Answer:
in order of their atomic mass
The first periodic table created by Mendeleev was based on the atomic masses of elements. Later Mosely modified it based on the atomic number.
What is periodic table ?Periodic table is the classification of all the known elements based on their atomic number. There are 118 elements in periodic table now. They are classified into different groups and periods.
Mendeleev was first to create periodic table for the easy classification of elements. He classified elements based on their atomic masses. At that time there were only 60-65 elements discovered.
Later Mosley modified it to modern periodic table based on the increasing order of atomic number of elements. Therefore, the first arrangement was based on atomic masses.
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Calculate the number of phosphorus atoms in 6.2g of phosphorus
Answer:
9.33 e22
Explanation:
For moles
N=m/M
N=6.2/40
N=0.155
For total no. Of atoms:
Atoms= N × 6.02e23
Atoms= 0.155× 6.02e23
Atoms= 9.33e22
Which of these will form hydrogen bonds? a. CH2Br2 b. CH3OCH2CH3 c. H2NCH2COOH d. H2SO3 e. CH3CH2OH
Answer:
Which of these will form hydrogen bonds?
a. CH2Br2
b. CH3OCH2CH3
c. H2NCH2COOH
d. H2SO3
e. CH3CH2OH
Explanation:
A hydrogen bond is the weak electrostatic force of attraction that exists between a covalently bonded hydrogen atom and a highly electronegative atom like N,O, and F.
For example, water has a hydrogen bond between the hydrogen atoms of one molecule and the oxygen atom of another molecule.
Among the given molecules,
a. CH2Br2 does not have a hydrogen bond because it does not have N or O or F.
b. CH3OCH2CH3 does not have a hydrogen bond.
Due to the absence of -OH or -NH or H-F bonds.
c. H2NCH2COOH shows hydrogen bonding.
d. H2SO3 has hydrogen bonding.
Due to the presence of -OH bond.
e. CH3CH2OH has hydrogen bonding.
Due to the presence of -OH bond.
Stae the change in oxidation state of iron during the reactiong of iron extraction
Answer:
3
Explanation:
The reaction for the extraction of Iron is :-
2Fe2O3(s) + 3C(s) → 4Fe(l) + 3CO2(g)
O.S. of Fe in Fe2O3 is 3 and O.S. of Fe(l) is 0change in oxidation state (O.S.) = higher O.S - lower O.S
= 3 - 0
= 3
Hi, in some texts number of water molecules released during polymerization is 2n but in others 2n-1 , why?
Answer:
Explanation:
Because you only have one repeat unit, n=1. 2n-1 becomes 2(1)-1 which is equal to one, meaning one molecule of H2O is produced, as is shown by the top condensation polymerisation reaction.
If you had two repeat units, n=2 so 2n-1=3. Three H2O molecules are produced because you would need two molecules of each reactant so three condesation reactions would occur and three molecules of H2O would be released.
Give structural formula of ethylene. What type of bond is found in between carbon and hydrogen? Why is the bond between carbon and carbon weak in it?
Answer:
See explanation
Explanation:
The structure of ethylene is shown in the image attached. The two carbon atoms have a double covalent bond between them.
The two carbon atoms are sp2 hybridized. The bond between them is a covalent bond, there is one pi bond and one sigma bond between the carbon atoms. Between carbon and hydrogen, there are covalent bonds also. The covalent bonds are sigma bonds.
The pi bonds between carbon atoms is weaker than the sigma bonds between the carbon atoms. This is because, the side-by-side overlap the p orbitals in a pi bond is less effective than the end-to-end overlap of a sigma bond.
Si se analizan muestras de Al2O3 en diversos laboratorios se encuentra que todas tienen 52,94% de aluminio (Al) y 47,06% de oxígeno (O). Este dato experimental corresponde a lo expresado por la ley de:
A) La ley de las proporciones definidas
B) La ley de las proporciones múltiples
C) La ley de la conservación de la masa
D) La ley de la conservación de la energía
If 250 grams of water is to be heated from 24.0°C to 100.0°C to make a cup of tea, how much
heat must be added? The specific heat of water is 4.18 J/g∙C
Answer:
[tex]\boxed {\boxed {\sf 79,420 \ J}}[/tex]
Explanation:
We are given the mass, a change in temperature, and the specific heat of water. We should use the following formula to solve this problem.
