Answer:
Seven methods were used to assess water quality in the river system. These methods included single-factor assessment, water quality grading, comprehensive pollution index, the Nemerow pollution index, principle component analysis, fuzzy comprehensive evaluation, and comprehensive water quality identification index.
The electronic transition in a hydrogen atom from n = 7 to n = 2 emits electromagnetic radiation having a longer wavelength than a transition from n = 6 to n = 3.
Answer: I'll leave the answer rounded to three sig figs.
mark me brainlist
So, you can say that in a hydrogen atom, an electron located on
n
i
=
2
that absorbs a photon of energy
4.85
⋅
10
−
19
J
can make the jump to
n
f
=
6
.
Explanation:
The question wants you to determine the energy that the incoming photon must have in order to allow the electron that absorbs it to jump from
n
i
=
2
to
n
f
=
6
.
A good starting point here will be to calculate the energy of the photon emitted when the electron falls from
n
i
=
6
to
n
f
=
2
by using the Rydberg equation.
HELP SOON PLEASE THIS IS DUE TONIGHT! I WILL GIVE BRAINLIEST!
In an experiment where you use wires, a 9 volt battery, and a light bulb; what would be the best conductor to put on the ends of the wires? Please rate the following solution/liquids and their brightness from 1-5
-Tap water
-Baking soda
-Vinegar
-Coca Cola (or any soda, I guess)
Answer:
I would say baking powder maybe or you should try tap water
Answer:
1st one - tap water (ill go over them one by one to help you understand why)
Its honestly rather vinegar or tap water but if I would go with tap water however I could be wrong. I don't take your class lol
Step by step:
First, tap water includes a lot of ions and contaminants. As a result, tap water only contains ions capable of conducting electricity. As a result, tap water is an excellent electrical conductor.
2nd) Ammonia and baking soda are both weak bases. When weak electrolytes dissolve in water, the resulting solution has a low conductivity.
Third, because it releases H+ and CH3COO- ions, the mobility of these ions in the solution assists in electrical conduction. As a result, vinegar is a good electrical conductor.
4th) When dissolved in water, soda compounds (chemicals mostly containing sodium) include ions, and ions assist conduct electricity. As a result, it does not conduct because it lacks ions or charged particles.
Select the statements that correctly describe an comet. Check all that apply
made of metals and gas
made of ice, dust, and gas and display a tail near the Sun
have short orbits that keep them close to the sun
have huge elliptical orbits that take them past Neptune
Answer:
made up of ice dust and gas and display a tail near the sun
Explanation:
6. What is the atomic mass of Hafnium if out of every 200 atoms, 10 have mass 176.00 g/mol, 38 have mass
177.00 g/mol, 54 have mass 178.00 g/mol, 28 have mass 179.00 g/mol, and 70 have mass 180.00 g/mol?
Answer:
ttyhjj
Explanation:
How many atoms are in 1.27 mol of pure aluminum?
Answer:
To determine the amount of atoms (or molecules) present given the moles of an element, you multiply the amount of moles by Avogadro's number,
6.022
⋅
10
23
4 mol
A
l
6.022
⋅
10
23
1
m
o
l
=
2.41
⋅
10
24
atoms/molecules of
A
l
Explanation:
How many milligrams are in 2.89 x 1024 CO2 molecules?
Answer:
2,959.36
Explanation:
There are 2959.36 milligrams present in 2.89 x [tex]10^{24}[/tex] CO2 molecules.
What is molecule?The smallest component of a substance which possesses both its chemical as well as physical characteristics. One or even more atoms make up molecules.
What is milligrams?Such a measure of mass as well as weight that weighs 0.0154 grains or one-thousandth of a gram.
Calculation of milligram in CO2 molecule.
Mass = No. of molecule / molar mass.
Molar mass = 44.02 g/mol.
Mass = 2.89 x [tex]10^{24}[/tex] /[tex]6.023 * 10^{23}[/tex]× 44.02 g/mol.
Mass = 2959.36 milligrams
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22. What is the mass in grams of each of the following?
a. 3.011 x 1023 atoms F
b. 1.50 x 1023 atoms Mg
c. 4.50 x 1012 atoms Cl
d. 8.42 x 1018 atoms Br
e. 25 atoms W
f. 1 atom Au
The mass in grams of 3.011 x 10²³ atoms of F is 9.5 g.
The mass in grams of 1.50 x 10²³ atoms of Mg is 5.98 g.
The mass in grams of 4.50 x 10¹² atoms of Cl is 2.65 x 10⁻¹⁰ g.
The mass in grams of 8.42 x 10¹⁸ atoms of Br is 1.12 x 10⁻³ g.
The mass in grams of 25 atoms of W is 3.1 x 10⁻²¹ g.
