Answer:
[tex]\boxed{\text{10.81 u}}[/tex]
Explanation:
The atomic mass of B is the weighted average of the atomic masses of its isotopes.
We multiply the atomic mass of each isotope by a number representing its relative importance (i.e., its percent of the total).
Set up a table for easy calculation:
[tex]\begin{array}{ccccr}\textbf{Atom} & \textbf{Mass/u} &\textbf{Percent} & \textbf{Calculation}& \textbf{Result}\\^{10}\text{B}& 10.01 & 19.91 & 10.01 \times 0.1991 & 1.99\\^{11}\text{B}& 11.01 & 80.09 & 11.01 \times 0.8009 & 8.82 \\& & & \text{TOTAL} = &\textbf{10.81}\\\end{array}[/tex]
The average atomic mass of B is [tex]\boxed{\textbf{10.81 u}}[/tex].
Answer:
10.81u
Explanation:
I just did the test
In the reaction of sodium with bromine, explain which atom is reduced.
I need you to show ALL the steps because I don't understand.
Answer:
The reduced atom is Br.
Explanation:
The oxidation-reduction reaction contains a reductant and an oxidant (oxidizing agent). The oxidation process is the process in which electrons are lost and produce positively charged ions. The reduction process is the process in which electrons is gained and negatively charge ions are produced. In the reaction of chlorine with calcium:2Na + Br₂ → 2NaBr,
Na loses 1 electrons and is oxidized to Na⁺. (Na → Na⁺ + e).
Br₂ gains 2 electrons and is reduced to 2Br⁻. (Br₂ + 2e → 2Br⁻).
So, the reduced atom is Br.
Rutherfordium-257 was synthesized by bombarding Cf-249 with C-12. Write a nuclear equation for this reaction.
Final answer:
The nuclear equation for the synthesis of rutherfordium-257 by bombarding californium-249 with carbon-12 is 24998Cf + 126C → 257104Rf + 410n. It shows the reactants, products, and the conservation of mass and atomic numbers in the reaction.
Explanation:
The student is asking for a nuclear equation for the synthesis of rutherfordium-257, which is created by bombarding californium-249 (Cf-249) with carbon-12 (C-12). The balanced nuclear equation takes into account the conservation of mass and atomic numbers. The californium-249, which has an atomic number of 98 and a mass number of 249, reacts with carbon-12, which has an atomic number of 6 and a mass number of 12.
The equation is:
24998Cf + 126C → 257104Rf + 410n
In this reaction, rutherfordium-257 has an atomic number of 104 and a mass number of 257. To conserve the mass number and atomic numbers on both sides of the equation, we need to add four free neutrons (n) with a mass number of 1 and an atomic number of 0 to the products side. This completes the balanced nuclear equation for the formation of rutherfordium-257.
We could avoid a large increase in temperature if greenhouse emissions peaked by the year of ?
To curb the increase in Earth's temperature due to greenhouse gases, we need to reach 'net zero' carbon emissions by 2050 or sooner. The problem arises largely from burning fossil fuels and deforestation, leading to increased CO2 in the atmosphere. Continued trajectory could double Earth's CO2 levels from pre-industrial times by the end of the century.
Explanation:To avoid a large increase in temperature due to greenhouse gas emissions, it is crucial that these emissions peak as soon as possible. According to the Union of Concerned Scientists, we should aim for 'net zero' carbon emissions by 2050 or even sooner. This would mean that no more carbon enters the atmosphere than is removed.
Greenhouse gases, primarily carbon dioxide, are largely a result of burning fossil fuels, such as coal and oil. Alongside this, the destruction of tropical forests which absorb CO2 from the atmosphere exacerbates the problem.
If this trajectory continues, Earth's CO2 levels are predicted to double from pre-industrial levels by the end of this century, leading to potentially catastrophic climactic changes. Hence, mitigation strategies to stabilize carbon emissions constitute a major part of our global strategy towards climate change.
Learn more about Greenhouse Gas Emissions here:https://brainly.com/question/34902503
#SPJ12
Distinguish between a solution in general and an aqueous solution
Answer:
What distinguish a solution in general from an aqueous solution is the solvent. A solution in general may contain any solvent, which may be solid, liquid or gas, while an aqueous solution is formed with water as solvent.Explanation:
A solution in general is a homogeneous mixture in which a substance, named solute, is dissolved, in other substance, name solvent.
Solutions may be in solid, liquid or gas state. There are many kind of solvents. Usually, in a lab you work with liquid solutions. Some liquid solvents are: ethanol, glycerin, hexane, benzene, and water, among many others.
Aqueous solution is a solution where the solvent is water. Of course, the solute may be any one: NaCl, sugar, ethanol, an acid, a base, a salt.
What distinguish a solution in general and an aqueous solution is the solvent.
when 2.85 moles of chlorine reacts with excess tin, how many moles of tin choloride are formed?
chlorine by twenty øne piløts
Identify whether each process is either oxidation or reduction:
Al → Al3+ + 3 e-
S2- → S + 2 e-
Cu → Cu2+ + 2 e-
Show ALL work.
Answer:
Al → Al³⁺ + 3 e⁻, is an oxidation process.
S²⁻ → S + 2 e⁻, is an oxidation process.
Cu → Cu²⁺ + 2 e⁻, is an oxidation process.
Explanation:
The oxidation-reduction reaction contains a reductant and an oxidant (oxidizing agent).The oxidation process is the process in which electrons are lost and produce positively charged ions.The reduction process is the process in which electrons is gained and negatively charge ions are produced.So,
Al → Al³⁺ + 3 e⁻, is an oxidation process.Al loses 3 electrons and produce Al³⁺c
S²⁻ → S + 2 e⁻, is an oxidation process.S²⁻ loses 2 electrons and produce S.
Cu → Cu²⁺ + 2 e⁻, is an oxidation process.Cu loses 2 electrons and produce Cu²⁺.
All the given processes (Al becoming Al₃+, S₂- becoming S, and Cu becoming Cu₂+) are examples of oxidation, as each involves the loss of electrons.
Explanation:To determine whether each process is oxidation or reduction, we will look at the change in electron configuration for each reaction.
Al → Al₃+ + 3 e-: Here, Aluminum (Al) is losing three electrons to form Al₃+. This is an oxidation process because oxidation is characterized by the loss of electrons.S₂- → S + 2 e-: In this process, the sulfide ion (S₂-) is losing two electrons to become elemental sulfur (S). This is also an oxidation process, as it involves the loss of electrons.Cu → Cu₂+ + 2 e-: Copper (Cu) loses two electrons to form Cu₂+. Similar to the previous examples, this is an oxidation process because it involves the electron loss.Thus, all the given processes are examples of oxidation, where each element or ion loses electrons.
In what way does hemoglobin act as a buffer against changes in blood ph?
Answer:
Explanation:
Hemoglobin removes excess protons from the red blood cells so that they can be excreted through the kidneys.
Hemoglobin binds some of the excess protons released by carbonic acid.
Subsequent binding of oxygen is drastically reduced after the first one is bound.
Hemoglobin produces protons or hydroxide ions as needed to alter the blood pH.
Answer:
Excess acids in the red blood cells are removed by the hemoglobin
Explanation:
In what way does hemoglobin act as a buffer against changes in blood ph?
Excess acids in the red blood cells are removed by the hemoglobin . it is a good receptor of excess proton released by carbonic acid.
It helps to remove acids before it affects the PH of the blood. deoxygenated hemoglobin are better receptor of proton than the oxygenated one.
If hemoglobin does not act as a buffer, there will be changes in the blood's PH and can poison the blood.
How many significant figures are in 253.00 g?
There are five significant figures
Hope this helps and have a fabulous day :)
It’s five significant figures
Fernanda looked at a sample of paint under a microscope. At right is the sketch she made of what she saw. Label A points to the solid particles of pigment that give the paint its color. The solid particles are the . Label B represents the liquid surrounding the solid particles. This liquid is called the for this mixture. This paint does not settle over time, so it is an example of a .
Answer:dispersed state
dispersed medium
colloid
Answer:
Label A points to the solid particles of pigment that give the paint its color. The solid particles are the (dispersed state.)
Label B represents the liquid surrounding the solid particles. This liquid is called the (Dispersed Medium)
This paint does not settle over time, so it is an example of a (Colloid)
Explanation:
Fernanda looked at a sample of paint under a microscope. At right is the sketch she made of what she saw.
The tendency of an element to react with other elements to produce compounds is called
Answer:
Organic compound is the correct answer
Explanation:
When light shines on a sample, each element emits specific wavelengths producing a unique fingerprint called its ______ spectra. A) infrared B) line C) raman D) ultraviolet
Answer:
B.
Explanation:
Answer:
B) line is the correct answer.
Explanation:
When light shines on a sample, each element emits specific wavelengths producing a unique fingerprint called its line spectra.
The line spectrum is electromagnetic spectra consist of discrete spectra lines.
When the atoms are excited they emit ray of specific wavelengths that correspond to various colors. The emitted ray can be seen as a range of colored line, this range of colored lines is termed as line spectra.
lines spectra are usually utilized to recognize atoms and molecules. Each element has individual line emission spectra.
NEED HELP!!!
Which of the following is true about the concept of half-life?
a. Half-life measures the rate of decay of a radioisotope.
b. The shorter the half-life, the more dangerous the radioisotope.
c. Half-life predicts which atoms in a radioactive sample will decay.
Answer:
b. The shorter the half-life, the more dangerous the radioisotope.
The shorter the half-life, the more dangerous the radioisotope. Therefore, the correct option is option B.
What is half-life?The half-life is the length of time required for a single quantity (of substance) to drop to half its initial value (symbol t12). The phrase is widely used in nuclear physics to describe how quickly unstable atoms dissolve radioactively or how long stable atoms endure.
The term is often used more generally to indicate any type involving exponentially decaying. In the medical sciences, for example, the biological ½ of drugs and other chemicals in the human body is a word. Half-opposite life's in exponential growth is time's doubling. The shorter the half-life, the more dangerous the radioisotope.
Therefore, the correct option is option B
To learn more about half-life, here:
https://brainly.com/question/24710827
#SPJ6
To balance a chemical equation it may be necessary to adjust the
Answer:
To balance a chemical equation it may be necessary to adjust the coefficients.Explanation:
The coefficients of a chemical equation are the numbers that you put in front of each reactant and product. They are used to balance the equation and comply with the law of mass conservation.
By adjusting the coefficients you obtain the relative amounts (moles) of each product and reactant, i.e. the mole ratios.
Here an example.
The first information is what is called a word equation. E.g. nitrogen and hydrogen react to form ammonia:
Word equation: hydrogen + nitrogen → ammoniaSkeleton equation: H₂ + N₂ → NH₃This equation shows the chemical formulae but it is not balanced. The law of mass conservation is not observed.
So, in order to comply with the law of mass conservation you adjust the coefficients as follow.
Balanced chemical equation: 3H₂ + N₂ → 2NH₃As you see, it was necessary to modify the coefficients. Now the law of conservation of mass is observed and you get the mole ratios:
3 mol H₂ : 1 mol N₂ : 2 mol NH₃
Which metal can be used as a sacrificial electrode to prevent the rusting of an iron pipe?
manganese The metal that is used as a sacrificial electrode to prevent the rusting of iron is manganese.
What is the concentration of hydrogen ions commonly expressed as
Answer: pH scale
Explanation:
Which of these is the percent of error in evaluating the molecular mass of a compound if the experimental value was 105.2 amu and the known value was 107.5 amu? f 2.1% g 4.2% h 3.3% j 1.0%
Answer:
The percent error, % error, is 2.1% (option f)Explanation:
1) Data:
a) Experimental value, m₁ = 105.2 amu
b) Known value, m = 107.5 amu
b) % error = ?
2) Formulae:
a) absolute error = | experimental value - known value|
b) % error = [ absolute value / known value ] × 100
3) Solution:
a) absolute error = | m₁ - m | = | 105.2 amu - 107.5 amu | = 2.3 amu
b) % error = [ 2.3 amu / 107.5 amu ] × 100 = 2.1% ← answer
R-12 should be recycled instead of vented to the atmosphere because
A. recycling companies offer large financial incentives.
B. it has been proven to deplete the Earth's ozone layer.
C. R-12 is expensive.
D. R-12 is unstable.
I believe is B if not then it's A
Answer:
Option (B)
Explanation:
R-12 is known as the Dichloro-difluoro-methane and it is a colorless gas. It is was earlier used in the refrigerators, vehicles air conditioning, and aerosol spray. The use of this R-12 was found to be depleting the ozone layer which was not a positive effect on the earth. Due to this, the use of this gas was banned and alternative energy resources were used. Its products containing this R-12 gas were not expensive and they were stable enough.
Hence, the correct answer is option (B).
What is the equilibrium constant expression for the following reaction?
COCl2(g) = CO(g) + Cl2(g)
Keq=(COCl2)/(CO)+(Cl2)
Keq= (CO)(Cl2)/(COCl2)
Keq=(COCl2)/(CO)(Cl2)
Keq=(CO)+(Cl2)/(COCl2)
Answer:
Keq = [CO][Cl₂]/[COCl₂].
Explanation:
For the balanced reaction:
COCl₂(g) ⇄ CO(g) + Cl₂(g).
The equilibrium constant can be expressed as concentration equilibrium constant (Kc) or pressure equilibrium constant (Kp).
The equilibrium constant is the ratio of the product of products concentrations to the product of the reactants concentrations.
Keq = [CO][Cl₂]/[COCl].
Which of the following statements regarding glucose is FALSE?a) Glucose is the main component of starch and glycogen.b) Glucose is also called blood sugar.c) Glucose is the most common disaccharide in our diet.d) Glucose is the most important carbohydrate fuel for the human body.
Glucose is the most common disaccharide in our diet is the false statement regarding glucose.
What is the chemical formula of glucose?The chemical formula of glucose is written as C₆H₁₂O₆.
Starch and glycogen is the highly branched compound or the polymers, which can be formed from the fundamental monomer unit of glucose. Glucose is also present in the blood of as a blood sugars and used as a source of energy or we can say that fuel for the human body. Glucose is a monosaccharide, it means it will not able to break down in following sub units.
Hence, option (c) is false because glucose is a monosaccharide.
To learn more about glucose, visit the below link:
https://brainly.com/question/461228
The false statement about glucose is (C), that is Glucose is the most common disaccharide in our diet. Glucose is actually a monosaccharide. Common disaccharides include sucrose, lactose, and maltose.
To determine which statement regarding glucose is FALSE, let's analyze the given options:
a) Glucose is the main component of starch and glycogen. This is true, as both starch and glycogen are polysaccharides composed of glucose units.b) Glucose is also called blood sugar. This is true, because glucose circulates in the blood as a primary energy source.c) Glucose is the most common disaccharide in our diet. This statement is false. Glucose is a monosaccharide, not a disaccharide. Common disaccharides include sucrose, lactose, and maltose.d) Glucose is the most important carbohydrate fuel for the human body. This is true, as it is the primary energy source for cellular functions.The ph of a solution prepared by mixing 45.0 ml of 0.183 m koh and 35.0 ml of 0.145 m hcl is ________.
Answer:
12.6.
Explanation:
We should calculate the no. of millimoles of KOH and HCl:no. of millimoles of KOH = (MV)KOH = (0.183 M)(45.0 mL) = 8.235 mmol.
no. of millimoles of HCl = (MV)HCl = (0.145 M)(35.0 mL) = 5.075 mmol.
It is clear that the no. of millimoles of KOH is higher than that of HCl:So,
[OH⁻] = [(no. of millimoles of KOH) - (no. of millimoles of HCl)] / (V total) = (8.235 mmol - 5.075 mmol) / (80.0 mL) = 0.395 M.
∵ pOH = -log[OH⁻]
∴ pOH = -log(0.395 M) = 1.4.
∵ pH + pOH = 14.
∴ pH = 14 - pOH = 14 - 1.4 = 12.6.
12.6 is the pH of a solution prepared by mixing 45.0 ml of 0.183 m KOH and 35.0 ml of 0.145 m HCl.
How we calculate pH?
pH of the solution can be calculated as pH = 14 - pOH.
First of all we have to calculate the concentration of OH⁻ ions as follow:
Total volume of the solution = 45ml + 35ml = 80ml
Concentration of OH⁻ in terms of mole is calculated as:
[OH⁻]=(no. of millimoles of KOH - no. of millimoles of HCl)/Total volume
Given that, concentration of KOH = 0.183m
Volume of KOH = 45ml
Concentration of HCl = 0.145m
Volume of HCl = 35ml
Millimoles can be calculated as:
millimoles = concentration × volume
No. of millimoles of KOH = 0.183 M × 45.0 mL = 8.235 mmol
No. of millimoles of HCl = 0.145 M ×35.0 mL = 5.075 mmol
Now, [OH⁻] = 8.235 mmol - 5.075 mmol / 80.0 mL = 0.395 M
pOH = -log[OH⁻]
pOH = -log(0.395)
pOH = 1.4
Therefore, pH = 14 - 1.4 = 12.6
Hence, 12.6 is the pH of the solution.
To know more about pH, visit the below link:
https://brainly.com/question/26767292
You are presented with a mixture of iron beads and iron filings. How can you separate them?
Use a magnet
Dissolve the fillings in water
Use a screen
Distillation
NEED HELP ASAP
Answer:
By using a screen
Answer:
Use a screen
Explanation:
plants take in carbon dioxide from the air through holes in the
a. xylem
b. spongy layer
c. palisade layer
d. vascular bundle
Answer:
c. palisade layer
A stable atom that has a large nucleus most likely contains....?
A.) more neutrons than protons
B.) more protons than neutrons.
C.) equal numbers of protons and neutrons.
D.) changing numbers of protons and neutrons.
A. More neutrons than protons
it would likely include more neutrons than protons.
For compounds, the basic structural unit representing the compound is the atom.
a. true
b. false
The statement provided is false; the basic structural unit of a compound is the molecule, not the atom. Molecules consist of atoms from different elements bonded in fixed ratios, forming the substance known as a compound.
Explanation:The statement 'For compounds, the basic structural unit representing the compound is the atom.' is false. The smallest particle of most compounds is called a molecule. For instance, a water molecule (H₂O) is always made up of one atom of oxygen and two atoms of hydrogen. This molecule is the basic unit that represents the compound water, not a single atom. Compounds are characterized by atoms of different elements bonded together, and these atoms are in fixed, whole-number ratios.
Isomers are molecules that have the same number and type of atoms but arranged differently. For example, molecules with the formulas CH₃CH₂COOH and C₃H₆O₂ could indeed be structural isomers since they have the same molecular formula but could have a different arrangement of the atoms within the molecule.
Atomic Elements
Most elements exist as individual atoms as their basic unit. When combined in specific ways, these atoms form molecules, which are the basic units of compounds. A single atom by itself cannot represent a compound; it is the molecule, composed of two or more atoms, that does so.
The radioactive element carbon-14 has a half-life of 5750 years. a scientist determined that the bones from a mastodon had lost 72.6% of their carbon-14. how old were the bones at the time they were discovered?
Under which set of conditions is δgrxn for the reaction a(g) → b(g) most likely to be negative?
Answer:
delta G = -ve.. This means the rxn is spontaneous
Explanation:
For spontaneous rxn
Delta H = - ve
Delta S = +ve
And no. Of moles at product side should be less than tha reactant side.
I wrote all i know.. Hope this helps you
Answer:
This question is incomplete but the completed question is below
Under which set of conditions is ΔGrxn for the reaction A(g)→B(g) most likely to be negative?
Under which set of conditions is for the reaction most likely to be negative?
(a) PA=0.010 atm; PB=0.010 atm
(b) PA=0.010 atm; PB=10.0 atm
(c) PA=10.0 atm; PB =0.010 atm
(d) PA=10.0 atm; PB =10.0 atm
The correct option is (c)
Explanation:
The Gibb's free energy (ΔG) of the reaction will be negative when the reaction is spontaneous and a reaction is said to be spontaneous when more products are been formed.
When you consider the reaction provided in the question, the "g" in bracket means gas while A represent reactant(s) and B represents product(s)
When a reaction involves gases, an increase in pressure causes more products to be formed hence the pressure on the reactant side (PA) will most likely be more than the pressure on the product side (PB). The only option that has more pressure on the reactant side (PA = 10.0 atm) than on the product side (PB = 0.010 atm) is option c.
Cup A and cup B are identical. They contain equal volumes of soup at equal temperatures. Both cups are put in a refrigerator. Cup A has a lid, but cup B does not. Which statement best explains why cup A will cool more slowly than cup B?
A.
Water vapor won’t be able to escape from cup A.
B.
The most energetic water molecules from cup A will escape more rapidly.
C.
No molecules will be able to evaporate at the surface of cup B.
D.
No molecules will be able to evaporate at the surface of cup A.
Answer:
A
Explanation:
Answer: Option (D) is the correct answer.
Explanation:
It is known that in a closed system there will no exchange of heat or matter from the system to the surrounding. Whereas in an open system there will be exchange of both heat and energy from the system to the surrounding and vice versa.
Therefore, in the given situation cup A is a closed system and cup B is an open system. Hence, there will be no exchange of heat or matter from cup A to system and surrounding. So, it will cool slowly that cup B.
Thus, we can conclude that the statement no molecules will be able to evaporate at the surface of cup A, best explains why cup A will cool more slowly than cup B.
An expandable container of oxygen gas has a volume of 125 mL and a temperature of 25.0?C. What volume will the gas occupy at 55°C?
Answer:
137.6 mL.
Explanation:
We can use the general law of ideal gas: PV = nRT.where, P is the pressure of the gas in atm.
V is the volume of the gas in L.
n is the no. of moles of the gas in mol.
R is the general gas constant,
T is the temperature of the gas in K.
If n and P are constant, and have different values of V and T:(V₁T₂) = (V₂T₁)
Knowing that:
V₁ = 125.0 mL, T₁ = 25°C + 273 = 298 K,
V₂ = ??? mL, T₂ = 55°C + 273 = 328 K,
Applying in the above equation(V₁T₂) = (V₂T₁)
∴ V₂ = (V₁T₂)/(T₁) = (125.0 mL)(328 K)/(298 K) = 137.6 mL.
Final answer:
To find the volume of the gas at a different temperature, we can use Charles's Law. By using the formula V1/T1 = V2/T2 and substituting the known values, we can determine that the volume of the gas at 55°C is 275 mL.
Explanation:
To solve this problem, we can use Charles's Law, which states that the volume of a gas is directly proportional to its temperature, assuming the pressure remains constant. We can use the formula:
V1/T1 = V2/T2
Given that the initial volume (V1) is 125 mL and the initial temperature (T1) is 25.0°C, we can substitute these values into the formula. Rearranging the formula to solve for V2, we get:
V2 = (V1*T2)/T1
Substituting the known values, we have:
V2 = (125 mL * 55 °C) / 25.0 °C = 275 mL
Therefore, the volume of the gas at 55°C is 275 mL.
A change in the amount of heat energy lost or gained by a system during a process is_________________________
Answer:
chemical change
According to the storage ladder protocol, raw meat should be stored on shelves based on its? A.Minimum internal cooking temperature. B.Expiration date C. Meat should never be stored on shelves D.Maximum internal cooking temperature
Answer:
D.Maximum internal cooking temperature
Explanation:
According to the Storage Ladder Protocol, food storage in refrigerator should have a proper rules to store them. On the top most shelf, Prepared foods should be kept. On the second shelf, Fruits and Vegetable are kept. Fish and Sea foods are kept on the third shelf. The fourth shelf is reserved for the Beef and Porks. The next shelf is for Ground Meat. The last shelf is for Poultry items. So, this proves that the Ground Beef should be stored above the Chicken. A diagram is attached below to explain the storage order in a more appropriate manner.
According to the Storage Ladder Protocol, raw meat should be stored on shelves based on its Minimum internal cooking temperature
The storage ladder protocol is a sets of rules created to make sure that varieties of unprepared and prepared food are properly stored in a refrigerator.
Further ExplanationThe storage ladder protocol is meant to determine which shelf each variety of food should be stored on and also provides a guide as to which food should be below or above.
For example, prepared food must be stored on the top shelf, Foods and vegetables are stored on the second shelf, fish and seafood should be stored on the third shelf, beef and pork should be kept on the fourth shelf, Ground meat should be stored on the fifth shelve while poultry items should be kept on the bottom shelf.
Also, to ensure proper food hygiene, make sure that the temperature of your fridge is set between 0 and 5 degrees Celsius. If the temperature is maintained within that range, it will slow down the rate at which the food gets to spoil and also prevent harmful bacteria from multiplying.
Also, do not consume any food that has passed its expiry date because it will be easy for bacteria to grow on such food.
LEARN MORE:
How should food be stored to avoid cross-contamination: https://brainly.com/question/4415007According to the storage ladder protocol, raw meat should be stored on shelves based on its? https://brainly.com/question/12570432KEYWORDS:
refrigeratorstorage ladder protocolraw meattemperaturerules