Answer:
B. Chlorine has more than one stable isotope that occurs naturally.
D. As fluorine only has one isotope the atomic mass is identical to the mass of the isotope.
Explanation:
The reason for the difference seen between the atomic mass provided in the periodic table and the atomic mass of each element is that most naturally occurring elements have more than one isotope (isotopes are atoms that have the same atomic number but different mass numbers). This means that when we measure the atomic mass of an element, we must generally settle for the average mass of the naturally occurring mixture of isotopes.
¹⁹F is the only stable isotope of fluorine, and its abundance is 100%. Therefore, its atomic mass is identical to that of the isotope.
On the other hand, chlorine has two stable isotopes ³⁵Cl (75.77%) and ³⁷Cl (24.23%). The atomic mass of ³⁵Cl has been determined to be 34.96885 amu, and the atomic mass of ³⁷Cl has been determined to be 36.96590 amu. Thus, the average atomic mass of chlorine can be calculated as follows:
average atomic mass of natural chlorine = (0.7577)×(34.96885 amu) + (0.2423)×(36.96590 amu) = 35.45 amu
Note that in calculations involving percentages, we need to convert percentages to fractions.
There are 360 degrees in a circle. How many arcminutes will be in 86% of a circle?
Answer:
There are 18572.9 arcminutes in 86% of a circle.
Explanation:
The degrees in 86% of a circle is:
[tex] degrees = \frac{86}{100}*360 = 309.6 ^{\circ} [/tex]
Now, we need to find the number of arcminutes in 309.6°:
[tex] arcminute = \frac{59.99 arcminute}{1 degree}*309.6 degrees = 18572.9 [/tex]
Therefore, there are 18572.9 arcminutes in 86% of a circle.
I hope it helps you!
What are electrolytes?
Answer:
Electrolytes are minerals in your body that have an electric charge. They are in your blood, urine, tissues, and other body fluids. Electrolytes are important because they help. Balance the amount of water in your body
Explanation:
QUESTION 10
The stoppers were weighed directly on the balance, but liquids and powders cannot be. Explain why the use
the tare button would be especially useful for liquids and powdered substances.
Dr. Winters decides not to tell the people in his experiment about the potential risks. He
.
A) is within the limits of ethical behavior
B) is being noncompliant
C) is making an honest mistake
D) has a lot of integrity
Answer: sorry I cant help you I need the same answer
Explanation:
Answer:
b
Explanation:
What is a observation
Look at the image of the solar system,
According to Kepler, which planet travels the fastest?
Neptune
Our Solar System
O Earth
Saturn
O Jupiter
O Mercury
Neptune
Mars
Uranus
Asteroid Bilt.
The Sun
Mercury
Earth
Venus
Jupiter
Mark this and return
Save and Exit
Nex
Submit
Answer:
Mercury
Explanation:
Select the statements that correctly describe buffers.
A) A buffer is made up of a strong acid and a strong base.
B) The pH of a buffer solution does not change significantly when a small amount of acid is added.
C) The pH of a buffer solution is determined by the ratio of the concentration of acid to the concentration of base.
D) The K_a of a buffer decreases slightly when a small amount of acid is added to the buffer solution.
E) A strong acid added to the buffer solution reacts with the weak acid of the buffer.
Answer:
B) The pH of a buffer solution does not change significantly when a small amount of acid is added.
C) The pH of a buffer solution is determined by the ratio of the concentration of acid to the concentration of base.
Explanation:
Buffer solution is useful in maintaining the pH of a solution constant . It is made of a weak acid and its salt or a weak base and its salt . Ph of a buffer is given by the following relation .
pH = pKa + log [ A⁻ ] / [ HA ]
A- is a base and HA is a weak acid .
When we add acid , it reacts with A⁻ or base and gets neutralised .
When we add base , it reacts with acid HA and gets neutralised . In this way it maintains the pH of the solution .
Correct statements are as follows:
B) When a tiny amount of solvent is introduced to a buffer, the pH doesn't really alter considerably.
C) The ratio of acids to base concentration determines the pH of a phosphate buffer.
So, options B) and C) are correct.
Define pH.ph scale used in science to measure the acidity or alkalinity of an aqueous solution. pH originally stood for "potential of hydrogen." The pH of acidic solutions is lower than that of basic or alkaline solutions.
Correct statements are as follows:
B) When a tiny amount of solvent is introduced to a buffer, the pH doesn't really alter considerably.
C) The ratio of acids to base concentration determines the pH of a phosphate buffer.
So, options B) and C) are correct.
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Which of the following compounds will not possess dipole dipole interactions between its molecules?A. HBr.B. CO2.C. PH.D. NO.E. SCl.
Answer:
B. CO2
Explanation:
Because its a neutral compound hence lacks any form of dipole dipole interaction
Isotopes are atoms with the SAME number of protons, but DIFFERENT numbers of neutrons. Question 8 options: True False
Answer: The correct answer would be : True
I hope that this helps you !
Does the density of a liquid depend on its volume? Write your answer as a CER.
Answer: Yes
Explanation:
Density of a liquid depend on its volume. This is because Density is mass of liquid divided by volume.
Density is inversely proportional to volume.
As density increases, volume decreases and vice versa. The density for water is 1g/ milliliter but it changes with changes in temperature or there are impurities dissolved in it. Ice is less dense that liquid water and it's the major reason it's float because it's volume is inversely proportional to it's density.
Two particles of the element iodine are chemically bound. The two particles compose what?
Group of answer choices
a compound
a molecule
an isotope
an atom
Answer:
compound and elements.
Explanation:
CH3
/
CH3----C-----CH3
/
CH3
Spell out the full name of compound.
Answer:
A. Neopentane.
B. 2,2-dimethyl-propane.
Explanation:
Hello,
In this case, for the given compound we can spell out two possible names:
A. Neopentane: it is, because the molecule has five carbon atoms wherein there is a central one, bonded to the other four.
B. 2,2-dimethyl-propane: it is, because we find two methyl radicals at the second carbon.
Regards.
In Europe, gasoline efficiency is measured in km/L. If your car’s gas mileage is 25.0 mi/gal, how many liters of gasoline would need to buy to complete a 250 km trip to Europe? Use the following conversions: 1 km= 0.6214 mi and 1 gal = 3.78L
Answer:
[tex]V=23.5L[/tex]
Explanation:
Hello,
In this case, it is convenient to compute the car's mileage in km/L as follows:
[tex]25.0\frac{mi}{gal}*\frac{1km}{0.6214mi}*\frac{1gal}{3.78L}=10.64\frac{km}{L}[/tex]
In such a way, since the distance is measured to be 250 km, the volume requirement is:
[tex]V=\frac{250km}{10.64kg/L}\\ \\V=23.5L[/tex]
Regards.
The work needed to move a mass of 2.12 kg 47.1 m against a resistive force of 21.4 N is ___ J.
Answer:
1007.94 J
Explanation:
Work done: This can be defined as the product of force and distance, along the direction of the force. The S.I unit of work is Joules (J) .
Form the question above,
W = F×d........................... Equation 1
Where W = Work done, F = Resistive force, d = distance.
Given: F = 21.4 N, d = 47.1 m
Substitute these values into equation 1
W = 21.4(47.1)
W = 1007.94 J
Given the ion C2O4-2, what species would you expect to form with each of the following ions?
A. K+______
B. Cu2+______
C. Bi3+______
D. Pb4+______
E. NH4+______
F. H+______
Answer:
A. K₂C₂O₄ Potassium oxalate
B. CuC₂O₄ Copper oxalate
C. Bi₂(C₂O₄)₃ Bismuth (III) oxalate
D. Pb(C₂O₄)₂ Lead (IV) oxalate
E. (NH₄)₂C₂O₄ Ammonium oxalate
F. HC₂O₄⁻ Acid oxalate
Explanation:
C₂O₄⁻² → oxalate anion
This is the conjugate base from the H₂C₂O₄ which is the oxalic acid. A weak dyprotic acid that can release 2 protons.
A. 2K⁺ + C₂O₄⁻² → K₂C₂O₄ Potassium oxalate
It can be formed by the neutralization of the acid with the base
H₂C₂O₄ + 2KOH → K₂C₂O₄ + 2H₂O
B. Cu²⁺ + C₂O₄⁻² ⇄ CuC₂O₄ ↓
This is a precipitate.
C. 2Bi³⁺ + 3C₂O₄⁻² ⇄ Bi₂(C₂O₄)₃ ↓
This is a precipitate.
D. Pb⁴⁺ + 2C₂O₄⁻² ⇄ Pb(C₂O₄)₂ ↓
This is a precipitate.
E. 2NH₄⁺ + C₂O₄⁻² ⇄ (NH₄)₂C₂O₄ ↓
This is a precipitate.
F. This is the conjugate strong base, for the weak acid
H⁺ + C₂O₄⁻² ⇄ HC₂O₄⁻
HC₂O₄⁻ + H₂O ⇄ C₂O₄⁻² + H₃O⁺ Ka
HC₂O₄⁻ + H₂O ⇄ H₂C₂O₄ + OH⁻ Kb
HC₂O₄⁻ is an amphoteric compound
A. K₂C₂O₄ →Potassium oxalate
B. CuC₂O₄ →Copper oxalate
C. Bi₂(C₂O₄)₃ →Bismuth (III) oxalate
D. Pb(C₂O₄)₂ →Lead (IV) oxalate
E. (NH₄)₂C₂O₄ →Ammonium oxalate
F. HC₂O₄⁻ →Acid oxalate
Given:
C₂O₄⁻² → oxalate anionIt is the conjugate base from the H₂C₂O₄ which is the oxalic acid. A weak diprotic acid that can release 2 protons.
The reactions involved in this are:
A. 2K⁺ + C₂O₄⁻² → K₂C₂O₄
B. Cu²⁺ + C₂O₄⁻² ⇄ CuC₂O₄ ↓
C. 2Bi³⁺ + 3C₂O₄⁻² ⇄ Bi₂(C₂O₄)₃ ↓
D. Pb⁴⁺ + 2C₂O₄⁻² ⇄ Pb(C₂O₄)₂ ↓
E. 2NH₄⁺ + C₂O₄⁻² ⇄ (NH₄)₂C₂O₄ ↓
↓- This symbol denotes the precipitate formation.
F. H⁺ + C₂O₄⁻² ⇄ HC₂O₄⁻
This is the conjugate strong base, for the weak acid.HC₂O₄⁻ is an amphoteric compound.
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100 POINTS & BRAINLIEST !!!! PLEASE HELP three qualitative and three quantitative observations, and one inference
Answer: 3 qualitative: the word pharmacology is written in blue, the stairs are gray, the tile on the first floor is yellow. 3 quantitative: there are four people wearing yellow, there are Four pink boxes, there are two floors.
Inference: there are many people performing experiments so it’s a lab.
Explanation:
Answer:
Qualitive - The bars are yellow, The floor is green, and the floor has pharmacology on it.
Quantitative - There are 8 support bars, There is 3 gray coats, and there is 27 pills that I can see on that picture.
Inference - There are many people doing experiments because the word pharmacology is on the floor.
Explanation:
This picture tells you that pharmacology is a form of study of medicine and drugs.
ILL GIVE YOU BRAINLIST !!! HAVE TO GET IT RIGHT !!
1.
Explain.
Identify Which are the quantitative data in the example above?
Answer: The 3rd and 6th bullet point is the quantitative data.
Explanation: Quantitative data is expressed by NUMBERS and Qualitative data is expressed by WORDS. The 3rd and 6th one is correct because they both use numbers to compare how much time hummingbirds spent feeding on nectar.
How do vapors and gases differ
Answer:
Difference between Vapor and Gas
Usually, a vapour phase consists of a phase with two different substances at room temperature, whereas a gas phase consists of a single substance at a defined thermodynamic range, at room temperature
Explanation:
Which of the following is NOT a "weak" interaction?
a. hydrogen bonds b. van der Waals forces c. disulfide bonds d. ionic interactions e. hydrophobic interactions
Answer:
D.ionic interaction is a strong interaction
When atoms come close enough to one another, an ionic connection is created. Atoms can interact with one another ionically, and this distance is greater than the bonding distance. Therefore, option D is correct.
What is ionic interaction ?The main interaction taking place in ionic compounds is ionic bonding, a form of chemical bonding that includes the electrostatic attraction between two atoms or ions with dramatically differing electronegativities.
Ions with opposing charges are drawn to one another through ion-ion interactions. They are also known as ionic bonds, because they are what keep ionic compounds together. opposing charges attract each other whereas like charges repel each other.
The whole transfer of valence electrons between atoms is referred to as an ionic bond. It is a kind of chemical connection that produces two ions with opposing charges. In ionic bonding, the nonmetal receives the electrons to become a negatively charged anion while the metal gives them up to become a positively charged cation.
Thus, option D is correct.
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What causes blood cells to shrink?
6. What effect does an increase in blood hydrogen ion levels have on the pH of the blood?
Answer: the two parameters change inversely; as hydrogen ion concentration increases, pH falls. due to the logarithmic relationship, a large change in hydrogen ion concentration is actually a small change in pH. For example, doubling the hydrogen ion concentration causes pH to fall by just 0.3.
If hydroxide is added to an amino acid, how will this affect the charge on the amino acid?
Answer:
The amino acid will become more negatively charged
Explanation:
Amino acids are organic compounds containing the positive amine (-NH₂) group which is the basic group, and the negative carboxylic (-COOH) group, which is the acidic group. Because they contain both acidic and basic groups with a positive and negative charge that do not contain an overall electric charge, they are known as zwitterions. They are the smallest units of a protein molecule.
When a hydroxide group is added to an amino acid, the PH is increased, and the hydrogen ion on the amine (NH₃+) is removed, making the compound to have an overall negative charge, hence it is no longer a zwitterion.
[tex]\chemfig{N H_3^+-R-CH-COO^- + OH^- \longrightarrow \chemfig{N H_2-R-CH-COO^- + H_2O[/tex]
notice that the amino group has a net negative charge on the product side of the reaction
The addition of hydroxide to an amino acid affects the charge on the amino acid as it will become more negatively charged.
It will become more negatively charged.
Amino AcidWhen placed in an electromagnetic field, the physical attribute of matter known as electric charge causes it to experience a force.
A positive or negative electric charge can exist. Amino acids are chemical molecules made up of amino and carboxylate. Hydroxide is a polyatomic ion made up of two elements: oxygen and hydrogen.
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During studies of the following reaction (i), a chemical engineer measured a less-than-expected yield of N2 and discovered that the following side reaction (ii) occurs. (i) N2O4(l) 2 N2H4(l) 3 N2(g) 4 H2O(g) (ii) 2 N2O4(l) N2H4(l) 6 NO(g) 2 H2O(g) In one experiment 12.7 g of NO formed when 101.1 g of each reactant was used. What is the highest percent yield of N2 that can be expected
Answer:
Maximum expected yield = 87.2%
Explanation:
Equations of reactions:
Main reaction: N₂O₄(l) + 2N₂H₄(l) ---> 3N₂(g) + 4H₂O(g)
Side reaction: 2N₂O₄(l) + N₂H₄(l) ----> 6NO(g) + 2H₂O(g)
Molar mass of N₂O₄ = 92 g/mol; molar mass of N₂H₄ = 32 g/mol; molar mass of N₂ = 28 g/mol; molar mass of of NO = 30 g/mol; molar mass of water = 18 g/mol
In the main reaction, 92 g of N₂O₄ reacts with 2 * 32 g of N₂H₄ to produce 3 * 14 g of N₂.
101.1 g of N₂O₄ will react with 2 * 32 * 101.1 / 92 g of N₂H₄ = 70.33 g of N₂H₄
N₂O₄ is the limiting reactant
101.1 g of N₂O₄ will react to produce 3 * 14 * 101.1 / 92 g of N₂ = 46.15 g of N₂
In the side reaction, (6 * 30 g) of NO is produced from (2 * 92 g) of N₂O₄ and 32 g of N₂H₄
12.7 g of N₂O₄ will be produced from ( 2 * 92 * 12.7/180 g) of N₂O₄ and (32 * 12.7/180) g of N₂H₄ to produce
mass of N₂O₄ used = 12.98 g
mass of N₂H₄ used = 2.26 g
mass of N₂O₄ left for main reaction = 101.1 - 12.98 = 88.12 g
mass of N₂H₄ left for main reaction = 101.1 - 2.26 = 98.84 g
In the main reaction, 92 g of N₂O₄ reacts with 2 * 32 g of N₂H₄ to produce 3 * 14 g of N₂
88.12 g of N₂O₄ will react with 2 * 32 * 88.12 / 92 g of N₂H₄ = 61.30 g of N₂H₄
N₂O₄ is the limiting reactant.
88.12 g of N₂O₄ will to react produce 3 * 14 * 88.12 / 92 g of N₂ = 40.23 g of N₂
Percentage yield = (theoretical yield/actual yield) * 100%
Percentage yield = (40.23/46.15) * 100% = 87.2%
Therefore, maximum expected yield = 87.2%
Differentiate between a pure substance and a mixture and provide examples
Explanation:
pure substances are those substances which are made up of one elements
mixture that those substances which are made by more than two or three elements
Answer:
Brainliest is appreciated
Explanation:
Substances which have a specific composition and cannot be separated into any constituents are called pure substances. Pure substances are further divided into elements and compounds. The combination of two or more pure substances is called a mixture. Mixtures can be classified into two types viz. heterogeneous and homogeneous mixtures.
EXAMPLES
pure substance
gold, pure water, hydrogen gas
mixture substance
oil and water, sand and sugar
(3.0 x 10^8) / (5.76 x 10^14 s-1)
Answer:
521 nm
Explanation:
The following data were obtained from the question:
Frequency (f) = 5.76×10¹⁴ s¯¹
Wavelength (λ) =?
Velocity (v) , wavelength (λ) and frequency of a wave are related according to the following equation:
Velocity (v) = wavelength (λ) × frequency (f)
v = λf
With the above equation, we can obtain the wavelength of the photon of the green light as follow:
Frequency (f) = 5.76×10¹⁴ s¯¹
Velocity of light (v) = 3×10⁸ m/s
Wavelength (λ) =?
v = λf
3×10⁸ = λ × 5.76×10¹⁴
Divide both side by 5.76×10¹⁴
λ = 3×10⁸ / 5.76×10¹⁴
λ = 5.21×10¯⁷ m
Finally, we shall convert 5.21×10¯⁷ m to nanometer (nm).
This can be obtained as follow:
1 m = 1×10⁹ nm
Therefore,
5.21×10¯⁷ m = 5.21×10¯⁷ × 1×10⁹
5.21×10¯⁷ m = 521 nm
Therefore, the wavelength (λ) of the photon of the green light is 521 nm
The boiling point of another member of this homologous series was found to be 309 KK. What is the likely molecular formula for this compound?
Answer: Pentane C5H12
Explanation:
The boiling point of a substance is simply defined as the temperature whereby a liquid's vapor pressure is equal to the pressure that is surrounding the liquid and hence, the liquid will changes into vapor.
The likely molecular formula for this compound is Pentane i.e C5H12 due to the fact that its boiling point is between Butane with formula C4H10 and Hexane with formula C6H14 boiling points.
The molecular formula of the of the substance is [tex]\bold {C_5H_1_0}[/tex] (pentane).
Boiling point:
It is the temperature at which liquid's vapor pressure is equal to the pressure that is surrounding the liquid and hence, the liquid start to into vaporize.
The boiling point of the given compound is 309 K which is between Butane and Hexane.
Therefore, the molecular formula of the of the substance is [tex]\bold {C_5H_1_0}[/tex] (pentane).
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Scientists are studying different jackets made for extremely cold, snowy weather. They are trying to find jackets
that are warm but also thin enough to allow for natural bodily movement.
Which question could the scientists answer scientifically?
Which jacket's color looks the best?
Which jacket traps the most heat?
Would warm and thin jackets cost less?
Which jacket seems the most professional?
jp
Answer:
Which jacket traps the most heat.
Explanation:
I took the test
Answer:
B. Which jacket traps the most heat?
Explanation:
Just got it right on Edg
Question 2
5 pts
80) Multiply 6.4 x 10-3 times 8.0 x 10' and express the answer in scientific notation.
O 5.1 x 10-21
O 5.1 x 10-3
O 5.1x 103
O 5.1x 104
0 5.1 x 105
5 pts
Answer:
5.1 x 10⁻¹
Explanation:
Given:
6.4 × 10⁻³ × 8.0 × 10¹
Find:
Value of equation
Computation:
6.4 × 10⁻³ × 8.0 x 10¹
[6.4 × 8.0] × [10⁻³ × 10¹]
[51.2] × [10⁻²]
5.12 x 10⁻¹
5.1 x 10⁻¹ (Approx)
A sample of mass 6.814 grams is added to another sample weighing 0.08753 grams.
The subsequent mixture is then divided into exactly 3 equal parts. One of those parts has the yield multiplied by 7.6335 times; what is the final mass?
Answer:
17.5609grams
Explanation:
According to the question, a sample of mass 6.814 grams is added to another sample weighing 0.08753 grams i.e.
= 6.814 + 0.08753
= 6.90153 grams
The result of this mixture i.e. 6.90153 grams is divided into three equal parts i.e.
= 6.90153 ÷ 3
= 2.30051 grams
This means that each equal part weighs 2.30051 grams
One of the yield (2.30051 grams) is multiplied by 7.6335 times i.e.
= 2.30051 × 7.6335
= 17.56094309
Hence, the final mass is 17.5609grams
Suppose that at 9:00 A.M. the temperature of a room is 18°C, and at noon it is 24°C. What was the increase in temperature?____________________________
Answer:what’s the answer
Explanation: