Answer:
There are two dots are present on the left side of calcium atom which represents the unpaired electrons present in the outermost shell. This structure is presented by Lewis in order to show the number of unpaired electrons in the atom.
Explanation:
After mixing for three hours, the product is extracted into dichloromethane and the solvent is removed to give 245 mg of an oil. Using the moles of our protected aldehyde calculated earlier (2.96) and the molecular weight of the product (102 g/mol) predict the theoretical 100% yield of the product in milligrams. Round to the tenths place.
Answer:
the theoretical 100% yield of the product in milligrams is 302920 mg
Explanation:
Given the data in the question;
245 mg of an oil
Using the moles of our protected aldehyde calculated earlier (2.96)
the molecular weight of the product (102 g/mol) = 102000 mg/mol
so, the mass of aldehyde produced (100% yield) will be;
⇒ number of moles × molar mass
⇒ 2.96 mol × 102000 mg/mol
⇒ 302920 mol.mg / mol
⇒ 302920 mg
Therefore, the theoretical 100% yield of the product in milligrams is 302920 mg
Which one of the following represents an acceptable set of quantum numbers for an electron in an atom? (arranged as n, l, ml, and ms)
2, 2, -1, -1/2
3, 3, 3, 1/2
3, 3, 3, -1/2
5, 4,- 5, 1/2
2, 1, 0, 1/2
Is the number of total molecules on the left side of a balanced equation always equal to the number of total molecules on the right side of the equation
Answer:
No
Explanation:
No, but the total mass of reactants must equal the total mass of products to be a balanced equation.
Example: Consider the following reaction ...
3H₂ + N₂ => 2NH₃ and 'amu' is atomic mass units (formula weights from periodic table)
In terms of molecules, there are 4 molecules on the left (3 molecular hydrogens (H₂) and 1 molecular nitrogen (N₂) and 2 molecules of ammonia on the right side of equation arrow. ∑reactant molecules ≠ ∑product molecules.
In terms of mass of reactants & mass of products, the 3H₂ + N₂ => 6amu + 28amu = 34amu & mass of products (2NH₃) => 2(14amu) + 6(1amu) = 34amu for sum of product masses.
∑mass reactants = ∑mass products <=> 34amu = 34amu.
The expression '∑mass reactants = ∑mass products' as applied to chemical equations is generally known as 'The Law of Mass Balance'.
What BEST describes the relation of a new population to an increase in the amount of space it occupies? a - The population will die out
b - The population will remain constant
c - The population will grow exponentially
When the North Pole of one magnet is next to another North Pole of the other manger they will repel. True or false
what is a 7 letter word that starts with f: Ancient plants and animals formed into rocks.
Answer:
Fossils?
Explanation:
The burning of fossil fuels, like coal, oil, and natural gas, DO NOT contribute to the presence of greenhouse gases in the atmosphere.
True
or
False
Answer:
false statements because they are all nonrenewable resources
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AWNSER FAST PLEASE
Based on the chemical equation, use the drop-down menu to choose the coefficients that will balance the chemical equation:
(awnsers H²O -> (awnsers H² -> (awnsers O²
awnser for all drop-down menus 1,2, or 3
Answer: The coefficients are 2, 2 and 1.
Explanation: According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants.
The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced chemical equation for the given reaction is:
2H2o➡️2h2+o2
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Answer:
b
Explanation:
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Answer:
AU9NJ-BLVHV-TCLJS-54YTB
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A new drug has been released to the public and is popular among
consumers. It is effective in relieving high blood pressure. However, it has
altered some patients' personalities. Which stage of the engineering process
may address this negative side effect?
A. Evaluating test results
B. Looking for improvements
C. Screening
D. Testing
Answer: looking for improvements
Explanation:
Answer:
B. Looking for improvements
Explanation:
took the quiz and got in right on a pex
______ occur between molecules that have permanent intramolecular differences in elecronegativity.
A. Dipole-dipole interactions
B. Dispersion forces
C. Hydrogen bonds
Answer:
Dipole-dipole interactions
Explanation:
We obviously cannot wait for million years to determine the half-life of technetium, or even years to determine the half-life of plutonium. The half-life of a substance is determined using a Geiger counter, which is essentially a tube filled with an inert gas. When a particle decays and produces radiation, it briefly ionizes the gas and produces a detectable electric pulse, which is amplified and counted by a detector (before digital displays were available, you would hear clicks and see a needle register on a dial). Determine the formula for the half-life of a substance with an initial count of pulses and a count of pulses minutes later.
The question is incomplete, the complete question is;
We obviously cannot wait for 4 million years to determine the half-life of technetium, or even 87.7 years to determine the half-life of plutonium. The half-life of a substance is determined using a Geiger counter, which is essentially a tube filled with an inert gas. When a particle decays and produces radiation, it briefly ionizes the gas and produces a detectable electric pulse, which is amplified and counted by a detector (before digital displays were available, you would hear clicks and see a needle register on a dial). Determine the formula for the half-life of a substance with an initial count of No pulses and a count of N1 pulses M minutes later.
Answer:
M1/2 = 0.693/k
Explanation:
Given that the initial count rate is No pulses
The count rate after M minutes is N1
Then from;
A = Aoe^-kt
A= N1
Ao=No
I can now write;
N1 = Noe^-kM
The half life is the time taken for the activity of the radioactive nuclide to reach half its initial value. Hence;
N1/No =e^-kM = 1/2
Taking natural logarithm of both sides as shown below;
-kM1/2 = ln(1/2)
M1/2 = - (ln(1/2)/k)
M1/2 = 0.693/k
What is the molar mass of H2CO3?
(Molar mass of H = 1.0079 g/mol; C = 12.010 g/mol; O = 15.999 g/mol)
Answer:
molar mass of H2CO3 = 72.0228
Answer:
62.02 g/mol
Explanation:
Took the test and got it right. if you have enough faith in brainly youll choose the right answer
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Elements in a vertical column on the Periodic Table have similar properties and are all members of the same
of elements.
А
molecule
B
phase
С
atom
D
group
Answer:
D group
................
Which obstacle was faced by African Americans serving in the armed forces during World War II?
They were forced to serve in segregated units.
They were not subject to military conscription.
ОООО
None of them ever saw combat during the war.
They were placed under French command.
The face-centered cubic unit cell describing the structure of an ionic compound has an edge length of 207 pm. The lattice points of the unit cell are occupied by anions, and the cations are small enough so that the anions are in contact along the diagonal of the face of the unit cell. What is the ionic radius of the anion (in picometers)
Answer:
73.2 pm
Explanation:
"The anions make contact along the diagonal of the face of the unit cell, so the diagonal of the face is equal to 4 ionic anion radii. By letting r represent the ionic radius of the anion, d represent the diagonal of the face of the unit cell, and x represent the edge length, then d=4r and
d^2=x^2+x^2= 2x^2
By substituting 4r for d, the second equation becomes
(4r)^2=(2)x^2
Solving this equation for r shows that
r=(x–√2)/4
Since the edge length x is 207 pm, the ionic radius of the anion is
r= ((207 pm) X [tex]\sqrt{2}[/tex])/4=73.2 pm
Notice that the formulae used to describe atomic radii include constants with exact values. Therefore, these values do not constrain the number of significant figures."
The ionic radius of the anion in the FCC unit cell where anions are in contact along the diagonal of the face of the unit cell is 73.1pm.
What is ionic radius?Ionic radius is the distance between the center of the atom and the outermost part.
As in the question it is given that anions are in contact along the diagonal of the face of the unit cell, so the length of the diagonal is represented as: d = 4r, where
r = ionic radius
Length of edge i.e. a = 207 pm (given)
Two adjacent edges and diagonal of a FCC unit cell makes a right angle triangle, by using pythagoras theorem we can write as:
a² + a² = d²
2a² = (4r)²
2a²/16 = r²
2(207)²/16 = r²
85,698/16 = r²
0r r = 73.18 pm
Hence, 73.18 pm is the ionic radius of the anion.
