Answer:
its 1.04
Explanation:
A sample of boron consist of 10B (mass 10.0 amu) and 11B(mass 11.0). If the average atomic mass of B is 10.8 amu, what is the % abundance of each boron isotope
Answer:
%abundance of isotope B-11 is 80%, therefore, the %abundance of isotope B-10 is 20%.
Explanation:
The average atomic mass of an element is actually a weighted average atomic mass, taking into account the percent abundance of the naturally occurring isotopes of the element.
To calculate the weighted average mass, you must take the sum of atomic masses of all the naturally occurring isotopes multiplied by their %abundance.
Ave At. Mass = sum of [(isotopic mass)(%abundance)]/100
If we let the %abundance of B-11 be represented by X, then the %abundance of B-10 must be (100-X).
Now we can set up the following equation and solve for X
10.8 = [(10)(100-X) + (11)(X)]/100
1080 = 1000 - 10X + 11X
80 = X
So, the %abundance of isotope B-11 is 80%, therefore, the %abundance of isotope B-10 is 20%.
3. Nitrogen contains two naturally occurring isotopes, N-14 with a mass of 14.003 amu and N-15 with a mass of 15.000 amu. What are the percentages of the two isotopes in naturally occurring nitrogen?
Answer:
Explanation:
fe-45 and O-15 im sure :)
what do columns on the periodic table tell us?
Answer:
Column on the periodic table tell the number of valence electrons and the types of chemicals, such as metals, nonmetals, alkaline earth metals, metalloids, halogens, noble gases.
Explanation:
The periodic table is an arrangement of the elements in order of their atomic numbers so that elements with similar properties appear in the same vertical column or group.
if Tim and maliyah went to the moon and the moon is smaller than earth both maliyah and Tim's mass would stay the same and their weight would change
Answer:
no
Explanation:
Weight is a measure of how much gravity pulls on a mass or object. On the moon, there is less gravity pulling on objects, so they weigh less. ... But does its mass changejust because it is on the moon? No, it is still the same size and looks the same, it just has less gravity pulling on it, so it weighs less.
If the temperature is below zero, what will the precipitation most likely be?
A(hail, B(rain, C(snow, D(sleet.
Answer: C Snow
Explanation:
Because the temperature is low and it is below freezing temperature. Sorry if I am wrong.
what is the maximum gauge pressure of waters that can measured using piezometer tube 2m high?
Answer:
P = ρgh = 1000 × 9.81×2 =19.62 kN/m^2
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2. I take and absorb the nutrients that your body needs from your
food and I put it in your bloodstream so your body can use it.
What am l?
Answer:
The small intestine
Explanation:
You are the small intestine
5. Chemistry helps firefighters
A. determine which chemicals to use to fight different types of fires
B. identify the temperatures at which different substances burn
C. know the angles at which they can safely deploy ladders
D. calculate how much water pressure is available at a hydrant
Answer:
A
Explanation:
determine which chemicals to use to fight different types of fires
the only one that relates to chem
Will Co(OH)2 precipitate from solution if the pH of a 0.020 M solution of Co(NO3)2 is adjusted to 8.5? ( Ksp of Co(OH)2 is 1.3×10−15 .)
