-(hydroxymethyl)butanoic acid
The IUPAC name of the given compound is option A) 4-hydroxy-3-methylbutanoic acid
The International Union of Pure and Applied Chemistry (IUPAC) nomenclature of organic chemistry is a system for naming organic chemical compounds in chemical nomenclature (IUPAC). It appears in the Blue Book, also known as the Nomenclature of Organic Chemistry. Every potential organic molecule should ideally have a name that can be used to generate a clear structural formula. Inorganic chemistry has its own IUPAC terminology as well.
Except when it is required to provide a compound an unambiguous and absolute definition, the official IUPAC naming rules are not usually followed in practice because it is preferable to avoid verbose and tiresome names in everyday communication. Sometimes, IUPAC names are shorter than earlier terms, for as when ethanol is used in place of ethyl alcohol.
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