To learn more about ionic radius, visit the below link:
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What atom has the largest atomic radius barium calcium magnesium radium
Answer:
Radium
Explanation:
It has the highest atomic number so it would have more shells, making it larger than the others.
which graph shows the volume amount of gas relationship expected for an ideal gas, known as Avogadro's law
Answer:
The answer is A
Explanation:
I got it right on the test
which property is a property of water
Answer: Polarity, Boiling and Freezing Points, Specific Heat Capacity, Density, Surface Tension, Heat of Vaporization and Vapor Pressure, Capillary Action, Solid State (Ice), Liquid State (Liquid Water), Gas State (Steam),
Explanation: Water molecules are polar, so they form hydrogen bonds. This gives water unique properties, such as a relatively high boiling point, high specific heat, cohesion, adhesion, and density.
Determine if the following two structures are
identical, isomers, or unrelated?
A
B
С
identical
isomers
unrelated
Answer:
its C
Explanation:
The skeletal structure shows the outline of the compound with lines and bonds. Both the structures are unrelated. Thus, option C is correct.
What are isomers?Isomers are structures with identical molecular structures but differ in the skeletal or molecular representation. They also have varied properties as compared to the parent structure.
Identical compounds are structures that have the same atoms and are arranged with the same spatial design and orientation. The number of atoms and the spatial arrangement of the two compounds is different.
Therefore, the two compounds are unrelated.
Learn more about isomers here:
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What is 6.25 in scientific notation?
Which of these elements has the lowest ionization energy?
A. Si
B. CI
C. S
D. Na
Answer:
D . Na
Explanation:
Photosynthesis needs water and carbon dioxide to happen. These 2 ingredients are called _______.
What is the main gas in our atmosphere?
Answer:
Nitrogen
Explanation:
Answer:
Yes, its nitrogen. I wrote my answer earlier in the wrong spot.
Explanation:
The atmosphere contains many gases, most in small amounts, including some pollutants and greenhouse gases. The most abundant gas in the atmosphere is nitrogen, with oxygen second. Argon, an inert gas, is the third most abundant gas in the atmosphere.
Plasma can be found naturally in
O water and ice.
O stars and lightning.
O wood and metal.
O comets and asteroids.
Answer:
stars and lightning. this is the answer ok
number of molecules in lithium oxide
4li2O
Answer:
Explanation:
Lithium is in group 1 so there's 1 outermost shell electron.
Oxygen is in group 6 so there's 6 outermost shell electron.
To react lithium with oxygen, we need 2 lithium and 1 oxygen
Each lithium transfer 1 electron to the oxygen and oxygen gain 2 electrons.
[tex]Li_{2}O\\[/tex] formed.
If there's 4 lithium oxide, 4 molecules will be there.
If you mean how many ATOMS are there, there will be 3×4=12 atoms.
What is the enthalpy change(Q) when 60.0 g of NaOH is dissolved in one litre of water, given that the temperature of the solution increased by 15.8 °C?
Answer:
ΔH = -44.029 KJ/mol
Explanation:
We are told that 60.0 g of NaOH is dissolved in one litre of water.
From conversion, 1 litre = 1000 g
From tables, specific heat capacity of water; c = 4.18 J/g/°C
We are given ΔT = 15.8 °C
Formula for the heat absorbed by the solution is given as;
Q = mcΔT
Where;
Q = Heat gained by the water
m = Mass of the water
c = Specific heat of water
ΔT = change in temperature
Thus;
Q = 1000 × 4.18 × 15.8
Q = 66044 J
The solution absorbed 66044 J and therefore it means that the dissolution of the salt gave off 66044 J.
Thus;
Enthalpy is; ΔH = -66044 J
Now, Mass of NaOH is 60 g.
We know that molar Mass of NaOH is 39.997 g/mol. Thus;
Converting to moles, we have;
n = 60/39.997
n = 1.5 mol
Now, enthalpy when 1.5 moles of NaOH are dissolved in water will be;
ΔH = -66044 J/1.5 moles
ΔH = -44029.33 J/mol
ΔH = -44.029 KJ/mol
What is the correct shape and polarity of a water molecule
Answer:
D
Explanation:
because both H's should be positive and O is supposed to be negative.