Answer:
element
Explanation:
it is use full for you thanks
Scientific explanations
can include supernatural explanations
cannot include supernatural explanations
must include supernatural explanations
O must show supernatural forces do not exist
I think that it's cannot include supernatural explanations, or C.
If i got it wrong sorry
A certain sample of rubidium has just two isotopes, 85Rb (mass = 84.911amu) and 87Rb (mass = 86.909amu). The atomic mass of this sample is 86.231 amu. What are the percentages of the isotopes in this sample?
Answer:
[tex]\%_{Rb-85}=33.9\%[/tex]
[tex]\%_{Rb-87}=66.1\%[/tex]
Explanation:
Hello,
In this case, for the natural occurring isotopes we equal the average atomic mass via:
[tex]86.231=84.911*\%_{Rb-85}+86.909*\%_{Rb-87}[/tex]
Thus, since both percentages of abundance must turn out 100%, we can write:
[tex]\%_{Rb-85}+\%_{Rb-87}=100\%\\\\\%_{Rb-85}=100\%-\%_{Rb-87}[/tex]
So we can write:
[tex]86.231=84.911*(100\%-\%_{Rb-87})+86.909*\%_{Rb-87}[/tex]
Solving for the percentage of abundance of Rb-87:
[tex]86.231=84911.00\%-84.911\%_{Rb-87}+86.909*\%_{Rb-87}\\\\\%_{Rb-87}=\frac{86.231-84.911}{-84.911+86.909}\\ \\\%_{Rb-87}=66.1\%[/tex]
Therefore, the percentage of abundance of Rb-85 turns out:
[tex]\%_{Rb-85}=100\%-66.1\%\\\\\%_{Rb-85}=33.9\%[/tex]
Best regards.
Considering the definition of atomic mass, isotopes and atomic mass of an element, the percentages of the isotopes in this sample are:
percent of Rb-87= 66.07%percent of Rb-85 = 33.93%
First of all, the atomic mass (A) is obtained by adding the number of protons and neutrons in a given nucleus of a chemical element.
The same chemical element can be made up of different atoms, that is, their atomic numbers are the same, but the number of neutrons is different. These atoms are called isotopes of the element.
On the other hand, the atomic mass of an element is the weighted average mass of its natural isotopes. In other words, the atomic masses of chemical elements are usually calculated as the weighted average of the masses of the different isotopes of each element, taking into account the relative abundance of each of them.
In this case, a certain sample of rubidium has just two isotopes, 85Rb (mass = 84.911amu) and 87Rb (mass = 86.909amu). Then, the average mass of lithium can be calculated as:
84.911× percent of Rb-85 + 86.909× percent of Rb-87= 86.231
Since both abundance percentages must be 100%, you can write:
percent of Rb-85 + percent of Rb-87= 100
Then:
percent of Rb-85 = 100% - percent of Rb-87
So, replacing this expression in the first equation:
84.911× (100% - percent of Rb-87) + 86.909× percent of Rb-87= 86.231
Solving:
84.911×100% - 84.911× percent of Rb-87 + 86.909× percent of Rb-87= 86.231
8491.1% -84.911× percent of Rb-87 + 86.909× percent of Rb-87= 86.231
-84.911× percent of Rb-87 + 86.909× percent of Rb-87= 86.231 - 8491.1%
-84.911× percent of Rb-87 + 86.909× percent of Rb-87= 86.231 - 84.911
1.998× percent of Rb-87= 86.231 - 84.911
1.998× percent of Rb-87= 1.32
percent of Rb-87= 1.32÷ 1.998
percent of Rb-87= 0.6607
percent of Rb-87= 66.07%
Therefore, the percentage of abundance of Rb-85 is:
percent of Rb-85 = 100% - percent of Rb-87
percent of Rb-85 = 100% - 66.07%
percent of Rb-85 = 33.93%
Finally, the percentages of the isotopes in this sample are:
percent of Rb-87= 66.07%percent of Rb-85 = 33.93%Learn more:
brainly.com/question/14403750?referrer=searchResults brainly.com/question/10043246?referrer=searchResults brainly.com/question/15553207?referrer=searchResultsAn unidentified solid substance has a mass of 769.09 grams and a volume of 17.38 cm/3 What is the density of this substance?
Answer:
The answer is
44.25 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question
mass of substance = 769.09 g
volume = 17.38 cm³
The density is
[tex]density = \frac{769.09}{17.38} \\ \equiv44.2514384...[/tex]
We have the final answer as
44.25 g/cm³Hope this helps you
g Five calcite, CaCO3 (MW 100.085 g/mol), samples of equal mass have a total mass of 12.3±0.1 g. What is the absolute uncertainty (grams) of calcium in each average calcium mass of the sample? Assume that the relative uncertainties in atomic mass are small compared the uncertainty of the total mass.
Answer:
The value is [tex]L = 0.985 \pm 0.00801 \ g[/tex]
Explanation:
From the question we are told that
The molar mass of [tex]CaCO_3[/tex] is [tex]MW = 100.085 \ g/mol[/tex]
The total mass is [tex]m_g = 12.3 \ g[/tex]
The uncertainty of the total mass is [tex]\Delta g = 0.1[/tex]
Generally the molar weight of calcium is [tex]M_c = 40 g/mol[/tex]
The percentage of calcium in calcite is mathematically represented as
[tex]C = \frac{40.07}{100.085} * 100[/tex]
[tex]C = 40.03 \% [/tex]
Generally the mass of each sample is mathematically represented as
[tex]m= \frac{m_g}{5}[/tex]
[tex]m= \frac{12.3}{5}[/tex]
[tex]m= 2.46 \ g [/tex]
Generally mass of calcium present in a single sample is mathematically represented as
[tex]m_c = 2.46 * \frac{40.04}{100}[/tex]
[tex]m_c = 0.985 \ g [/tex]
The uncertainty of mass of a single sample is mathematically represented as
[tex]k = \frac{\Delta g }{5}[/tex]
[tex]k = \frac{0.1 }{5}[/tex]
[tex]k = 0.02\ g [/tex]
The uncertainty of mass of calcium in a single sample is mathematically represent
[tex]G = \frac{0.02 * 40.04}{ 100}[/tex]
[tex]G = 0.00801 \ g [/tex]
Generally the average mass of calcium in each sample is
[tex]L = 0.985 \pm 0.00801[/tex]
What element is CU?plz helpppp
The United Nations hires a global firm to study digital communications around the world. Here is what that firm wrote based on its research. Many people in the world have little experience with computers, and only one-fifth of the world’s population has Internet access. The differences in the ability to use this technology make it challenging to reach people from around the world. The firm’s findings are best described as the digital divide. inequality divide. Internet divide. computer divide.
Answer:
The answer is digital divide.
Explanation:
Digital divide is the answer because if there is only one-fifth of the world that has computers then the United Nations cannot communicate with everyone ,so there is a digital divide and that is your answer. Also, I took the test and I got the question right.
Answer:
The answer is digital divide.
Explanation:
Digital divide is the answer because if there is only one-fifth of the world that has computers then the United Nations cannot communicate with everyone ,so there is a digital divide and that is your answer. Also, I took the test and I got the question right.
It took 73.2 J of heat to raise the temperature of 10.0g of a substance 8.58°C. What is the
specific heat of the substance?
Answer:
[tex] \boxed{\sf Specific \ heat \ of \ the \ substance \ (c) = 0.85 \: J/g \degree C } [/tex]
Given:
Mass (m) = 10.0 g
Rise in temperature (∆T) = 8.58°C
Energy required (Q) = 73.2 J
To Find:
Specific heat of the substance (c)
Explanation:
Specific heat (c) of a substance is the energy required to raise the temperature of one gram of the substance by one degree Celsius.
Formula of specific heat is given as:
[tex] \boxed{ \bold{c = \frac{Q}{m\Delta T}}}[/tex]
By substituting value of Q, m & ∆T in the formula we get:
[tex] \sf \implies c = \frac{73.2}{10 \times 8.58} \\ \\ \sf \implies c = \frac{73.2}{85.8} \\ \\ \sf \implies c = 0.85 \: J/g \degree C [/tex]
What do sponges eat?
Answer:
crabby patties I'm not good at english probably spelled that wrong
Six atoms of the peptide bond group are always planar due to the ____________. Dipole of amide linkage of a peptide bond is due to partially ___________charged carbonyl oxygen and partially ___________ charged amide nitrogen. Select one: a. phi and psi angles; negatively; positively b. trans position between amide hydrogen and carbonyl oxygen; positively; negatively c. resonance structure; negatively; positively d. resonance structure; positively; negatively e. trans position between amide hydrogen and carbonyl oxygen; negatively; positively
Answer:
D
Explanation:
Resonance because the lone pairs undergo resonance due tothe partial bond relationship BTW Carbon - Nitrogen bond so the bond length shortens making the six atoms of peptide bond planar
And positive because The dipole of amide linkage of a peptide bond is as a result of the partially positively charged carbonyl oxygen and partially positively charged amide oxygen.
And the negative because The carboxylic acid group -COOH is an acid donates H+ and -NH2 being a base is H+ so causes a partial negative charge to develop on -COO(-) and partial positive charge to develop on -NH3(+).l
Which of these is a chemical property of a material?
density
flammability
color
brittleness
Answer:
Flammability.
Explanation:
Chemical properties of a substance are properties of a substance that occur in the chemical reactions in which it is involved. These are the basis for the classification of substances, such as metals, halogens, acids, alcohols, alkenes, arenes, etc. A class of substances is characterized by chemical properties common to that group. Differences in the chemical and physical properties of substances allow the substance to be identified, and the components of a mixture of substances to be separated and purified.
The chemical properties of a substance are its chemical stability, reactivity, oxidizability, acidity, bromine number, polymerisability, flammability, toxicity, etc. These can be determined by chemical exposure.
Where are the most reactive elements on the periodic table? What makes one element more reactive than another?
These elements are located in the upper right and lower left corners of the periodic table and in certain element groups. The halogens, alkali metals, and alkaline earth metals are highly reactive. The most reactive element is fluorine, the first element in the halogen group.
What is the best definition of physics?
A. The study of different kinds of matter and how they react with
each other
B. The study of how energy and matter interact in the physical world
C. The study of the laws of nature
D. The study of how matter is used in living things
SUNMIT
The solubility of oxygen in water
A) isn't significantly dependent on temperature.
B) is greater in cool liquid water than in warm liquid water.
O C) is responsible for thermoclines.
D) allows for a greater concentration of O2 in water than in air.
Answer:
B) is greater in cool liquid water than in warm liquid water.
Explanation:
The solubility of oxygen in water is more in cold water in comparison to warm water.
The solubility of oxygen in water depends on the temperature as in warm water, more oxygen is released while in cold water, less oxygen is released and more oxygen get dissolved.
Hence, the correct option is "B".
Answer: is greater in cool liquid water than in warm liquid water.
Explanation:
he solubility increases with the increase in the partial pressure of oxygen at a constant temperature and concentration.
how far can you travel in 7 hours if you are driving at a rate of 55 mph
the answer is 385 miles
The radius of a uranium atom is 149 pm. How many uranium atoms would have to be laid side by side to span a distance of 1.66 mm?
Given :
Radius of uranium atom , [tex]R=149\ pm = 149\times 10^{-12}\ m[/tex] .
To Find :
How many uranium atoms would have to be laid side by side to span a distance of 1.66 mm .
Solution :
Diameter of uranium atom :
[tex]D=2r=2\times 149\times 10^{-12}\ m\\\\D=298\times 10^{-12}\ m[/tex]
Number of atoms are :
[tex]n=\dfrac{D}{d}\\\\n=\dfrac{1.66\times 10^{-3}\ m}{ 298\times 10^{-12}\ m}\\\\n=5.57\times 10^{6}[/tex]
Hence , this is the required solution .
1. Convert each of the following into scientific notation.
Answer:
[tex]7.27[/tex] x [tex]10^{2}[/tex]
[tex]1.72[/tex] x [tex]10^{5}[/tex]
[tex]9.84[/tex] x [tex]10^{-4}[/tex]
[tex]2[/tex] x [tex]10^{4}[/tex]
[tex]1.4[/tex] x [tex]10^{0}[/tex]
[tex]2.560[/tex] x [tex]10^{33}[/tex]
Identify the control group the experimental group the independent variable and the dependent variable
A company wants to test a new dog food that’s aid supposed to help overweight dogs lose weight. 50 dogs are chosen to get the new food and 50 more continue their normal diets after one month the dogs are checked to see if they lose any weight
How many moles of hydrogen atoms are present in a 25.2 g sample of propane, C3H8?
Answer:
Explanation:
mass of the hydrogen atom in C3H8= 4.58 gram
C3H8 8H
25.2 gram x
(3x12)+ 8 8x1
x = 4.58 grams of H
# moles of hydrogen = mass/m.wt
= 4.58/8= 0.57 mole of hydrogen atom
Question 1 2 pts This question is worth 2 points. Using the ruler included below, how long are these crucible tongs?
What assumptions do we make in order to use the Henderson-Hasselbalch equation? a. Both the weak acid and its conjugate base are present initially. b. x (or the change in the reaction) is approximately zero, that is we use the weak acid approximation. c. The final and initial concentration of the acid and it's conjugate base are approximately equal, that is we use the weak acid approximation. d. We only have the weak acid initially.
Answer:
The final and initial concentration of the acid and it's conjugate base are approximately equal, that is we use the weak acid approximation.
Explanation:
The Henderson-Hasselbalch is used to calculate the pH of a buffer solution. It depends on the weak acid approximation.
Since the weak acid ionizes only to a small extent, then we can say that [HA] ≈ [HA]i
Where [HA] = final concentration of the acid and [HA]i = initial concentration of the acid.
It also follows that [A^-] ≈ [A^-]i where [A^-] and[A^-]i refer to final and initial concentrations of the conjugate base hence the answer above.
Transpiration is the loss of water from the leaves of plants. The stomata of leaves must open to allow
carbon dioxide to enter the leaf for photosynthesis, but when they are open, water vapor escapes into
the atmosphere.
HYPOTHESIS: As the intensity of light is increased, the rate of transpiration will increase, as
measured in by the loss of mass of the plant.
Independent variable:
Dependent variable:
Answer:
Independent variable: The light intensity (what YOU CHANGE)
Dependent variable: The rate of transpiration (what YOU MEASURE)
Independent variable are the light intensity that what we change and dependent variable are the rate of transpiration that what we measure.
What is photosynthesis ?Photosynthesis is the process that can be used by the plants and other animals to covert light energy into the chemical energy. Photosynthesis is the main source of food in the earth.
Photosynthesis is the process in which oxygen is released. For survival oxygen is very important, from this process we obtain sufficient amount of oxygen.
The dependent variable is the rate of transpiration and the independent variable is time.The dependent variable is the rate of transportation because it is depends on the environmental factor the plant is placed.
Thus,Independent variable are the light intensity that what we change and dependent variable are the rate of transpiration that what we measure.
To learn more about the photosynthesis, follow the link;
https://brainly.com/question/1388366
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Electrons are embedded in a mass of positively
charged matter.
Answer:
plum pudding model .
Explanation:
the electrons were 'like plums embedded in a pudding'. Also called the Raisin Bread Model.
Which of the following describes a particle that contains
36 electrons, 49 neutrons, and 38 protons?
an ion with a charge of 2-
an ion with a charge of 2+
an atom with a mass of 38 amu
an atom with a mass of 49 amu
Od
Answer:
an ion with charge of 2+
Explanation:
proton and electron numbers do not cancel out...
it has 2 more protons than electrons.
since protons carry a positive charge, a charge of 2+ is now carried by the ion.
it is no longer called an atom as the charges do not cancel out.
Answer: An ion with a charge of +2.
Explanation:
How many moles are there in 2.59x1024 molecules CO2?
Answer:
2.59
x
1024
=
C
O
2
=
Explanation:
The mass of the whole watermelon is 300g.
What is the mass of all 6 watermelon slices?
The nucleus has almost _____ the mass of the atom. It is made up of protons (+) and neutrons (0)
Answer:
1/100,000
Explanation:
its radius is only about 1/100,000 of the total radius of the atom. if an atom were the size of a football stadium, the nucleus would be about the size of a pea! Electrons have virtually no mass, but protons and neutrons have a lot of mass for their size. As a result, the nucleus has virtually all the mass of an atom.
in an investigation that uses the scientific method which step immediately follows asking a question
Answer:
Infer and form a hypothesis
Changes in the temperature of an ice cube taken every minute for 15 minutes line graph scatter plot bar graph histogram
Answer:
1st part: line graph
2nd part: bar graph
Explanation:
edge, yw!
When solid converts to liquid then heat is required to break the intermolecular forces of attraction between the particles. Therefore, 1st part is line graph and 2nd part is bar graph.
What is phase transition?Phase transition is a process in which transition takes place from one state to another of a medium on changing temperature or pressure. Phase transition is a physical process as there is no breaking of old bond and forming of new bonds takes place.
During phase transition temperature remain constant as the extra heat that is given to the system that goes into breaking of intermolecular forces of attraction between the particles. So overall temperature remains same but heat keeps on increasing. 1st part is line graph and 2nd part is bar graph.
Therefore, 1st part is line graph and 2nd part is bar graph.
To learn more about phase transition, here:
https://brainly.com/question/3255181
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Separate the list P, F, V, v, rho, T, a, m, L , and t into intensive properties, extensive properties and non-properties.
Answer:
Generally intensive properties are properties that are dependent on mass
So from the list given in the question we see that
P => pressure
V => volume
[tex]\rho[/tex] => density
T => tension
Are intensive properties
Generally extensive properties are properties that are increase or decreased by mass i.e that scale with mass i.e the are properties that their value is proportional to the quantity of matter(mass) in the system
So from the list given in the question we see that
m => mass
V => volume
Non -properties are
F => Force
a = > acceleration
L => length
t => time
v => velocity
Explanation:
As per the question separate the P, V, F, v and rho and T a and m and L then we have intensive properties and an extensive property and a non extensive property
Generally intensive properties are properties that are dependent on mass So from the list given in the question we see that P => pressure V => volume D => density T => tension Are intensive properties.Learn more about the list P, F, V, v, rho, T, a, m, L.
brainly.com/question/19968870.
Which particles affect the stability in of the atom
The stability of an atom is affected by the balance between the electrons, protons, and neutrons in an atom.
What are sub-atomic particles?A particle less than an atom is referred to as a subatomic particle. A subatomic particle can either be an elementary particle, which is not made of other particles, or a composite particle, which is composed of other particles, according to the Standard Model of particle physics.
Particles smaller than an atom are referred to as subatomic particles. The three primary subatomic particles present in an atom are protons, neutrons, and electrons.
Learn more about sub-atomic particles at: https://brainly.com/question/16847839
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