TRUE CO(OH)₂ will precipitate from the solution if the pH of a 0.020 M solution of CO(NO₃)₂ is adjusted. ; ( TRUE )
Given that:
Ksp of CO(OH)₂ = 1.3 * 10⁻¹⁵
Chemical reaction
CO⁺² + 2OH ----> CO(OH)₂
First step : determine the pOH value
pOH of solution = 14 - pH
= 14 - 8.5 = 5.5
Also
pOH = - log [ OH⁻ ] = 5.5
Therefore : [OH⁻] = - Antilog ( 5.5 )
= 3.16 * 10⁻⁶
[CO⁺²] = 0.02 given that it is obtained from 0.02 M solution of cobalt nitrate
Next step : determine the Ionic product of cobalt hydroxide
Ionic Product ( IP ) = [CO⁺²] [OH⁻]²
= 0.02 * ( 3.16 * 10⁻⁶)²
= 1.99 * 10⁻¹¹
Given that the Ionic product is greater than the Ksp of CO(OH)₂ therefore CO(OH)₂ will precipitate
Hence we can conclude that TRUE CO(OH)₂ will precipitate from the solution if the pH of a 0.020 M solution of CO(NO₃)₂ is adjusted. ; ( TRUE )
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500mg of iron(ll) complex ferrous bisglycinate hydrochloride was dissolved in dilute H2SO4 and titrated with 0.0200 mol. dm3 KMnO4 18.10cm3 of KMnO4 solution were require to reach the end point the equation for the titration reaction is as follows 5Fe2+ + MnO4- + 8H+ - - > 5Fe2+ + Mn2+ +4H2O
Calculate the
1.number of moles of Fe2+ in the capsule
2.mass of iron in the capsul
3.molar mass of the iron (ll) complex assuming 1mole of the complex contains 1mole of iron. (Fe=55.9gmol-1)
Using the stoichiometry of the reaction, we can obtain the molar mass of the complex as 276 g/mol. The number of moles iron II as 0.00181 moles and the mass of iron II as 0.1 g.
Redox reactionA redox reaction is one in which there is loss or gain of electrons. The equation of the reaction is 5Fe2+ + MnO4- + 8H+ - - > 5Fe2+ + Mn2+ +4H2O
Number of moles of permanganate = 0.0200 mol. dm3 * 18.10cm3/1000 L
= 0.000362 moles
If 5 moles of iron II reacted with 1 mole of permanganate
x moles of iron II reacts with 0.000362 moles of permanganate
x = 5 moles * 0.000362 moles/ 1 mole
= 0.00181 moles of iron II
Recall that;
Number of moles = mass/molar mass
Molar mass of iron II = 56 g/mol
0.00181 moles = x/56 g/mol
x = 0.00181 moles * 56 g/mol = 0.1 g
If 1 mole of the complex contains 1 mole of iron then;
0.00181 moles = 500 * 10^-3/MM
MM= 500 * 10^-3/0.00181 moles
MM = 276 g/mol
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What is the pH of the solution obtained by mixing 68.00 mL of 0.280 M HCl and 60.00 mL of 0.125 M NaOH
The pH of the solution is approximately : 1.05
Given data :
volume of HCl = 68.00 mL = 0.068 L
concentration of HCl = 0.280 M
Volume of NaOH = 60 mL = 0.6 L
concentration of NaOH = 0.125 M
Determine the pH of the solutionFirst step : determine the number of mol of HCl and NaOH
mol of HCl = 0.068 * 0.280 = 0.0190 mol HCl
mol of NaOH = 0.06 * 0.125 = 0.0075 mol NaOH volume of
excess moles of H⁺ after reaction = 0.0190 - 0.0075 = 0.0115 mol
Next step : determine the pH value of the solution
Total volume of solution = 0.068 + 0.060 = 0.128
concentration of the solution [ H⁺ ] = excess moles / total volume
= 0.0115 / 0.128 = 0.0898
Therefore
pH = - log [ H⁺ ]
= - log ( 0.0898 ) = 1.047 ≈ 1.05
Hence we can conclude that The pH of the solution is approximately : 1.05 .
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the enzyme urea catalyses this reaction. If urea is added to a solution that contains ammonia and other nitrogen- containing compounds (but no urea), will the urea catalyse any reactions? Explain your answer?
Answer:
The enzyme urease catalyzes the hydrolysis of urea into ammonia and carbon dioxide. If urease is added to any compound which has no urea, it will not catalyze any reaction because if there is no urea, urease will not bind to any substance.
Which process is a chemical change?
burning a match
boiling water
melting ice
breaking glass
Answer:
Burning a match... i'm pretty sure.
Explanation:
All the other are phisical changes while Fire is a chemical reaction.
Answer:
Burning a match is a chemical change.
Explanation:
Burning is defined as the rapid oxidation of a combustible material.
Complete oxidation of the match stick results in an entirely different compound (the ash) while electrons are lost by the wood of the match.
Write a balanced equation for each of the following decomposition reactions:
Solid stannous chlorate decomposes with heat to give stannous chloride and oxygen gas.
Sn(ClO3)2 -> SnCl2 + 3O2
Explanation: There should be equal amounts of each element on both sides. This assumes it’s referring to Sn 2+, and not Sn 4+.
The balanced chemical equation will be:
[tex]\rm \bold{(SnClO_3)_2\;\overset{\Delta}{\rightarrow}\;SnCl_2\;+\;3\;O_2}[/tex]
Stannous chlorate has been also known as Tin chlorate. The compound has been a white crystalline powder and has been used for the sensitization of the metal.
The decomposition of Stannous chlorate under the influence of heat has resulted in the formation of stannous chloride and oxygen gas.
The reaction can be given as:
[tex]\rm (SnClO_3)_2\;\overset{\Delta}{\rightarrow}\;SnCl_2\;+\;O_2[/tex]
The number of atoms on the reactant and the product side is not equal. By putting the coefficient to the compound, the reaction can be balanced. The balanced chemical equation will be:
[tex]\rm \bold{(SnClO_3)_2\;\overset{\Delta}{\rightarrow}\;SnCl_2\;+\;3\;O_2}[/tex]
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If 3.49 g of silver chloride, AgCl, is produced from the reaction of 5.95 g AgNO3 with excess BaCl2,
what is the percentage yield ?
(molar masses: AgCl = 143.4 g/mol, AgNO3 = 169.9 g/mol)
2 AgNO3(aq) + BaCl2(aq) + 2 AgCl(s) + Ba(NO3)2(aq)
Answer:
that not of i grade sorry
Explanation:
Please help! How many orbits will the Bohr models in the fourth period have?
Answer:
32 electron
Thus,the fourth level can hold up to 32 electrons,2 in the s orbital,6 in the three p orbitals,10 in the five d orbitals,and 14 in the seven f orbitals.
What is the purpose of attaching the clip clamp with the graphite of the pencil to the battery
Elements Q and T are widely separated on the electronegativity scale. This indicates that in the compound QT Select one: Q And T are widely separated in atomic number Or the bond is principally ionic in character. Or the heat of formation has a low value. Or the bond is principally covalent in character.
This indicates that in the compound QT the bond is principally ionic in character. It is a fundamental type of chemical bond.
What is an ionic bond?An ionic bond is a type of chemical bond between two atoms due to the attraction between two opposite ions.
These opposite ions in an ionic bonding are referred to as negative ions and positive ions.
An ionic bonding only occurs when the electrons (e-) of a given atom can be transferred to other atoms in the compound.
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Which statement best describes a physical change?
O Changes can occur to certain chemical properties of the substance, but the overall shape of the substance will
remain the same.
Changes can occur to certain physical properties of the substance, but the overall shape of the substance will
remain the same.
O Changes can occur to physical properties of a substance, but the chemical composition of the substance remains
the same.
O Changes can occur to chemical properties of a substance, but the chemical composition of the substance remains
the same.
Answer:
Changes can occur to physical properties of a substance, but the chemical composition of the substance remains
The table below gives the numbers of protons, electrons, and neutrons in four atoms.
Atom
Number of protons
Number of neutrons
Number of electrons
1
9
8
9
2
19
9
18
3
9
9
10
9
10
19
Based on the table, which atom has a charge of -1?
1
2
Оооо
3
4
Answer:
C. Atom 3
Explanation:
I'm sorry if I answered this late, but hope this helps! :D
Answer:
c
Explanation:
edge 2021
How many O atoms are there in 1.51×10^23 molecules of trifluoroacetic acid, C2HF3O2?
Answer:
9.033 × 10²³ molec C₂HF₃O₂ x (2 O atoms / 1 molec C₂HF₃O₂) = 1.8066 x 10²⁴ O atoms
There are 3.01 × 10^23 atoms of oxygen in 1.51×10^23 molecules of trifluoroacetic acid, C2HF3O2.
The formula of trifluoroacetic acid is C2HF3O2
Number of moles of the trifluoroacetic acid(C2HF3O2)is given using the approach;
1 mole of the compound contains 6.02 × 10^23 molecules
x moles of the compound contains 1.51 × 10^23 molecules
x = 1.51 × 10^23 molecules × 1 mole /6.02 × 10^23 molecules
x = 0.25 moles of trifluoroacetic acid.
