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Related Questions
Help please! I’ll mark brainliest to who ever answers this first!!
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Answer:
paleontologists is the answer to scientist who studies fossil
Use the equation below to solve the problem that follows.
2H2 (g) + O2 (g) → 2H2O (g)
When David reacts 13.8 grams of hydrogen gas with excess oxygen, 87.0 grams of water are formed. Calculate his percent yield of water.
Im very loss with this question
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Percent yield of water : 70%
Further explanationReaction
2H₂ (g) + O₂ (g) → 2H₂O (g)
mol H₂(MW= 2 g/mol) :
[tex]\tt \dfrac{13.8~g}{2~g/mol}=6.9~mol[/tex]
mol H₂O = mol H₂ = 6.9
mass H₂O(theoretical) :
[tex]\tt 6.9\times 18~g/mol=124.2~g[/tex]
[tex]\tt \%yield=\dfrac{actual}{theoretical}\times 100\%\\\\\%yield=\dfrac{87}{124.2}\times 100\%=70\%[/tex]
Does the model correctly represent the electron dot diagram of magnesium? Why or why not? Check all that apply.
M g with 1 dot above and 1 right.
*{Yes, because the chemical symbol of magnesium is Mg.}
No, because the chemical symbol of magnesium is Mn.
*{Yes, because magnesium has two valence electrons.}
No, because magnesium has seven valence electrons.
No, because both of the dots should be on top of the chemical symbol
Answer 1 and 3
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Answer:
1 and 3
Explanation:
Answer: A and B or 1 and 3
Explanation:
8
Calcium carbonate (limestone) decomposes when heated.
Caco, + CaO + CO2
b) Calculate the volume of carbon dioxide produced if 10 grames were decomposed.
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Explanation:
Equation -
CaCO₃ → CaO + CO₂
molecular masses of -
CaCO₃ = 40+12+16×3 = 100 g/mol
CaO = 40+16 = 56 g/mol
CO₂ = 12+16×2 = 44 g/mol
Now,
If 100 g of CaCO₃ is decomposed then it produces 56 g of CaO and 44g of CO₂
Then,
If 1 g of CaCO₃ is decomposed then it produces 56/100g of CaO and 44/100g of CO₂
Now,
Here in question, 10g of CaCO₃ is decomposed
It means, It produces
56/100 × 10 = 56/10 = 5.6 g of CaO and
44/100 × 10 = 44/10 = 4.4 g of CO₂
Now,
we get that 10 g of CaCO₃ on burning produces 4.4 g of CO₂
we need to calculate volume of 4.4 g of CO₂
mole = mass/Gram molecular massThen,
mole = 4.4/44 = 0.1
Now,
volume = mole × 22.4 (in Litres)
= 0.1 × 22.4 = 2.24 L
Hence,
2.24 L of CO₂ will be produced when 10g of CaCO₃ decomposed.
A massless length of twine can withstand a maximum tension of 490 N. The twine is used to spin a 28-kg ball in horizontal circular motion of radius 1.8 m. The ball is spun faster and faster until the twine breaks. What was the maximum speed of the ball?
7.2 m/s
3.2 m/s
5.6 m/s
11 m/s
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Answer:
5.6 m/s
Explanation:
Why do electrons falling into different orbits give off characteristics wavelengths?
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Explanation:
Because the difference in energy between orbits is different in different types of atoms, moving electrons between different orbits requires photons carrying different amounts of energy (different wavelengths).
What makes the element oxygen different from the element hydrogen?
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Answer: the difference is due to the fact that one water molecule has two hydrogen atoms to one oxygen this means it takes two water molecules (2 H2O) to make one oxygen molecule (02) .At the same time however two molecules of water (2 H20) can make two molecules of hydrogen (2 H20)
Explanation: hope this helped and mark me as brainliest please =)
answer this pls thanks
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Answer: It is element nitrogen. It has an atomic number of 7 and the valence electron is 5. It needs 3 electrons to complete its octet state. That's why sometimes it has the oxidation number of -3 in ammonia.
What does the symbol △ in a chemical equation mean?
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Answer:
Delta, or subject to change.
Explanation:
Δ→ triangle indicates that the reaction is being heated.
What is a chemical equation?Chemical equations are symbolic representations of chemical reactions in which the reactants and the products are expressed in terms of their respective chemical formulae.
To express heating, we usually use Δ over reaction arrows like:
[tex]CaCO_ 3[/tex]. Δ → [tex]CaO+O_2.[/tex]
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Which of the following elements is a metalloid? A. phosphorus B. cobalt C. silicon D. magnesium
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Answer: silicon
Explanation:it just is
Respuesta
es la C. silicio
Explanation:
No existe una definición estandarizada de elemento metaloide ni un consenso completo sobre los elementos que son metaloides.
En la clasificación de metaloides se suelen incluir a:
Boro (B)
Silicio (Si)
Germanio (Ge)
Arsénico (As)
Antimonio (Sb)
Telurio (Te)
An object has a mass of 441 g and a volume
of 10 cm3. What is the density of the object
in g/cm3?
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The density is the ratio of the mass to the volume. The density of the object is 44.1 g/cm³.
What is density?Density (ρ) is the quantitative measurement of the substance having grams of mass that are dissolved per cubic meter of the solution. The density is calculated as:
ρ = M ÷ V
Given,
Mass of the object = 441 gm
The volume of the object = 10 cubic meter
Density is calculated as:
ρ = 441 ÷ 10
= 44.1 g/cm³
Therefore, 44.1 g/cm³ is the density of the object.
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Which of these describes a challenge that the engineer of a high-altitude
airplane would need to consider?
A. More fuel is used at higher altitudes.
B. The airplane may succumb to the power of gravity as lift
decreases at higher altitudes.
C. The airplane may need a heat shield for protection from sonic
booms.
O D. The airplane will create more drag at higher altitudes than lower
altitudes.
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Answer:
I think its (B)
Explanation:
as when the air thins out at higher elevations, your lift decreases so at some point, the plane cant produce enough lift to overcome gravity.
First person to comment there crush name get brainlyest
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Answer:
:0
Explanation:
David <3
whats the formula for mass
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Answer:
The unit of molar mass is kg/mol. Where, m = mass, v = velocity.
Hope that helps :)
Who knows the answer to this please help
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Carbon dioxide is formed by the given formula.
C(s)+O2(g)→CO2(g)
Carbon dioxide is
A
a compound of two elements, carbon and oxygen.
B
a mixture of two compounds, carbon and oxygen.
C
a compound of two atoms, carbon and oxygen.
D
an element of two atoms, carbon and oxygen.
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Answer:
A
Explanation:
Jeremiah pushed Anthony with a net force of 12 N. Anthony accelerated across the hall at 0.2 m/s2. What was Anthony’s mass?
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Answer:
6
Explanation:
Work Shown:
Force = Mass*Acceleration
F = ma
12 = m*0.2
12/0.2 = m
60 = m
m = 60 kilograms
Can somebody help me with this??!
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This is methane, Methane is gas that is found in small quantities in Earth's atmosphere. Methane is the simplest hydrocarbon,
consisting of one carbon atom and a powerful greenhouse gas. What is the chemical formula for methane?
A)
4CH
B)
C4H
C)
C4H4
D)
CH4
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Answer:
CH4
Explanation:
I looked it up and took the test
Answer:
You go to K12?
Explanation:
first to answer correctly gets brainleist! (you dont needa hear that vid thingy tahts just for ppl who cant read or need orial commidations or wtv lol)
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Answer:
The seasons are a result of the tilt of the earth
As water is cooled, its density increases until it reaches about
A. 4°C
B. 25°C
C. O'C
D. -2°C
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Which of the following describes the energy transformations that occur when a toaster is used to make toast?
Thermal energy is transformed into chemical energy in the toaster, and chemical energy is transformed into thermal energy in the toast.
Electrical energy is transformed into thermal energy in the toaster, and chemical energy is transformed into thermal energy in the toast.
Light energy is transformed into thermal energy in the toaster, and thermal energy is transformed into chemical energy in the toast.
Electrical energy is transformed into thermal energy in the toaster, and thermal energy is transformed into chemical energy in the toast.
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Answer:
Thermal energy (B)
Explanation:
just did it
Electrical energy is transformed into thermal energy in the toaster, and chemical energy is transformed into thermal energy in the toast. Hence option b is correct.
What is chemical energy?Chemical energy is defined as chemical substances' potential energy, which is released as they experience chemical reactions and change into other substances. Additionally, it is what binds a substance's molecule's together. The body transforms or changes the chemical energy in food into heat and mechanical motion.
The wire attached to the power source transmits electrical energy to the toaster. The heating element is a part of the toaster. This heating element transforms electrical energy into heat energy, which aids in toast preparation, when it comes into contact with it. Thus, with an electric toaster, electrical energy is converted to heat energy.
Thus, electrical energy is transformed into thermal energy in the toaster, and chemical energy is transformed into thermal energy in the toast. Hence option b is correct.
To learn more about chemical energy, refer to the link below:
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What is the concentration of a solution of 10. Moles of copper nitrate in 5.0 liters of solution
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Answer:
10.5
Explanation:
well we added together so thats the result
Need help ASAP!!please
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Someone answer these please! It’s multiple choice
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Answer: Number 1 is titanium.
The one where you calculate a tin block is 13.0cm.
3. Is A) Same Density And Same Chemical Properties.
4. Is also A. Ne
Explanation:
If the temperature of a substance increases will the particles of that substance be moving faster or slower or at the same speed as they were before the temperature changed
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Answer:
If the temperature increases, temperature reflects the speed of the molecules, so if the molecules are at a higher temperature, they are faster and they start to break bonds and new things react.
Explanation:
You can see protons yes or no
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No. Not with the naked eye
Colour in acid of red litmus paper
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Red
Litmus paper turn red when it comes in contact with acid. It turn blue if it come in contact with a base. Neutral litmus paper is purple
What is an atomic nucleus
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Answer:
The atomic nucleus is the small, dense region consisting of protons and net at the center of an atom.
Explanation:
The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden gold foil experiment. ... Protons and neutrons are bound together to form a nucleus by the nuclear force.
Answer:
The atomic nucleus is the small , dense region consisting of protons and neutrons at the center of an atom .
How does a longshore current change the beach
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Answer:
As this sheet of water moves on and off the beach, it can “capture” and transport beach sediment back out to sea. This process, known as “longshore drift,” can cause significant beach erosion.