[tex]q=mc\Delta T[/tex]
In this formula, m is the mass, c is the specific heat, and ΔT is the change in temperature.
We know there are 250 grams of water and the specific heat of water is 4.18 J/g · °C.
We are given two temperature, so have to find the change in temperature. This is the difference between the initial temperature and final temperature. The water is heated from 24 °C to 100 °C. Therefore, the initial is 24 and the final is 100.
[tex]\bullet \ \Delta T= T_{final} - T_{initial} \\\bullet \ \Delta T=100 \textdegree C - 24 \textdegree C\\\bullet \Delta T= 76 \textdegree C[/tex]
Now we know all three of the variables and we can substitute them into the formula.
[tex]\bullet \ m= 250 \ g\\ \bullet \ c=4.18 \ J/g \textdegree C \\ \bullet \ \Delta T= 76 \textdegree C[/tex]
[tex]q= (250 \ g)( 4.18 \ J/g * \textdegree C)( 76 \textdegree C)[/tex]
Multiply the first two numbers together. The units of grams will cancel.
[tex]q= (1045 \ J/\textdegree C)(76 \textdegree C)[/tex]
Multiply again. This time, the units of degrees Celsius cancel.
[tex]q= 79420 \ J[/tex]
79, 420 Joules of heat must be added.
Amino acids that must be obtained through the diet are called O A) cholesterol. OB) non-essential amino acids. o C) essential amino acids. The OD) peptides.
Answer:
I belive C: essential amino acids
Explanation:
They can t be made from the body so they must be obtained my food
Help me guys ☹️please
Answer:
Coriolis Effect
Explanation:
The Coriolis Effect is caused by Earths rotation. We can not only see this affecting how winds move, but also where storms form and the movement of oceans currents.
What is the balance equation for
_ Ba + _ HNO3 —> _ H2 + _ Ba(NP3)2
_ H3PO4 + _ NaOH —> _ H2O + _ Na3PO4
1st one
2_2_2
2nd one
3_1_1_3
i looked it up
A solar energy company learns of several recent cyber-attacks targeting other companies in their industry and realizes they could be next. The company initiates an analysis to weigh the measures needed to counter the potential threat and minimizing the impact to their business in case those are exploited. Which security principle is illustrated in this example?
What is the weight on Earth of an apple with mass 150g?
what is a saturted solution
Answer:
Please find the definition and further explanation below
Explanation:
Based on the ability for the solvent (liquid substance) to dissolve a solute (solid substance), a solution can either be unsaturated, saturated or supersaturated. A SATURATED SOLUTION is that which contains the maximum amount of solute a solvent can possibly dissolve.
In other words, a saturated solution can no longer dissolve anymore solute, and hence, any further solute added forms crystals or makes the solution supersaturated.
In a few sentences, describe the molecular polarity and the intermolecular forces present in ammonium lauryl sulfate.
The description of the molecular polarity and the intermolecular forces present in ammonium lauryl sulfate should be explained below.
What is ammonium lauryl sulfate?The common name of it should be likely ammonium lauryl sulfate (ALS) and its molecular formula should be (CH3(CH2)10CH2OSO3NH4).
Also, one intermolecular formula that should be presented in the molecule should be considered as the electrostatic forces of attraction that lies between the non-polar chain and the polar ending group.
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What mass of N2O5 will result from the reaction of 6.0 mol of NO2 if there is a 61.1% yield in the reaction
Answer:
2.0 × 10² g
Explanation:
Step 1: Write the balanced equation
2 NO₂ + 0.5 O₂ ⇒ N₂O₅
Step 2: Calculate the theoretical yield, in moles, of N₂O₅
The molar ratio of NO₂ to N₂O₅ is 2:1.
6.0 mol NO₂ × 1 mol N₂O₅/2 mol NO₂ = 3.0 mol N₂O₅
Step 3: Calculate the theoretical yield, in grams, of N₂O₅
The molar mass of N₂O₅ is 108.01 g/mol.
3.0 mol × 108.01 g/mol = 3.2 × 10² g
Step 4: Calculate the real yield, in grams, of N₂O₅
real yield = theoretical yield × percent yield
real yield = 3.2 × 10² g × 61.1% = 2.0 × 10² g
What is the salt produced in the stomach when calcium carbonate reacts with and neutralizes excess hydrochloric acid?
The salt CaCl2 (calcium chloride) and water (H2O) are formed in this reaction. Also formed is the gas carbon dioxide (CO2) which may cause a bloated feeling in the stomach. The acid that is secreted in your stomach is approximately 0.1 M (moles per liter) hydrochloric acid.
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Which describes the difference between a claim and a scientific claim?
Claims are based more on truth than scientific claims are.
Anyone can make a claim, but a scientific claim is backed by experimental evidence.
Claims are based on evidence and scientific claims are made by scientists.
Controlled experiments are used in claims, while scientific claims use multiple trials.
Answer:
B. Anyone can make a claim, but a scientific claim is backed by experimental evidence.
<3 Have a nice day!!
Answer:
the awnser is B i got it right
Explanation:
True or false, The atomic number of an element is a whole number that decreases as you read across each row of
the periodic table from left to right.
Answer:
I believe it's false because the atomic number is the number of protons in the nucleus of an atom.
Give a real-world example of an energy transformation that uses two of the following forms of energy: chemical, mechanical, nuclear, gravitational, radiant, electrical, thermal (heat), and/or sound.
Answer:
Nuclear energy gets converted into heat energy during a detonation and is also used in nuclear power plants where the heat energy form the nuclear energy gets converted into mechanical energy by converting water into steam, rotating the turbines and converting that into electrical energy
Explanation:
Or heat engines, such as the internal combustion engine used in cars, or the steam engine. (Heat - Mechanical energy)
A 115.0-g sample of oxygen was produced by heating 400.0 g of potassium chlorate. 2KClO3 Right arrow. 2KCI 3O2 What is the percent yield of oxygen in this chemical reaction
Answer:
Percentage yield of O₂ = 73.4%
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
2KClO₃ —> 2KCl + 3O₂
Next, we shall determine the mass of KClO₃ that decomposed and the mass of O₂ produced from the balanced equation. This can be obtained as follow:
Molar mass of KClO₃ = 39 + 35.5 + (3×16)
= 39 + 35.5 + 48
= 122.5 g/mol
Mass of KClO₃ from the balanced equation = 2 × 122.5 = 245 g
Molar mass of O₂ = 2 × 16 = 32 g/mol
Mass of O₂ from the balanced equation = 3 × 32 = 96 g
SUMMARY:
From the balanced equation above,
245 g of KClO₃ decomposed to produce 96 g of O₂.
Next, we shall determine the theoretical yield of O₂. This can be obtained as follow:
From the balanced equation above,
245 g of KClO₃ decomposed to produce 96 g of O₂.
Therefore, 400 g 245 g of KClO₃ will decompose to produce
= (400 × 96)/245 = 156.7 g of O₂.
Thus, the theoretical yield of O₂ is 156.7 g
Finally, we shall determine the percentage yield of O₂. This can be obtained as follow:
Actual yield of O₂ = 115.0 g
Theoretical yield of O₂ = 156.7 g
Percentage yield of O₂ =?
Percentage yield = Actual yield /Theoretical × 100
Percentage yield = 115/156.7 × 100
Percentage yield = 11500/156.7
Percentage yield of O₂ = 73.4%
Using the balanced equation below, how many grams of cesium fluoride would be required to make 73.1 g of cesium xenon heptafluoride?
CSF + XeF6 → CsXeF7
Answer: A mass of 84.46 g of cesium fluoride would be required to make 73.1 g of cesium xenon heptafluoride.
Explanation:
Given: Mass of cesium xenon heptafluoride = 73.1 g
The molar mass of cesium xenon heptafluoride is 131.3 g/mol. So, moles of [tex]CsXeF_{7}[/tex] is calculated as follows.
[tex]Moles = \frac{mass}{molar mass}\\= \frac{73.1 g}{131.3 g/mol}\\= 0.556 mol[/tex]
According to the given equation, 1 mole of CsF yields 1 mole of [tex]CsXeF_{7}[/tex].
Hence, moles of CsF reacting will also be equal to 0.556 mol. As molar mass of CsF is 151.9 g/mol so its mass is calculated as follows.
[tex]Moles = \frac{mass}{molarmass}\\0.556 mol = \frac{mass}{151.9 g/mol}\\mass = 84.46 g[/tex]
Thus, we can conclude that a mass of 84.46 g of cesium fluoride would be required to make 73.1 g of cesium xenon heptafluoride.
What is the basic difference between exergonic and endergonic reactions? Group of answer choices Exergonic reactions release energy; endergonic reactions absorb it. Exergonic reactions involve ionic bonds; endergonic reactions involve covalent bonds. Exergonic reactions involve the breaking of bonds; endergonic reactions involve the formation of bonds. In exergonic reactions, the reactants have less chemical energy than the products; in endergonic reactions, the opposite is true.
Answer: the basic difference is Exergonic reactions release energy and an endergonic reactions absorb energy .
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The electrolysis of water forms H2 and O2. 2H2O Right arrow. 2H2 O2 What is the percent yield of O2 if 10.2 g of O2 is produced from the decomposition of 17.0 g of H2O
Answer:
67.5%
Explanation:
Step 1: Write the balanced equation for the electrolysis of water
2 H₂O ⇒ 2 H₂ + O₂
Step 2: Calculate the theoretical yield of O₂ from 17.0 g of H₂O
According to the balanced equation, the mass ratio of H₂O to O₂ is 36.04:32.00.
17.0 g H₂O × 32.00 g O₂/36.04 g H₂O = 15.1 g O₂
Step 3: Calculate the percent yield of O₂
Given the experimental yield of O₂ is 10.2 g, we can calculate its percent yield using the following expression.
%yield = (exp yield / theoret yield) × 100%
%yield = (10.2 g / 15.1 g) × 100% = 67.5%
Help ASAP only right answers only no spam don’t answer if you don’t know
Answer: Solve problems
Which best describes a swimming pool?
A.
It is a solute.
• B.
It IS
solvent.
C.
It is solution.
D.
It is a reactant.
•
E.
It is a product.
Answer:
Swimming pool is an example of solution
Explanation:
It has water (solvent) and dissolve ion (solute)
Answer:
it is a solution
Explanation:
the combining of (water and Cl and other pool chemicals) make it a solution.
during summer water kept in an earthen pot become cool because of the phenomenon of
During summer water kept in an earthen pot become cool because of the phenomenon of evaporation.
Which is a feature of a single replacement reaction?
Answer:
A typical characteristic of a single-replacement reaction is that there is one element as a reactant and another element as a product. will not because bromine is below fluorine on the periodic table. This is just one of many ways the periodic table helps us understand chemistry.
Explanation:
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cual es el tamaño de partícula del alcohol
Answer:
Las botellas de alcohol vienen en una variedad de tamaños. El estándar es de 750 ml, que también se conoce como "un quinto" porque es 1/5 de galón. Otros tamaños comunes de botellas de alcohol son 50ml, 100ml, 200ml, 375ml, 1L y 1.75L.
Explanation:
convert 256 ml to kl
Answer:
0.000256
Explanation:
Formula:
Divide the value volume by 1e+6
1 kl equal to 1000000ml
What are two factors that determine the concentration of hydronium (or hydroxide) ions in an acid (or base) solution?
Answer:
hydronium and hydroxide ions are present both in pure water and in all aqueous solutions, and their concentrations are inversely proportional as determined by the ion product of water (Kw). The concentrations of these ions in a solution are often critical determinants of the solution’s properties and the chemical behaviors of its other solutes, and specific vocabulary has been developed to describe these concentrations in relative terms. A solution is neutral if it contains equal concentrations of hydronium and hydroxide ions; acidic if it contains a greater concentration of hydronium ions than hydroxide ions; and basic if it contains a lesser concentration of hydronium ions than hydroxide ions.
Answer:
hydronium and hydroxide ions are present both in pure water and in all aqueous solutions, and their concentrations are inversely proportional as determined by the ion product of water
Explanation:
Not my work! I hope this helps!