Now;
Number of O atoms in the sample = 0.25 × 2 × NA
Where; NA = Avogadro's number
Number of O atoms in the sample = 0.25 × 2 × 6.02 × 10^23 atoms
= 3.01 × 10^23 atoms
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What is a type of nuclear reaction in which the nucleus of a heavy atom splits into two or more smaller nuclei that have masses of relatively similar size?
A: gamma radiation
B: nuclear fusion
C: chain reaction
D: nuclear fission
define conductor and insulator ?
Answer:
A conductor is an object or material that conducts heat, electricity, or sound. Examples of metals such as aluminum, steel, iron, and others. Meanwhile, insulators are objects that are difficult to conduct heat, such as ebonite, plastic, cloth, and others
Conductor is something which conducts electricity
examples are copper and other metals
Insulators are quite the opposite, they do not let electricity pass by them, examples are plastics, rubber and wood
What is kinetic energy?
A: energy that depends on an object’s motion
B: energy that exists in the form of heat
C: stored energy that depends on an object’s chemical composition
D: stored energy that depends on an object’s position
Answer:
the answer should be A. energy that depends on an object's motion
Answer: A
Explanation: Kinetic energy is energy of build up of motion .
I’ll give the brainliest answer to whoever helps me with these!! I need them ASAP!
1. How many moles are in 3.63x10^11 atoms of Mt?
2. How many moles are in 5.96g of KNO3?
3. How many moles are in 1.50 grams of CH4?
4. How many liters are in 82.0g KBr?
Answer:
Your question will be shared anonymously with online publishers who may be interested in answering it
Explanation:
make me as brain
Which representative element has the largest atomic radius ?
Answer:
francium
Explanation:
the atomic radius increases from top to bottom in a group, and decreases from left to right across a period.
Which element has four times as many protons in its nucleus than are found in Neon?
A.Si
B.Ca
C.Zr
D. Hg
Answer: Zr or Zirconium
Explanation: Neon has 10 Protons and four times ten is 40. And Zirconium has 40 protons the symbol for Zirconium is Zr
Neon has 10 protons, the element which has four times more protons than Neon in its nucleus is Zirconium(Zr).
What is a proton?Every atom has a proton, a subatomic particle, in its nucleus. The particle possesses an electrical charge that is positive and opposite to the electrons. A single proton has a mass of only [tex]1.673[/tex]×[tex]10^{-27}[/tex] kilogram when isolated. Just slightly less than a neutron's mass.The atomic number is the number of protons in an element's nucleus. Each element is given a unique identification by this number. The number of protons in the nucleus is constant in all atoms of a given element. The nucleus of an atom of pure hydrogen is made up entirely of one proton. All other elements' nuclei almost usually have neutrons in addition to protons.Protons need not just be found in atoms' nuclei. Protons acquire fascinating, peculiar, and potentially hazardous characteristics when they are discovered outside of atomic nuclei, which are analogous to neutrons in comparable situations. Protons have another characteristic, they can be accelerated by electric and/or magnetic fields because they carry an electric charge. During solar flares, a lot of high-speed protons and atomic nuclei holding them are released. The acceleration of the particles by the earth's magnetic field results in geomagnetic storms, which are ionospheric disturbances.To learn more about Proton, refer to https://brainly.com/question/1805828
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Arrange the following ions in order of increasing ionic radius: nitride ion, magnesium ion, fluoride ion, aluminum ion.
Explanation:
Nitride ion > Fluoride ion > Magnesium ion > Aluminum ion
What is the name of the cycle in which decomposes break down animal waste
A. Water cycle
B. Nitrogen cycle
C. Carbon dioxide-oxygen cycle
D. Rick cycle
Answer:
C. Carbon Dioxide-oxygen Cycle
Explanation:
Bacteria plays an important role in carbon cycle. Bacteria are decomposers that break down organic compounds. They decomposes plant and animal waste products and return carbon back in the environment.
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Two cities in Germany are located 25 km apart. What is the
distance in miles?
Answer:
15.5343
Explanation: