Answer:
electrons
Explanation:
In an atom, you can have varying numbers of electrons, depending on if its an ion or not. You can use the orbitals to see the energy level of the atom.
An atom has only one number of protons. The number of protons cannot vary.
Which of the following is a buffer system?
A. NaCl and NaNO3
B. H2CO3 and KHCO3
C. HCl and NaOH
D. H2O and HCl
E. NaCl and NaOH
Answer:
B. H2CO3 and KHCO3
Explanation:
The buffer system is a system in which the solution deny for change in the ph level i.e. at the time when the acid is added to it. It can be made either in a weak acid and salt or can be a weak base and its salt. Now when the acid is added to a buffer so the ratio is not impacted due to which it does not change sufficient for pH level
As per the given options, the third one is correct as the H2CO3 denotes a weak acid and the KHCO3 represents the salt. And these two solution does not create any change in the level of pH
Therefore the option B is correct
Part Of flowers that contains pollen is
Please answer right
Answer:
its the stamen, it also supports the Anther.
Answer:
The Stamen
Explanation:
The stamen is a slender filament supporting the anther, it is what produces and holds pollen in flowers.
When measuring solid NaOH in pellet form, explain why you won’t be able to measure exactly 1.000 grams. What are the consequences of this?
Answer:
Explanation:
Pellet form of NaOH is highly hygroscopic . It absorbs moisture from air and its weight is increased by the time one tries to weigh one gram of it . Moreover it also reacts with carbon dioxide gas of atmosphere to form sodium carbonate .
2 NaOH + CO₂ = Na₂CO₃ + H₂0.
It also increases its weight .
3 points
What is the energy (Joules) of violet light with a frequency = 3.43 x 10^14
1/s? *
4.54x10^-19 J
1.99x10^-25 J
1.93 x 10^-48 J
O 2.27 x 10^-19 J
Pls help me
Answer:
4.54x10^-19 J
1.99x10^-25 J
1.93 x 10^-48 J
find the R when p=6000,T=3 yrs 6 month ,I=1155
R= 1155×100/6000×3/12
R= 1155×2/3
R=770The flask contains 10.0 mL of HCl and a few drops of phenolphthalein indicator. The buret contains 0.160 M NaOH. It requires 18.2 mL of the NaOH solution to reach the end point of the titration. A buret filled with a titrant is held above a graduated cylinder containing an analyte solution. What is the initial concentration of HCl
Answer:
Approximately [tex]0.291\; \rm M[/tex] (rounded to two significant figures.)
Explanation:
The unit of concentration [tex]\rm M[/tex] is the same as [tex]\rm mol \cdot L^{-1}[/tex] (moles per liter.) On the other hand, the volume of both the [tex]\rm NaOH[/tex] solution and the original [tex]\rm HCl[/tex] solution here are in milliliters. Convert these two volumes to liters:
[tex]V(\mathrm{NaOH}) = 18.2\; \rm mL = 18.2 \times 10^{-3}\; \rm L = 0.0182\; \rm L[/tex].[tex]V(\text{$\mathrm{HCl}$, original}) = 10.0\; \rm mL = 10.0\times 10^{-3}\; \rm L = 0.0100\; \rm L[/tex].Calculate the number of moles of [tex]\rm NaOH[/tex] in that [tex]0.0182\; \rm L[/tex] of [tex]0.160\; \rm M[/tex] solution:
[tex]\begin{aligned} n(\mathrm{NaOH}) &= c(\mathrm{NaOH})\cdot V(\mathrm{NaOH})\\ &= 0.160\; \rm mol \cdot L^{-1} \times 0.0182\; \rm L \approx 0.00291\; \rm mol\end{aligned}[/tex].
[tex]\rm HCl[/tex] reacts with [tex]\rm NaOH[/tex] at a one-to-one ratio:
[tex]\rm HCl\; (aq) + NaOH\; (aq) \to NaCl\; (aq) + H_2O\; (l)[/tex].
Coefficient ratio:
[tex]\displaystyle \frac{n(\mathrm{HCl})}{n(\mathrm{NaOH})} = 1[/tex].
In other words, one mole of [tex]\rm NaOH[/tex] would neutralize exactly one mole of [tex]\rm HCl[/tex]. In this titration, [tex]0.291\; \rm mol[/tex] of [tex]\rm NaOH\![/tex] was required. Therefore, the same amount of [tex]\rm HC[/tex] should be present in the original solution:
[tex]\begin{aligned}&n(\text{$\mathrm{HCl}$, original})\\ &= n(\mathrm{NaOH})\cdot \frac{n(\mathrm{HCl})}{n(\mathrm{NaOH})} \\ &\approx 0.00291\; \rm mol \times 1 = 0.00291\; \rm mol\end{aligned}[/tex].
Calculate the concentration of the original [tex]\rm HCl[/tex] solution:
[tex]\displaystyle c(\text{$\mathrm{HCl}$, original}) = \frac{n(\text{$\mathrm{HCl}$, original})}{V(\text{$\mathrm{HCl}$, original})} \approx \frac{0.00291\; \rm mol}{0.0100\; \rm L} \approx 0.291\; \rm M[/tex].
What determines the shape and function of a protein?
The shape and function of a protein are primarily determined by its three-dimensional structure, which is a result of its primary, secondary, tertiary, and quaternary structures.
Primary Structure: The primary structure of a protein is the linear sequence of amino acids that make up the polypeptide chain. The sequence is dictated by the genetic information encoded in the DNA of the gene that corresponds to the protein. Each amino acid in the sequence is represented by a specific codon in the DNA, and this sequence of amino acids forms the backbone of the protein.
Secondary Structure: The secondary structure refers to the local spatial arrangement of the polypeptide backbone, which is stabilized by hydrogen bonds between amino acids. The two most common secondary structures are alpha-helices and beta-sheets. These structures are important for the stability and folding of the protein.
Tertiary Structure: The tertiary structure is the three-dimensional folding of the entire polypeptide chain, including the secondary structure elements. Various interactions, such as hydrogen bonds, disulfide bridges, ionic interactions, hydrophobic interactions, and van der Waals forces, play a crucial role in stabilizing the tertiary structure. This folding brings distant parts of the polypeptide chain close together, contributing to the unique shape of the protein.
Quaternary Structure: Some proteins are composed of multiple polypeptide subunits, and the way these subunits come together forms the quaternary structure of the protein. The interactions between the individual subunits contribute to the overall structure and function of the complex protein assembly.
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PLEASE HELP ME, I HAVE NO IDEA HOW TO DO THIS :(
Lol . same here. If u get any ideas please let me know
Answer:
See the picture you have to write like this
3. Calculate each of the following:
a) kg of 4.6x1021 molecules of nitrogen dioxide
b) moles of chlorine atoms in 0.615 g of C2H4Cl2
c) number of hydride ions in 5.82 g of strontium hydride
Answer:
the answers are at the very bottom of each picture
Explanation:
i really hope this helps you:)
can some one help The function of the cell wall in a plant cell is Question 2 options: Allowing material to pass in and out of the cell Uses carbon dioxide, water and energy from the sun to make sugar Breaks sugar down into ATP which the cell can use for energy Provides support and protection for the cell
Answer:
the protection one
Explanation:
the cell wall acts a barrier
If ΔH vaporization of water (H2O) is 40.7 kJ/mol,
and the ΔS for vaporization of H2O is 109 J/mol K,
what is ΔG for water vaporization at 350K?
Include units.
Answer:
2.6 kJ/mol
Explanation:
Step 1: Given data
Standard enthalpy of vaporization of water (ΔH°): 40.7 kJ/molStandard entropy of vaporization of water (ΔS°): 109 J/mol.KAbsolute temperature (T): 350 KStandard Gibbs free energy of vaporization of water (ΔG°): ?Step 2: Calculate ΔG°
We can calculate ΔG° using the following expression.
ΔG° = ΔH° - T × ΔS°
ΔG° = 40.7 kJ/mol - 350 K × 0.109 kJ/mol.K
ΔG° = 2.6 kJ/mol
The change in Gibbs free energy, ΔG for the water is 2.55 KJ/mol
Data obtained from the questionFrom the question given above, the following data were obtained:
Standard enthalpy of vaporization of water (ΔH°) = 40.7 kJ/molStandard entropy of vaporization of water (ΔS°) = 109 J/Kmol = 109 / 1000 = 0.109 KJ/Kmol Absolute temperature (T) = 350 KStandard Gibbs free energy (ΔG°) =? How to determine the Gibbs free energy, ΔG°The Gibbs free energy, ΔG° can be obtained as illustrated below:
ΔG° = ΔH° – TΔS°
ΔG° = 40.7 – (350 × 0.109)
ΔG° = 40.7 – 38.15
ΔG° = 2.55 KJ/mol
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Decaying plants and animals are important to an ecosystem because they
A.
cause disease in living organisms.
B.
reduce soil erosion.
C.
recycle oxygen to the air.
D.
return nutrients to the soil.
Answer:
The option D is correct answer.
Decaying pants and animals are important to the ecosystem as they return the nutrients to the soil.
What is an ecosystem?Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.
Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.
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Consider a closed container of gas that is a mixture of 30% CO2 and 70% N2 at room temperature 20°C. The gases are in thermal equilibrium with one another. a) Which has the higher kinetic energy, the average CO2 or N2 molecule? b) What is that root-mean-square velocity of a CO2 molecule? For reference, a carbon atom has 6 protons, a nitrogen atom has 7 protons, and an oxygen atom has 8 protons.
Answer:
a. the kinetic energy will be the same.
b. [tex]\mathbf{\overline v = 407.65 \ m/s}[/tex]
Explanation:
The kinetic theory deals with how the arrangement of particles of a substance determines the properties that substance will possess and the state in which it is likely to be found under a given set of conditions. From the postulates of the kinetic theory of gases, The average kinetic energy of the gas molecules is a measure of the temperature of the gas molecules, This implies that the kinetic energy is dependent on the temperature.
i.e
[tex]K.E = \dfrac{3}{2} \ KT[/tex]
where ;
K = Boltzmann Constant
Since the given gases are in thermal equilibrium, therefore, the kinetic energy will be the same.
b).
The root mean square velocity of CO2 molecule is represented by the equation :
[tex]\overline v = \sqrt{\dfrac{3RT}{M_m}}[/tex]
[tex]\overline v = \sqrt{\dfrac{3\times 8.314 \ J/K /mole \times (293.15 \ K ) }{44 \times 10^{-3} \ kg / mol}}[/tex]
[tex]\overline v = \sqrt{\dfrac{7311.7473 }{44 \times 10^{-3} }}[/tex]
[tex]\overline v = \sqrt{166176.075 \ m/s}[/tex]
[tex]\mathbf{\overline v = 407.65 \ m/s}[/tex]
Over the course of many years, a rural farm town becomes more urban. Which of the following will most likely happen in the town as a result of this urbanization?
Answer:
Explanation:
Rivers may be contaminated by sewage.
I do hope I helped you! :)
What is the mass, in grams, of the ethyl alcohol that exactly fills a 220 mL container? The density of ethyl alcohol is 0.789 g/mL. Group of answer choices 170 g 173.58 g 280 g 278.833967 g
Answer:
[tex]m=173.58g[/tex]
Explanation:
Hello,
In this case, since the density is the ratio of the mass and volume:
[tex]\rho =\frac{m}{V}[/tex]
For the given density and volume, the correct mass which fills the given volume is:
[tex]m=\rho *V=0.789g/mL*220mL\\\\m=173.58g[/tex]
Best regards.
E
1
1 point
Which of the following is an elemental substance?
Select all the correct answers.
Mercury
2
Oxygen (O2)
3
Platinum
Chlorine (C12)
Carbon Dioxide (CO2)
Answer:
oxygen and Carbon dioxide
explain why division by zero is undefined
Answer:
Division by zero is undefined because there is no other number to divide it by.
Explanation:
Unlike 2/2, 2/0 doesn't have anything to divide the 2 by which makes it undefined and impossible to solve.
The division by zero is undefined, because whatever response we may give, we will then have to concur that the answer times 0 = 1, which is illogical because anything multiplied by zero is zero.
Why division by zero is undefined ?Since any attempt at definition results in a contradiction, the outcome of a division by zero cannot be defined. a=r*b. r*0=a. (1) (1) But because r*0=0 for all r, there is no solution to the equation unless a=0 (1).
Again, mathematicians have left zero divided by zero as an open problem because they are both equally valid and, to be honest, neither of them is consistent with the rest of mathematics.
Mathematically, it is impossible to divide a number by zero, just as in this illustration. Or, at the very least, there isn't currently a means to do that. Numerous attempts have been made to figure out how to divide by zero, as mathematicians are constantly looking for solutions to intriguing mathematical issues.
Thus, The division by zero is undefined, because whatever response we may give, we will then have to concur that the answer times 0 = 1.
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Oxalic acid, H2C2O4*2H2O (molar mass = 126.07 g/mol) is oftenused as a primary standard for the standardization of a NaOHsolution. If 0.147 g of oxalic acid dihydrate is nutralizedby 23.64mL of a NaOH solution, what is the molar concentration ofthe NAOH solution? Oxalic acid is a diprotic acid. (What is thebalanced equation?)
Answer:
0.09865M of NaOH
Explanation:
As a diprotic acid, 1 mole of oxalic acid reacts with 2 moles of NaOH as follows:
H2C2O4 + 2 NaOH → 2 H2O + Na2C2O4
With the mass of the acid and its molar mass we can obtain the moles of oxalic acid. Twice these moles are the moles of NaOH in the solution. As you required 23.64mL = 0.02364L of the NaOH, you can knkow molarity, thus:
Moles Oxalic acid:
0.147g * (1mol / 126.07g) = 1.166x10⁻³ moles Oxalic acid.
Moles NaOH:
1.166x10⁻³ moles Oxalic acid * (2 moles NaOH / 1 mole H2C2O4) = 2.332x10⁻³ moles NaOH
Molarity:
2.332x10⁻³ moles NaOH / 0.02364L =
0.09865M of NaOHExactly how many -OH groups are found in a 6 carbon alditol?
Answer:
The number of OH group found in found in a 6 carbon alditol is 6
Explanation:
The structure of a 6 carbon alditol is shown on the first uploaded image
how many atoms are in 2 miles of h2o
Answer:
one mole of water contains 6.02 x 1023 MOLECULES of water.
But each molecule of water contains 2 H and 1 O atom = 3 atoms, so there are approximately 1.8 x 1024 atoms in a mole of water.
Explanation:
hope it helps you paigegeorge
1- Science that deals with the identification and quantification of the components of material systems
A)Analytical Science
B)Biochemistry
C)Organic Chemistry
D) Inorganic Chemistry
Q1-(30 Marks) Choose the correct answer
Answer:
Analytical science
Explanation:
Which statement correctly compares an atom of an alkali metal with an atom of the alkaline earth metal next to it on the periodic table? aThe alkali metal atom forms a +1 ion, while the alkaline earth metal atom forms a +2 ion. bThe alkali metal atom forms a +2 ion, while the alkaline earth metal atom forms a +1 ion. cThe alkali metal atom has one less shell of electrons than the atom of the alkaline earth metal. dThe alkali metal atom has one more shell of electrons than the atom of the alkaline earth metal.
The atom of alkaline earth metal has one more proton and one more electron than the alkali metal that is next to it to the left on the periodic table. Then the atomic number of the alkali metal is one unit less than the atomic number of the alkaline earth metal next to it
Answer:
A) The alkali metal atom forms a +1 ion, while the alkaline earth metal atom forms a +2 ion.
Explanation:
Let's evaluate each answer.
A: The alkali metal atom forms a +1 ion, while the alkaline earth metal atom forms a +2 ion.
This means that the alkali metal atom has to lose 1 valence electron to form a +1 ion while the alkaline earth metal atom has to lose 2 valence electrons to form a +2 ion. This is accurate because alkali metal atoms have 1 valence electron while alkaline earth metal atoms have 2, so the statement is correct.
B: The alkali metal atom forms a +2 ion, while the alkaline earth metal atom forms a +1 ion.
This would mean that the alkali metal atom has to lose 2 valence electrons to form a +2 ion, while the alkaline earth metal has to lose 1 valence electron to form a +1 ion. This is incorrect because alkali metal atoms only have 1 valence electron and will become a +1 ion when losing that electron, while alkaline earth metals have 2 valence electrons and will form a +2 ion upon losing them.
C: The alkali metal atom has one less shell of electrons than the atom of the alkaline earth metal.
This would mean that the alkali metal atom would be located one period higher up than the alkaline earth metal atom. This is untrue, because the question states that the alkali metal atom is located directly next to the alkaline earth metal atom, so they have the same amount of electron shells.
D: The alkali metal atom has one more shell of electrons than the atom of the alkaline earth metal.
This would mean that the alkali metal atom would be located one period lower on the periodic table than the alkaline earth metal atom. Similar to the previous statement, this is untrue because the question states that they are located directly next to each other, or on the same period.
(Also, I just took this quiz and e2020 says it's right.)
Which of the following is considered an ionic solid? a) (NH4)2CO3 b) CBr4 c) SeBr2 d) XeF4 e) None of the above is an ionic solid.
Answer: NH4)2CO3
Explanation:
Ionic solids are the solids that are simply held together by ionic bonds. Ionic bonds are lattices that are typically made up of oppositely charged ions and they usually possess a high melting point.
An example of ionic bond is NH₄)₂CO₃ which is referred to as Ammonium carbonate. This is a salt and it readily degrades upon heating to carbon dioxide and gaseous ammonia.
You bought a new car and estimated that your monthly payment would be $312. However, your actual payment amount is $325. How much error was in your estimate?
In which of does the convection only occur in
A. Gases
B. Fluids
C. Liquids
D. Solids
Answer:
B. Fluids
I hope this helps!
Answer:
B
Explanation:
In a compound the elements are _____ together, whereas in a mixture the substances are blended together.
Answer:
bonded
Explanation:
Compounds are two elements bonded together.
A mixture is multiple substances blended together. The substances aren't bonded together and can easily be extracted from each other.
How many grams are there in 1.00x10 24 molecules of BCI3
Answer:
194.569 g
Explanation:
6.022×10^23 molecules = 117.17 g
1 molecules = 117.17/ 6.022×10^23
So, 1×10^24 molecules = (117.17×1×10^24)/(6.022×10^23)= 194.569 g
A state of dynamic equilibrium, Ag2CO3(s) 2Ag^+(aq) + CO3^2-, exists in solution.
What shift occurs in the equilibrium if HCl (aq) is added to the system? Explain please
Answer:
The equilibrium will shift to the right producing more Ag⁺ and CO₃²⁻
Explanation:
In the equilibrium:
Ag₂CO₃(s) ⇄ 2Ag⁺(aq) + CO₃²⁻(aq)
The change in concentration of Ag⁺ or CO₃²⁻ will shift the equilibrium
The addition of HCl(aq) (Dissociates in H⁺ and Cl⁻ ions) produce the formation of AgCl. The reaction is:
Ag⁺(aq) + Cl⁻(aq) ⇄ AgCl(s)
That means the addition of HCl decrease concentration of Ag⁺.
Based on LeChatelier's principle: As the Ag⁺ decreases, the equilibrium will decrease amount of Ag₂CO₃ producing more Ag⁺ and CO₃²⁻. That is:
The equilibrium will shift to the right producing more Ag⁺ and CO₃²⁻There are________
neutrons in the stable isotope of rhenium (Re-
185)
A.134
B.90
C.125
D.110
There are 110 neutrons in the stable isotope of rhenium. The correct option is D.
What are neutrons?A neutron is a subatomic particle that exists in the nucleus of all atoms except simple hydrogen. The name of the particle comes from the fact that it has no electrical charge; it is neutral. Neutrons have a very high density.
With the exception of the single-proton hydrogen nucleus, nuclei require neutrons to be stable. Neutrons are abundantly produced during nuclear fission and fusion.
Through mainly the process of fission, fusion, as well as neutron capture processes, they are a major contributor to the nucleosynthesis of chemical elements within stars.
The element rhenium-185 is made up of 75 protons, 110 neutrons, and 75 electrons. The element rhenium-187 is made up of 75 protons, 112 neutrons, and 75 electrons.
Thus, the correct option is D.
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1
Select the correct answer.
Which statement about the relationship between laws, hypotheses, and theories is true?
A.
Laws that remain true over an extended period of time are considered theories.
B.
A theory that holds true for a long time is considered a law.
C.
If a law is not contradicted after a lot of testing, it may be considered a hypothesis.
D.
If a hypothesis is not contradicted after a lot of testing, it may be considered a law.
Answer:
the answer is D
Explanation: