Answer:
alkali metals
Explanation:
s block elements are also called alkali metals
Solving the Sequence of an Oligopeptide From Sequence Analysis Data Analysis of the blood of a catatonic football fan revealed large concentrations of a psychotoxic octapeptide. Amino acid analysis of this octapeptide gave the following results: 2 Ala 1 Arg 1 Asp 1 Met 2 Tyr 1 Val 1 NH4 1 The following facts were observed: a. Partial acid hydrolysis of the octapeptide yielded a dipeptide of the structure C O C N H H COOH H3C CH3 CH3 C CH H3 N b. Chymotrypsin treatment of the octapeptide yielded two tetrapeptides, each containing an alanine residue. c. Trypsin treatment of one of the tetrapeptides yielded two dipeptides. d. Cyanogen bromide treatment of another sample of the same tetrapeptide yielded a tripeptide and free Tyr. e. N-terminal analysis of the other tetrapeptide gave Asn. What is the amino acid sequence of this octapeptide
Answer:
The amino sequence of an octapeptide can be determined by :
i.Amino acids present in the peptide
ii.By the behaviour shown by the treatment of these material with different biological and chemical reactions
As shown ammonium was released from the peptide,which shows that the peptide contains either Asn or Gln.
As there is presence of Asp in the amino acid analysis which indicates that the octapeptide contains Asp.
Acid hydrolysis hydrolyzes the peptide bonds which yields a Ala-Val which is the result of partial acid hydrolysis.
Chymotrypsin is on the C-terminal side of the aromatic amino acids Phe, Tyr, and Trp. The peptide has Tyr which indicates that the two present tetrapeptides after chymotrypsin treatment are fourth and eighth amino acids i-e N--Tyr-C and Tyr as the fourth amino acid and Ala-Val somewhere in the octapeptide
As Arg is only present on the C terminal side of the Trypsin cleavage therefore Arg must be the second or the sixth amino acid for the two dipeptides to form as a result of arginine treatment of a tetrapeptide
Cyanogen bromide cleaves on the C-terminal side of Met residues. For free Tyr to be produced from cyanogen bromide treatment of one of the tetrapeptides, Met must be either the third or seventh amino acid. Because Ala was present in both tetrapeptides, Ala must be either the first or fifth amino acid, present in the same tetrapeptide as Arg and Met,i-e N.-Tyr-C and Ala-Val somewhere in the octapeptide and Ala-Arg-Met as the first, second, and third or fifth, sixth, and seventh amino acids and Tyr as the fourth amino acid.
One of the tetrapeptides contains Ala-Val as its second and third amino acids and Asn as its N-terminal amino acid. Therefore two combinations are possible as below
N-Asn-Ala-Val-Tyr-Ala-Arg-Met-Tyr-C or N-Ala-Arg-Met-Tyr-Asn-Ala-Val-Tyr-C
Answer:
The amino aciid sequence of an octapeptide can be determined from the amino acids that are present in the peptide and from the results of different chemical and biological treatments.
One equivalent of ammonium was released fro the peptide, indicating that the peptide contains either Asn or Gln. The presence os Asp in the amino analysis indicates that the octapeptide contains Asn.
A) Acid hydrolysis hydrolyzes peptide bonds. The dipeptide Ala-Val is obtained by partial acid hydrolysis. The indicates that Ala-Val is present in the peptide
B) Chymotrypsin cleaves on the C-terminal side of the aromatic amino acids. Phe, Tyr, and Trp. The peptide contains only Tyr. The presence of tetrapeptides after the treatment of ohymotrypsin indicates that Tyr is the fourth and eighth amino acids.
N-Tyr-C and Tyr present as the fourth amino acid. in constrast, Ala-Val is present in the octapeptide
C) Trpsin cleaves on the C-terminal side of Arg and Lys residues. only Arg is present in the octapeptide. Arg must be the second or sixth amino acid, for two dipeptide to be formed from arginine during the treatment of one tetrapeptide.
D) Cyanogen bromide cleaves on the C-terminal side of Met residues. For free Tyr to be produced from cynogen bromide treatment of one of the tetrapeptides, Met must be either the third or seventh amino acid. Because Ala is present in both tetrapeptides, Ala must be either the first or fifth amino acid, present in the same tetrapeptide as Arg and Met.
In addition, presence of N-...-Tyr-C and Ala-Val in the octapeptide and Ala-Arg-Met as the first, second, third or fifth, sixth or seventh amino acids and Tyr as the fourth amino acid.
E) One of the tetrapides contains Asn as its N-terminal amino acid, and Ala-Val as its second and third amino acids. Two octapeptides are possible from this peptide analysis.
The amino acid sequence of the octapeptide is the following:
N-Asn-Ala-Val-Tyr-Ala-Arg-Met-Tyr-C:
N-Ala-Arg-Met-Tyr-Asn-Ala-Val-Tyr-C:
For more information visit,
https://brainly.com/question/18122741
In which direction does heat energy move? (2 points)
a
From cold objects to colder objects
b
From colder objects to warmer ones
c
From warmer objects to colder ones
d
From warm objects to warmer objects
Answer: C.
Explanation:
This is called entropy I believe. (it wouldn't let me answer before)
PLZ HELP HURRY PLZZZZZ WILL GIVE BRAINLIEST
Answer:
I think its b
Explanation:
Calculate the molarity of a solution prepared by dissolving 0.20 mol of KNO3 into enough water to make 250 mL of solution. ______ M
Answer:
0.8M
Explanation:
Given parameters:
Number of moles of KNO₃ = 0.2mol
Volume of KNO₃ = 250mL
Unknown:
Molarity of the solution = ?
Solution:
The molarity of a solution is the number of moles in a given volume of a solution;
Molarity = [tex]\frac{number of moles }{volume}[/tex]
We need to convert the given volume to L;
1000mL = 1L
250mL will give 250 x 10⁻³L = 0.25L
So;
Molarity = [tex]\frac{0.2}{0.25}[/tex] = 0.8M
Answer:
0.8 M
Explanation:
The formula is mol divided by liters. Converting 250 ml to .25 liters is important. Dividing .2 by .25 gets the answer. (I swear it’s right but it’s graded wrong so take this with a grain of salt)
what does it mean for electrons to be excited
Answer:
When an electron temporarily occupies an energy state greater than its ground state, it is in an excited state. An electron can become excited if it is given extra energy, such as if it absorbs a photon, or packet of light, or collides with a nearby atom or particle.
Explanation:
Hope this helps.
Have a good night ma´am/sir.
Be safe!
A cylinder at left with balls stacked near the bottom of the cylinder has an arrow leading to a cylinder at right cylinder with balls in a layer on the bottom of the cylinder.
How is energy related to the change of state represented by the model?
Atoms gain energy as a solid changes to a liquid.
Atoms gain energy as a solid changes to a gas.
Atoms lose energy as a solid changes to a liquid.
Atoms lose energy as a solid changes to a gas.
The energy related to the change of state represented by the model is atoms gain energy as a solid changes to a liquid. Thus option A is correct.
What is energy?Energy is defined as the quantitative property that is imparted to a body or a physical system and is visible in the performance of work as well as in the form of heat and light.
It can also be defined as ability to perform work.
There are basically nine types of energy:
Thermal energyRadiant energyNuclear energyChemical energy Electrical energyMotion energySound energyElastic energyGravitational energyThere are two more forms of energy.
Potential energyKinetic energyIn terms of atomic randomness, the gas contains atoms with extremely high kinetic energies. Atoms in the solid are only vibrating where they should be. As a result, for a gas to become a solid, some energy must be lost within the atom.
Thus, the energy related to the change of state represented by the model is atoms gain energy as a solid changes to a liquid. Thus option A is correct.
To learn more about energy, refer to the link below:
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Answer: Option A
Explanation: took the test
the sun has the same diameter as jupiter?
Translate each number into standard notation
4.52 x 10 power3
Answer:
4.52×1000=4520
Explanation:
4.52*1000=4520
15) What is the hydronium ion concentration [H3O + ] of a 0.125 M hydrocyanic acid solution with Ka = 4.9 × 10-10? The equation for the dissociation of hydrocyanic acid is: HCN(aq) + H2O(l) ⇌ H3O+(aq) + CN- (aq)
The hydronium ion concentration [H₃O⁺]=7.826 x 10⁻⁶
Further explanationIn general, the weak acid ionization reaction
HA (aq) ---> H⁺ (aq) + A⁻ (aq)
Ka's value
[tex]\large {\boxed {\bold {Ka \: = \: \frac {[H ^ +] [A ^ -]} {[HA]}}}}[/tex]
Reaction
HCN(aq) + H₂O(l) ⇌ H₃O⁺(aq) + CN⁻ (aq)
0.125
x x x
0.125-x x x
[tex]\tt Ka=\dfrac{[H_3O^+][CN^-]}{[HCN^-]}[/tex]
[tex]\tt 4.9\times 10^{-10}=\dfrac{x^2}{0.125-x}\approx \dfrac{x^2}{0.125}\\\\x^2=6.125\times 10^{-11}\\\\x=7.826\times 10^{-6}[/tex]
Identify the noble gas that has atoms with the
same number of electrons as a chloride ion in
table salt.
Answer:
Ar
Explanation:
Chlorine has an atomic number of 17. That means that it has 17 protons and 17 electrons, thus being electrically neutral. When it gains 1 electron to form the chloride ion, the total number of electrons is 17 + 1 = 18.
Argon is a noble gas with an atomic number of 18, that is, it has 18 protons and 18 electrons.}
Then Cl⁻ has the same number of electrons as Ar.
Convert 4.30×10^25 molecules of NH3 to moles please do step by step so I can Understand
Explanation:
Number of molecules: 4.30×10²⁵
We need to find out the total number of moles.
Now, as per Avogadro's law, 6.02×10²³ of anything (Avogadro's number) constitutes a unit called one mole. Just like 12 is a dozen, 6.02×10²³ is a mole.
If you were given 24 bananas and you had to find out the number of dozens, you would divide the total number of bananas (24) by the number of bananas in one dozen (12).
We do exactly the same here: divide the total number of molecules (4.30×10²⁵) by the number of molecules in one mole (6.02×10²³) to get the number of moles.
4.30×10²⁵ / 6.02×10²³ = number of moles
Solving, we get number of NH3 moles = 71.4 which is your final answer!
Hope this helps :D
Why do we assume that the color of the flame is due to the positive ion ?
Answer:
Any element placed in a flame will change its color. Atoms are made of positively charged nuclei, about which negatively charged electrons move according to the laws of quantum mechanics. Quantum mechanics constrains them to appear in various distinct patterns, called orbitals. (Orbitals are a lot like planetary orbits, but blurrier, so that you're never quite sure just where the electrons are.)
Left on their own, the electrons of an atom tend to relax into orbitals that leave the atom with the lowest possible energy--its ground state. Putting atoms into a flame, though, adds energy to the looser electrons farthest from the nucleus and pushes them into other orbitals. Eventually, these excited electrons drop back to where they ought to be, and in so doing, they release the energy they stored up as particles of light, called photons.
Explanation:
Convert 840 mL to liters ( be sure to keep the appropriate number of significant figures - also, only enter a number DO NOT INCLUDE UNITS)
Calculate the number of moles in 144 g of P. Please show your work to receive credit.
Answer:
144 g of phosphorus contain 4.65 moles.
Explanation:
Given data:
Mass of phosphorus = 144 g
Number of moles = ?
Solution:
Formula:
Number of moles = mass/ molar mass
Molar mass of phosphorus is 31 g/mol
Now we will put the values in formula.
Number of moles = 144 g/ 31 g/mol
Number of moles = 4.65 mol
Thus, 144 g of phosphorus contain 4.65 moles.
5. What could you do to convert from meters to centimeters? *
A. There is no standard way to convert these units.
B. Leave the decimal in the same position.
C. Move the decimal to the right.
D. Move the decimal to the left.
C.
centi- is essentially 10^2 of one meter.
If you had 100m, multiplying 100 by 10^2 (or 100) would give you 10000 cm.
Anions have a _______ charge and cations have a _______ charge
Explanation:
Anions have a negative charge resulting from the gain of one or more electrons to become stable.
Cations have a positive charge due to the loss of two or more electrons in order to become stable or have a noble gas configuration.
Hope this helps you
A Geiger counter used in several applications over the course of a typical day produces on the average 100 counts per second. The tube is in the form of a cylinder 5 cm in diameter by 20 cm long and is filled with a mixture of 90% argon and 10% ethanol to a pressure of 0.1 atmosphere. In the Geiger-Muller region, each output count results from the formation of about 1010 ion-electron pairs. How long will it take for one-third of the quenching gas to be used up, thus necessitating replacement of the tube
Answer:
As it is given that
[tex]activity=\lambda= 100\\[/tex]
[tex]Number~of ~counts=100/second\\[/tex]
Using formula
[tex]ln(\frac{N}{N_o})=-\lambda\cdot t\\\\[/tex]
or
[tex]-\frac{ln(\frac{N}{N_o})}{\lambda}= t\\\\[/tex]
where [tex]N=\frac{N_o}{3}[/tex]
[tex]-\frac{ln(\frac{1}{3})}{100}= t\\\\\-\frac{-1.0986}{100}=t\\\\[/tex]
[tex]\frac{1.0986}{100}=t\\1.0986\cdot 10^{-2}seconds=t\\[/tex]
What is an Ionic Bond and what types of elements are likely to form Ionic Bonds?
Answer:
ionic bonds also called electrovalent bonds areee bonds that exist two metals.It is an electrostatic attraction between positive and negative ions in a Crystal lattice.
Explanation:
examples of elements with this bond are
hydrogen chloride
copper oxide
potassium bromate
For a reversible reaction, what would a large equilibrium constant indicate?
Question 5 options:
A)
At equilibrium, there will be no reactants left because they will all have been turned into products.
B)
At equilibrium, the concentration of the reactants will be much higher than the concentration of the products.
C)
At equilibrium, the concentration of the products will be about the same as the concentration of the reactants.
D)
At equilibrium, the concentration of the products will be much higher than the concentration of the reactants.
(D) At equilibrium, the concentration of the products will be much higher than the concentration of the reactants.
Other than lowering the cost of producing coins, what could be another added benefit of changing the metals used to make coins?(hint: think of the density...why would a metal that is less dense be beneficial?)
Answer:
See explanation
Explanation:
A coin is money made from metal stuff. Common coinage metals are copper, silver, nickel etc.
One consideration in coin production is the density of the coin. A coin of less density will have lesser mass and occupy a lesser volume. This makes it easier to carry the coin around.
Coins should therefore be made of low density metals so that they can easily be carried about.
What symbol is used to separate the products from each other or the reactants from each other in a chemical reaction?
an arrow pointing to the left
an equal sign
an arrow pointing to the right
a plus sign
Answer:
a plus sign: +
Explanation:
a plus sign is used to separate one reactant or product from another
Answer:
(Chemical Formulas test)
1.Which formula contains a metal and a nonmetal?
answer:(MGO)
2.Which formula represents a covalent compound?
answer:(H2O2)
3.In the formula for water (H2O), what does the lack of a subscript after the O indicate? answer:(There is one oxygen atom in the compound.)
4.What symbol is used to separate the products from each other or the reactants from each other in a chemical reaction?answer: (A PLUS SIGHN)
5.Which option is a covalent compound?
answer:(NO2)
Explanation:
Took the Test and got 100% thank me later
50 POINTS! PLEASE HELP!A gas in a balloon at constant pressure has a volume of 120.0mL at -12.30C. What is its volume at 197.00C?
Answer:
Final volume=V₂ = 216.3 mL
Explanation:
Given data:
Initial volume = 120.0 mL
Initial temperature = -12.3 °C (-12.3 +273 = 260.7 K)
Final volume = ?
Final temperature = 197.0 °C (197+273 = 470 K)
Solution:
We will apply Charles Law to solve the problem.
According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.
Mathematical expression:
V₁/T₁ = V₂/T₂
V₁ = Initial volume
T₁ = Initial temperature
V₂ = Final volume
T₂ = Final temperature
Now we will put the values in formula.
V₁/T₁ = V₂/T₂
V₂ = V₁T₂/T₁
V₂ = 120 mL × 470 K /260.7K
V₂ = 56400 mL.K /260.7K
V₂ = 216.3 mL
Which feature is used to classify a rock based on its composition?
the origin of the rock
the texture of the rock
the types of minerals in the rock
the shapes of the crystals in the rock
Answer:
the types of minerals in the rock
Answer:
C
Explanation: I took the test and got it right (first person is right)
what is the term for an object strength of motion
Answer:
Inertia
Explanation:
Inertia is the tendency of an object to resist a change in motion. Newton's First Law of Motion is also called the law of inertia. A full aquarium is harder to move than an empty one because the law of inertia.
which metal is most likely to form more than one kind of positively charged ion
Answer:
metal atoms lose electrons to form positivity charged ions. non metal atoms gain electrons to form negatively charged ions
The table shows the average number of pounds of trash generated per person per day in the United States from 1970 to 2010. Use the statistics calculator to calculate the mean and median. Round the answers to the nearest hundredth.
Median =
Mean =
Answer: median :4.44 mean :4.11
Explanation:
i did test on Edge
You are given a glass rod that is negatively charged and a pinwheel that has a negative charge. What will happen when the glass rod is brought close to the pinwheel? Why?
Answer:
they will repel each other
Explanation:
When these two are brought close to one another they will repel each other. This is similar to what happens with magnets, when two objects share the same polarity one object will create a repulsive force upon the second object and push it away. This repellent force is caused by an electric field from the same charged electrons in the atoms of the object. Since in this case both the glass rod and the pinwheel have a negative charge they will repel each other when they come into proximity of one another.
Each axis on a graph should be:
equal
O numbered
Olabeled
vertical
A sample of gas is placed into an enclosed cylinder and fitted with a movable piston. Calculate the work (in joules) done on the gas if it is compressed from 13.43 L to 6.87 L with a pressure of 1.91 atm.
Answer:
Work done = 664.69 J
Explanation:
Given data:
Work done = ?
Initial volume = 13.43 L
Final volume = 6.87 L
Pressure = 1.91 atm
Solution:
work done = W = -PΔV
ΔV = V₂- V₁
work done = w = -P(V₂- V₁)
Now we will put the values in formula.
W = - 1 atm (6.87 L - 13.43 L)
W = - 1 atm (-6.56 L)
W = 6.56 atm.L
atm.L to joule:
6.56 atm.L × 101.325 J / 1L.atm
664.69 J
dentify the following chemical reactions as decomposition, combination/synthesis, single-displacement, double-replacement, or combustion.
(a) AgNO3(aq) + KCl(aq) → AgCl(s) + KNO3(aq)
(b) C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O(l)
(c) Cu(s) + 2 AgNO3(aq) → Cu(NO3)2(aq) + 2 Ag(s)
(d) Cu(s) + 2 AgNO3(aq) → Cu(NO3)2(aq) + 2 Ag(s)
(e) SrO(s) + SO2(g) → SrSO3(s)
Answer:
(a)Double Replacement
(b)Double Replacement
(c)Single replacement
(d)single replacement
(e) synthesis