The mass in grams of 1 atom of Au is 3.27 x 10⁻²² g.
What is the mass in grams of 3.011 x 10²³ atoms F?
The mass in grams of 3.011 x 10²³ atoms of F is calculated as follows;
6.023 x 10²³ atoms = 19 g of F
3.011 x 10²³ atoms F = ?
= (3.011 x 10²³ x 19 g)/(6.023 x 10²³)
= 9.5 g
The mass in grams of 1.50 x 10²³ atoms of Mg is calculated as follows;
6.023 x 10²³ atoms = 24g of Mg
1.5 x 10²³ atoms F = ?
= (1.5 x 10²³ x 24 g)/(6.023 x 10²³)
= 5.98 g
The mass in grams of 4.50 x 10¹² atoms of Cl is calculated as follows;
6.023 x 10²³ atoms = 35.5 g of Cl
4.5 x 10²³ atoms Cl = ?
= (4.5 x 10¹² x 35.5 g)/(6.023 x 10²³)
= 2.65 x 10⁻¹⁰ g
The mass in grams of 8.42 x 10¹⁸ atoms of Br is calculated as follows;
6.023 x 10²³ atoms = 80 g of Br
8.42 x 10¹⁸ atoms Br = ?
= (8.42 x 10¹⁸ x 80 g)/(6.023 x 10²³)
= 1.12 x 10⁻³ g
The mass in grams of 25 atoms of W is calculated as follows;
6.023 x 10²³ atoms = 74 g of W
25 atoms W = ?
= (25 x 74 g)/(6.023 x 10²³)
= 3.1 x 10⁻²¹ g
The mass in grams of 1 atom of Au is calculated as follows;
6.023 x 10²³ atoms = 197 g of Au
1 atom of Au = ?
= (1 x 197 g)/(6.023 x 10²³)
= 3.27 x 10⁻²² g
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What is the atomic mass of Helium
Answer:
4.002602 u
Explanation
Answer:
4.002602 u
Explanation:
If a aluminum cube had a mass of 20g and the length of each side was 2cm between what to liquids would it float?
Answer:
density=20/8 g/cc=2.5 g/cc
Mercury is more dense, so aluminum will float on it. Water is less dense, so the aluminum will be below water.
Aluminum will float atop mercury because it is more dense than it. Due to water's lower density, the metal will lie below the surface.
What is density?Density is defined as the measure of how densely a material is packed together.
It can also be defined as the mass of a solid substance per unit volume.
Density is important because it enables us to predict which compounds will float and which will sink in a liquid, density is a crucial notion. As long as an object's density is lower than the liquid's density, it will often float.
The term "density" refers to the relationship between a substance's mass and the volume it takes up in space. The mass, size, and arrangement of an object's atoms influence its density.
Density can be expressed as
Density = mass / volume
There are two types of density.
Absolute densityRelative densityThus, aluminum will float atop mercury because it is more dense than it. Due to water's lower density, the metal will lie below the surface.
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What would be the product when combustion reaction occurs in a small tightly-closed container?
Answer:
Incomplete combustion produces carbon monoxide along with some carbon dioxide. Water is always produced during combustion. If the fuel is sulfur containing, carbon disulfide will result as well.
Have a happy day! <3Miss Hawaii
Explanation:
Plss answer!!! I need help fast
Answer:
2 Na atoms
1 C atom
3 O atoms
gram formula weight = 105.99 g
hope this helped :)
Explanation:
→ Na
# of Atoms - 2
→ C
# of Atoms - 1
→ O
# of Atoms - 3
→ gram formula weight (g) : 105.99 g
A volume of 10.0 mL of 25 mg/L Mn2+ solution was diluted to make a solution with the final volume of 50.0 mL. Calculate the concentration (in mg/L) of the final solution
Taking into account the definition of dilution, the concentration of the final solution is 5 mg/L.
First of all, you have to know that dilution is the reduction in concentration of a chemical in a solution. The process consists of adding more solvent to the same amount of solute.
In a dilution the amount of solute does not change, but as more solvent is added, the concentration of the solute decreases.
A dilution is mathematically expressed as:
Ci×Vi = Cf×Vf
where
Ci: initial concentration Vi: initial volume Cf: final concentration Vf: final volumeIn this case, you know:
Ci= 25 mg/L Vi= 10 mL Cf= ? Vf= 50 mLReplacing in the definition of dilution:
25 mg/L × 10 mL= Cf × 50 mL
Solving:
Cf= (25 mg/L × 10 mL)÷ 50 mL
Cf= 5 mg/L
In summary, the concentration of the final solution is 5 mg/L.
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brainly.com/question/20113402?referrer=searchResults brainly.com/question/22762236?referrer=searchResultsTwo carbon atoms (Group 14) bond with two hydrogen atoms (Group 1) to form acetylene (C2H2). How would each carbon atom in acetylene bond?(1 point)
Each carbon atom would share one pair of electrons with the other carbon atom and three pairs with each hydrogen atom.
Each carbon atom would share one pair of electrons with the other carbon atom and two pairs with each hydrogen atom.
Each carbon atom would share one pair of electrons with hydrogen and three pairs with the other carbon atom.
Each carbon atom would share one pair of electrons with hydrogen and one pair with the other carbon atom.
In acetylene each carbon atom share one pair of electrons with hydrogen atom and three pairs with the other carbon atom.
Carbon atom has four electrons its outermost shell it means that it needs four electrons to become stable. In acetylene, two carbon atoms covalently bonded three pairs of electron with each other and the one remaining pair is covalently bonded with two hydrogen atoms.
In this way the carbon as well as hydrogen atoms get stability so we can conclude that in acetylene each carbon atom share one pair of electrons with hydrogen atom and three pairs with the other carbon atom.
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In C2H2, each carbon atom would share one pair of electrons with hydrogen and three pairs with the other carbon atom.
Acetylene has the molecular formula C2H2. We must recall that carbon is a member of group 14 and it is always tetravalent in all its compounds. Hydrogen is always univalent in its compounds except in hydrides.
Since carbon is always tetravalent and hydrogen is univalent,each carbon atom would share one pair of electrons with hydrogen and three pairs with the other carbon atom in C2H2.
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Rock salt is a mixture of salt (sodium chloride) and sand. Describe how you would separate rock salt to obtain salt crystals and pure dry sand. In this question you get marks for how well your answer is written. You will get marks for: spelling, grammar, organising your ideas and information clearly and using key scientific words.
Answer:
pour the rock salt mixture throught a filter made from paper and allow the liquid to filtrate .
Explanation:
Separating Sand and Salt
Probably the easiest method to separate the two substances is to dissolve salt in water, pour the liquid away from the sand, and then evaporate the water to recover the salt.
Pour the liquid through a paper filter made of rock salt mixture and let it filter, after complete filtration we obtain crystals of salt.
What is filtration?Filtration is defined as the technique of removing solid particles from a liquid or gaseous fluid by passing the fluid through a filter media while keeping the solid particles behind.
It can also be defined as a physical method that uses a filter media with a complicated structure that only allows fluid to pass through to separate solid matter and liquid from a combination.
There are six types of filtration.
Vacuum filtrationCentrifugal filtrationGravity filtrationCold filtrationHot filtrationMultilayer filtrationMixture is defined as a substance that is composed of two more chemical compounds or substances that do not chemically mix.
There are two types of mixture.
Homogenous mixtureHeterogenous mixtureThus, pour the liquid through a paper filter made of rock salt mixture and let it filter, after complete filtration we obtain crystals of salt.
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How would you make the following compounds from N-benzylbenzamide?
a)dibenzylamine
b)benzoic acid
c)benzyl alcohol
Answer:
B.
Explanation:
What is metabolism? I know the answer.
Answer:
Metabolism is the set of life-sustaining chemical reactions in organisms. The three main purposes of metabolism are: the conversion of the energy in food to energy available to run cellular processes
Explanation:
How do we find the atomic size of an atom?
Answer:
The size of an atom can be estimated by measuring the distance between adjacent atoms in a covalent compound. The covalent radius of a chlorine atom, for example, is half the distance between the nuclei of the atoms in a Cl2 molecule.
Question 1 of 5
An atom's nucleus contains 8 particles that have no charge and 6 particles
that are positively charged. What is the atomic number of the atom?
A. 2
O
B. 8
C. 6
D. 14
SUBMIT
Answer:
C. 6
Explanation:
The atomic number of a number is related to the number of protons in the nucleus.
6. What is true about Calcium (Ca)?
A. It is a very unreactive metal.
B. It is reactive and is found with nonmetals in nature.
C. naturally uncombined with other elements.
D.It is a very reactive nonmetal.
Answer:
C. naturally uncombined with other elements.
Explanation: Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air.
What is difinition of chemistry
Why is the periodic table not arranged by atomic weight and instead arranged by atomic number?
At before Duberinor,Mendeleev tried to use atomic weight but they failed .
identify impacts of air pollution
Answer:
Air pollution can also cause headaches, dizziness, and nausea. ... Long-term health effects from air pollution include heart disease, lung cancer, and respiratory diseases such as emphysema. Air pollution can also cause long-term damage to people's nerves, brain, kidneys, liver, and other organs.
Explanation:
https://www.nationalgeographic.org/encyclopedia/air-pollution/#:~:text=Air%20pollution%20can%20also%20cause%20headaches%2C%20dizziness%2C%20and%20nausea.&text=Long%2Dterm%20health%20effects%20from,%2C%20liver%2C%20and%20other%20organs.
What is the angle between adjacent sp hybrid orbitals?
Answer:
180 degrees
Explanation:
sp hybridization generates orbitals that overlap linearly, generating a straight line. This leads to an angle measurement of 180 degrees.
Acetylene (C2H2) gas and oxygen (02) gas react to form carbon dioxide (CO2) gas and water (H20) vapor. Suppose you have 2.0 mol of C,H, and 1.0 mol
of o, in a reactor
Calculate the largest amount of CO, that could be produced. Round your answer to the nearest 0.1 mol.
The largest amount of CO₂ produced when 2 moles of C₂H₂ reacted with 1 mole of O₂ is 0.8 mole
We'll begin by writing the balanced equation for the reaction. This is given below:
2C₂H₂ + 5O₂ —> 4CO₂ + 2H₂O
2 : 5
2 : 1
From the balanced equation above,
We can see that O₂ is the limiting reactant as lesser amount of it is available.
Finally, we shall determine the largest amount of CO₂ produced by using the limiting reactant as illustrated below:
From the balanced equation above,
5 moles of O₂ reacted to produce 4 moles of CO₂.
Therefore,
1 mole of O₂ will react to produce = 4/5 = 0.8 mole of CO₂.
Thus, the largest amount of CO₂ produced from the reaction is 0.8 mole
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explain why an atom can only emit specific wavelengths of light and not every possible wavelength
Answer:
The electrons in an atom can only occupy certain allowed energy levels to a lower one, the excess energy is emitted as a photon of light, with its wavelength dependent on the change in electron energy. This is why an atom can only emit specific wavelengths of light and not every possible wavelength.
What is the Ideal level for chlorine in a spa?
Answer:
at least 3 ppm in hot tubs/spas
Explanation:
If the specific heat of Copper is 0.385 J/g °C and I add 10 kJ of heat to a 10kg block of copper, how much will the temperature of copper change?
a. 0.384 °C
b. 2.60 °C
c. 38.4 °C
d. 384 °C
e. more than 400°C
We have that for the Question "If the specific heat of Copper is 0.385 J/g °C and I add 10 kJ of heat to a 10kg block of copper, how much will the temperature of copper change?" it can be said that the temperature of copper change is
dt=2.60C
Option B
From the question we are told
If the specific heat of Copper is 0.385 J/g °C and I add 10 kJ of heat to a 10kg block of copper, how much will the temperature of copper change?
a. 0.384 °C
b. 2.60 °C
c. 38.4 °C
d. 384 °C
e. more than 400°C
Generally the equation for the Heat is mathematically given as
Q=Mcdt
Therefore
dt=\frac{1}{0.385}
dt=2.60C
Therefore
the temperature of copper change is
dt=2.60C
Option B
\
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A line can be used to represent a covalent bond between two atoms. Diagram pairs of atoms
that can form single, double, and triple bonds.
Can every atom form each of these kinds of bonds?
The covalent bond has been formed by the atom with the difference in the electronegativities and the presence of loan pair for an unsaturated bond.
The covalent bond has been formed between the atoms when there has been the sharing of electrons. The presence of loan pairs results in the formation of pi bonds, which are unsaturated covalent sharing formed above or below the covalent bonds.
An example of pair with a single bond has been:
H-HO-OThe examples of pairs with double bonds:
HHC=CHHC=OThe examples of pairs with triple bonds:
N [tex]\equiv[/tex] NHC [tex]\equiv[/tex] CHNot every atom can form these bonds as there has been the presence of loan pairs with the atom for the formation of the double and triple bond.
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During autumn, days grow colder. What happens to the nights?
They grow brighter.
They grow shorter.
They grow warmer.
They grow longer.
Answer:
I thinks its they grow longer explaination: I have a massive brain
Answer:
Brighter
Explanation:
3. Ethanol has a density of 0.800 g/mL.
a. What is the mass of 225 mL of ethanol?
Since the ethanol has a density of 0.800 g/mL, the mass of the ethanol is 180 grams.
Given the following data:
Volume of ethanol = 225 mLDensity of lead ball = 0.800 g/mL.To find the mass of the ethanol;
Density can be defined as mass all over the volume of an object.
Mathematically, the density of a substance is given by the formula;
[tex]Density = \frac{Mass}{Volume}[/tex]
Making mass the subject of formula, we have;
[tex]Mass = Density \times Volume[/tex]
Substituting the given parameters into the formula, we have;
Mass of ethanol = 180 grams.
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