which of the following is the unit of surface tension?
Answer:
it should be N/m or newton per meter.
Determine the end (final) value of n in a hydrogen atom transition, if the electron starts in and the atom emits a photon of light with a wavelength of 486 nm. Group of answer choices
Complete Question
Determine the end (final) value of n in a hydrogen atom transition, if the electron starts in n=4 and the atom emits a photon of light with a wavelength of 486 nm. Group of answer choices
Answer:
[tex]n=2[/tex]
Explanation:
From the question we are told that:
Wavelength [tex]\lambda=486nm=>486*10^{-9}[/tex]
Generally the equation for Atom Transition is mathematically given by
[tex]\frac{1}{\lambda}=R_{\infty }(\frac{1}{n_1^2}-\frac{1}{n_2^2})[/tex]
Where
Rydberg constant [tex]R_{\infty}=1.097*10^7[/tex]
Therefore
[tex]\frac{1}{486*10^{-9}}=1.097*10^7*(\frac{1}{n_1^2}-\frac{1}{4^2})[/tex]
[tex](\frac{1}{n_1^2}-\frac{1}{4^2})=\frac{1}{486*10^{-9}*1.097*10^7}[/tex]
[tex]n_1^2=3.98[/tex]
[tex]n=1.99[/tex]
[tex]n=2[/tex]
Using the Rydberg formula, the final state of the electron is n=2.
Using the Rydberg formula;
1/λ = R(1/nf^2 - 1/ni^2)
Where;
λ = wavelength
nf = final state
ni = initial state
R = Rydberg constant
When λ = 486 × 10^-9 m and ni = 4, R = 1.097 × 10^7 m-1
1/486 × 10^-9 = 1.097 × 10^7(1/nf^2 - 1/4^2)
0.188 = 1/nf^2 - 0.0625
1/nf^2 = 0.188 + 0.0625
nf = 2
Missing parts;
Determine the end (final) value of n in the hydrogen atom transition, if electron starts in n-4 and the atom emits a photon of light with a wavelength of 486.
Learn more: https://brainly.com/question/14281129
explain why the melting point of a solid is equal to the freezing point of it's liquid.
Explanation:
Because melting point and freezing point describe the same transition of matter, in this case from liquid to solid (freezing) or equivalently, from solid to liquid (melting). It is stuck on 0 ∘C during the entire melting or freezing process. None except melting is when you heat up and freezing when you cool down.hope it helps.stay safe healthy and happy.
4. Draw conclusions: How is the periodic table organized?
Answer:
.
Elements are arranged from left to right and top to bottom in the order of their increasing atomic numbers. Thus,
Elements in the same group will have the same valence electron configuration and hence, similar chemical properties.
Whereas, elements in the same period will have an increasing order of valence electrons. Therefore, as the energy level of the atom increases, the number of energy sub-levels per energy level increases.
The first 94 elements of the periodic table are naturally occurring, while the rest from 95 to 118 have only been synthesized in laboratories or nuclear reactors.
The modern periodic table, the one we use now, is a new and improved version of certain models put forth by scientists in the 19th and 20th century. Dimitri Mendeleev put forward his periodic table based on the findings of some scientists before him like John Newlands and Antoine-Laurent de Lavoisier. However, Mendeleev is given sole credit for his development of the periodic table.
You used a variety of media with a NaCl concentration ranging from 0.5% to 15%. Which of these media would have the lowest water activity?
a. 0.5% NaCl
b. 15% NaCl
c. 10% NaCl
d. 5% NaCl
Answer:
Explanation:
B
Wine goes bad soon after opening because the ethanol dissolved in it reacts with oxygen gas to form water and aqueous acetic acid , the main ingredient in vinegar. Calculate the moles of acetic acid produced by the reaction of of ethanol. Be sure your answer has a unit symbol, if necessary, and round it to significant digits.
Answer:
The answer is "It takes 1,70 mol of ethanol".
Explanation:
To make acetic acid, we must first write the balanced reaction that occurs of ethanol with oxygen
The response is balanced:
[tex]CH_3CH_2OH+O_2\to CH_3COOH+H_2O[/tex]
1 mol of ethanol creates 1 mol of According the equilibrium Ethanol moles, therefore, required 1.70 mol of water = 1.70 mol
Please help me ASAP I’ll mark Brainly
Answer:
1. Vacuole
2. chloroplast
3. Nucleus
4. Plasma membrane - cell membrane
5. Vacuole (same as #1 ?) could be vesicle
Explanation:
How many protons are in Oxygen-18 and how many neutrons are in Copper-65? Please include steps for solving both!
Answer: There are 8 protons in oxygen-18 and 36 neutrons in copper-65.
Explanation:
An atom contains three sub-atomic particles, that is, protons, neutrons and electrons.
The atomic number is the total number of protons present in an atom. For oxygen-18, the atomic mass is 18.
Atomic mass is the sum of total number of protons and electrons present in an atom. As the atomic number of an oxygen atom is 8 so the number of protons present in oxygen-18 is 8.
The atomic mass of copper is 65 and for a copper atom, the atomic number is 29. Hence, the number of neutrons for copper-65 is as follows.
Atomic mass = no. of protons + no. of neutrons
65 = 29 + no. of neutrons
no. of neutrons = 65 - 29 = 36
Thus, we can conclude that there are 8 protons in oxygen-18 and 36 neutrons in copper-65.
The chemical formula is different from the empirical formula in
Answer:be careful and relax
Explanation:
Answer:
Hahaha be careful and relax
What kind of light would an electron experiencing n=4 to n=2 drop emit?
Hi there!
[tex]\large\boxed{\text{Visible Light.}}[/tex]
According to the diagram and the arrows, a drop from level 4 (n = 4) to level 2 (n = 2) produces orange visible light.
[tex]\red\large{{}}[/tex]
Ammonia and oxygen react to form nitrogen monoxide and water. Construct your own balanced equation to determine the amount of NO and H2O that would form when 2.78 mol NH3 and 5.19 mol O2 react.
Answer:
The amount of NO formed s 2.78 moles or 83.4 grams
The amount of H2O formed is 4.17 moles or 75.1 grams
Explanation:
Step 1: Data given
Ammonia = NH3
Oxygen = O2
nitrogen monoxide = NO
water = H2O
Number of moles NH3 = 2.78 moles
Number of O2 = 5.19 moles
Step 2: The balanced reaction
4NH3 + 5O2 → 4NO + 6H2O
Step 3: Calculate moles of products
For 4 moles NH3 we need 5 moles O2 to produce 4 moles NO and 6 moles H2O
NH3 is the limiting reactant
All the NH3 will react. There will be 0 moles of NH3 left
For 4 moles NH3 we need 5 moles O2
For 2.78 moles NH3 we need 5/4 * 2.78 = 3.475 moles
There will be left 5.19 - 3.475 = 1.715 moles O2
For 4 moles NH3 we need 5 moles O2 to produce 4 moles NO and 6 moles H2O
For 2.78 moles NH3 we'll have 2.78 moles NO and 6/4 * 2.78 = 4.17 moles H2O
Step 4: Calculate mass of NO and H2O
Mass = moles * molar mass
Mass NO = 2.78 moles * 30.01 g/mol
Mass NO = 83.43 grams
Mass H2O = 4.17 moles * 18.02 g/mol
Mass H2O = 75.14 grams
The amount of NO formed s 2.78 moles or 83.4 grams
The amount of H2O formed is 4.17 moles or 75.1 grams
The number 0.0007270 is larger than the number 5.7 × 10–3.
Answer:
Yes
Explanation:
=5.7×10-3
=5.7×7=39.9
=0.0007270 greater than 5.7× 10-3
OR
=5.7×10
=57-3
=54
So it is greater number
According to the Arrhenius equation, changing which factors will affect the
rate constant?
A. Temperature and the ideal gas constant
B. The activation energy and the constant A
C. The constant A and the temperature
D. Temperature and activation energy
Answer:
e−(Ea/RT): the fraction of the molecules present in a gas which have energies equal to or in excess of activation energy at a particular temperature
Answer:
D. Temperature and activation energy is the correct answer
Explanation:
^_^
g Arrange the following compounds in order of acidity (highest to lowest): H2O, H3O , HCl A. CH3COOH > HCl > H2O B. H2O > CH3COOH > HCl C. HCl > H2O > CH3COOH D. HCl > CH3COOH > H2O
Answer:
Arrange the following compounds in order of acidity (highest to lowest): H2O, CH3COOH , HCl
A. CH3COOH > HCl > H2O
B. H2O > CH3COOH > HCl
C. HCl > H2O > CH3COOH
D. HCl > CH3COOH > H2O
Explanation:
The given substances are acetic acid, hydrochloric acid, and water.
Since HCl is a strong acid and it undergoes complete ionization.
CH3COOH acetic acid is a weak acid and it undergoes partial dissociation in water.
Pure water is a neutral substance.
Hence, the order of acidity is shown below:
HCl > CH3COOH > H2O.
Among the given options, option D is the correct answer.
The following physical constants are for water, H2O.
The specific heat capacity of the solid = 2.09 J/g oC
The specific heat capacity of the liquid = 4.18 J/g oC
The specific heat capacity of the vapor = 2.09 J/g oC
∆Hfus = 6.02 kJ/mol; ∆Hvap = 40.7 kJ/mol Freezing point = 0.0oC; Boiling point = 100.0oC
How much heat(in kJ) is required to warm 10.0 grams of ice at -5.0oC to a temperature of 70.0oC?
Answer:
[tex]Q\approx6.4~kJ[/tex]
Explanation:
Quantity of heat required by 10 gram of ice initially warm it from -5°C to 0°C:
[tex]Q_1=m.C_s.\Delta T[/tex]
here;
mass, m = 10 g
specific heat capacity of ice, [tex]C_s=2.09~J.g^{-1}.^{\circ}C^{-1}[/tex]
change in temperature, [tex]\Delta T=(5-0)=5^{o}C[/tex]
[tex]Q_1=10\times2.09\times 5[/tex]
[tex]Q_1=104.5~J[/tex]
Amount of heat required to melt the ice at 0°C:
[tex]Q_2=m.\Delta H_{fus}[/tex]
where, [tex]\Delta H_{fus}=6020~J/mol[/tex]
we know that no. of moles is = (wt. in gram) [tex]\div[/tex] (molecular mass)
[tex]Q_2=\frac{10}{18} \times 6020[/tex]
[tex]Q_2=3344.44~J[/tex]
Now, the heat required to bring the water to 70°C from 0°C:
[tex]Q_3=m.C_L.\Delta T[/tex]
specific heat of water, [tex]C_L=4.18~J/g/^oC[/tex]
change in temperature, [tex]\Delta T=(70-0)=70^oC[/tex]
[tex]Q_3=10\times 4.18\times 70[/tex]
[tex]Q_3=2926~J[/tex]
Therefore the total heat required to warm 10.0 grams of ice at -5.0°C to a temperature of 70.0°C:
[tex]Q=Q_1+Q_2+Q_3[/tex]
[tex]Q=104.5+3344.44+2926[/tex]
[tex]Q=6374.94~J[/tex]
[tex]Q\approx6.4~kJ[/tex]
Balance the chemical equation below using the smallest possible whole number stoichiometric coefficients.
P4(s) + NaOH(aq) + H2O(l) -> Ph3(g) + Na2HPO3(aq)
Answer:
I used a,b c, d in the equation as substituted coefficients to find the unknown for each element of P, Na, O, H, and I got
P4(s) + 4NaOH(aq) + 2H20(l)---->2Ph3 +2Na2HPO3(aq).
which I think should be the answer.
the ability of organism to sense changes in its body is an example of
Answer:
the ability of organism to sense changes in its body is an example of responsiveness.Hope it is helpful to you
What is the difference between conjugate acid-base pair?
a. a H atom. c. a mole water
b. a H+ ion d. a OH– ion
Answer:
b. a H+ ion
Explanation:
The concept of conjugate acid-base pair is related to Bronsted-Lowry acid-base theory and according to this theory, acid is a proton acceptor.
In short,
conjugate base is formed when an acid donates a proton.
conjugate acid is formed when a base accepts a proton.
An unidentified gas is determined to be 24.0% carbon and 76% fluorine by mass. What is the empirical formula of this gas
Answer:
CF₂
Explanation:
Let's assume we have 100 g of the gas. If that were the case we'd have
24 g of C76 g of FNow we convert both masses into moles, using their respective molar mass:
24 g C ÷ 12 g/mol = 2 mol C76 g F ÷ 19 g/mol = 4 mol FWe can express those results as C₂F₄.
To determine the empirical formula we reduce those coefficients to the lowest possible integers, leaving us with CF₂.
Rank the following substances/solutions in order of lowest boiling point to highest boiling point where 1 has the lowest boiling point and 5 has the highest boiling point. pure water; 1.0 m NaCl; 0.5 m KBr, 0.75 m CaCl2; 1.5 m glucose (C6H12O6)
Answer:
1) pure water
2) 0.75 m CaCl2
3) 1.0 m NaCl
4) 0.5 m KBr
5) 1.5 m glucose (C6H12O6)
Explanation:
Boiling point elevation is a colligative property. Coligative properties are properties that depend on the amount of solute present in the system. The boiling point of solvents increase due to the presence of solutes.
The boiling point elevation depends on the number of particles the solute forms in solution and the molality of the solute. The more the number of particles formed by the solute and the greater the molality of the solute, the greater the magnitude of boiling point elevation.
The order of decreasing hoping point elevation is;
1) 0.75 m CaCl2
2) 1.0 m NaCl
3) 0.5 m KBr
4) 1.5 m glucose (C6H12O6)
a laser emits light with a frequency of 4.69 x 10 to the 14th power s - 1 calculate the wavelength of this light.
Answer:
6.40x10^-7
Explanation:
answer with work is attached.
43 mg = [?]g
A. 0.043 g
B. 4.3 g
C. 4300 g
D. 43,000 g
Answer:
Option A (0.043 g) is the correct answer.
Explanation:
Given:
= 43 mg
As we know,
[tex]1 \ mg = \frac{1}{1000} \ g[/tex]
then,
⇒ [tex]43 \ mg = \frac{43}{1000} \ g[/tex]
[tex]= 0.043 \ g[/tex]
Thus, the above is the correct alternative.
How many atoms are in each elemental sample?
16.8 g Sr
26.5 g Fe
8.94 g Bi
40.0 g P
Explanation:
The number of atoms in 1mol of every element can be represented by Avogadro's number, which is [tex]6.022*10^{23}[/tex].
Knowing this, now we can find the atoms in each of these molecules!
[tex]16.8gSr*\frac{1molSr}{87.62gSr} *\frac{6.022*10^{23}atomsSr}{1molSr} =[/tex]
1.15*10^23 atoms of Sr
[tex]26.5gFe*\frac{1molFe}{55.85gFe} *\frac{6.022*10^{23}atomsFe}{1molFe} =[/tex]
2.86*10^23 atoms of Fe
[tex]8.94gBi*\frac{1molBi}{208.98gBi} *\frac{6.022*10^{23}atomsBi}{1molBi} =[/tex]
2.58*10^22 atoms of Bi
[tex]40.0gP*\frac{1molP}{30.97gP} *\frac{6.022*10^{23}atomsP}{1molP}=[/tex]
7.78*10^23 atoms of P
A student performs an experiment similar to Experiment 1 using hydrochloric acid (HCl) and potassium hydroxide (KOH). The mass of the hydrochloric acid solution is 250.000 g. After combining the HCl and KOH, the final combined mass is 400.000 g. Given what you have learned about the conservation of mass in this experiment, what must have been the mass of the KOH solution
Answer:
150.000 g
Explanation:
The law of conservation of mass states that the mass of reactants and products of a reaction must be equal to one another.
In other words, for this case:
Mass of KOH + Mass of HCl = Mass of ProductsWe are given all required data to calculate the mass of the KOH solution:
Mass of KOH + 250.000 g = 400.000 gMass of KOH = 150.000 gOne of the purposes of this lab is to determine the order of the reaction with respect to the Allura Red dye by creating first and second-order graphs for all four trials. The correct order of the reaction is the one where the slopes of the graphs for the four trials are roughly the same. Why is this important when choosing the order of the reaction
Answer: Hello the options related to your question are attached below
The slope is related to the rate constant so all four trials should have the same slope since the reactions are all the same ( Option C )
Explanation:
It is important when choosing the order of the reaction because the concentration of the bleaches used in the four trials are in excess hence their slopes have to be roughly the same and also because the reactions are similar and they where done at the same temperature, hence the slope of the first and second-order graphs will be the same.
Please please help help please
Which of the following molecules can be used in catabolic reactions to generate the carbon backbones required for gluconeogenesis?
a. glutathione, a short peptide containing glutamate, serine and histidine
b. butyrate, a short chain fatty acid
c. fructose, a monosaccharide
d. starch, a polysaccharide
Answer:
The correct option is A
Explanation:
Some amino acids, called glucogenic amino acids, when catabolized convert there carbon backbones to tricarboxylic acid (TCA) cycle intermediates. These intermediates can be subsequently metabolized into carbon dioxide and water with the release of ATP or the formation of glucose (known as gluconeogenesis.
All amino acids (with the exception of leucine and lysine) are glucogenic and can thus generate the carbon backbones required for gluconeogenesis. Thus, the correct option is a.
Acetoacetyl-ACP is formed as an intermediate during fatty acid biosynthesis. The CO2 used to synthesize malonyl-CoA is lost. Would this help make the reaction more or less energetically favorable
Answer:
This would make the reaction more energetically favourable
Explanation:
Fatty acid synthesis starts with the carboxylation of acetyl CoA to malonyl CoA. This irreversible reaction is the committed step in fatty acid synthesis. The synthesis of malonyl CoA is catalyzed by acetyl CoA carboxylase, which contains a biotin prosthetic group.
A student dropped a pea size amount of K2CO3 into a solution of HCl(aq). He observed the formation of gas bubbles and collected the gas into another test tube. The student performed a splint test and observed that the splint was extingished when he placed the splint into the test tube of the gas. What can be said about the results of this students experiment?
a. The student completed the experiment correctly and there were no errors in the experiment.
b. The experiment was performed incorrectly. K2CO3 doesn't react with HCl. Therefore, the student picked up the wrong compound when conducting the experiment.
c. The student performed the splint test incorrectly. He should of observed the splint flare up when the splint was placed in the test tube.
d. The student performed the splint test incorrectly. He should of observed a popping sound when the splint was placed in the test tube.
Answer:
The student completed the experiment correctly and there were no errors in the experiment.
Explanation:
When a pea size amount of K2CO3 is dropped into a solution of HCl, the following reaction occurs;
K2CO3(s) + 2HCl(aq) ----> 2KCl(aq) + CO2(g) + H2O(l)
The gas CO2 does not support burning hence, when the student performed a splint test and observed that the splint was extinguished when he placed the splint into the test tube of the gas.
Hence, the experiment was properly conducted and the student completed the experiment correctly and there were no errors in the experiment.
Calculate the displacement (the total volume of the cylinder through which the piston move) of a 5.70L automobile engine in cubic inches, (1inch=2.54cm)
Answer:
348 inches³
Explanation:
From our previous knowledge of units conversion:
We know that 1000 cm³ makes 1 Liter.
Thus, for a 5.70 L automobile engine in cubic meters will be:
= 5.70 × 1000 cm³
= 5700 cm³
Now, the displacement of the automobile in cubic inches provided that 1 inch = 2.534 cm is:
⇒ 5700× (1/ (2.54)³) in³
= 5700×0.0610 in³
= 347.7 in³
≅ 348 inches³