what can scientists learn from index fossils?
Answer:
dating and correlating the strata in which it is found
Explanation:
Answer:
The correct answer is A:The age of an unfamiliar layer of rock
Explanation:
I promise that I got it correct on A P E X <3
What is homologous series. write the example.
You have a 500.0 ml graduated cylinder filled with 100.0 mL of water. You carefully add a 178.5 gram piece of iron (density of iron = 7.87 g/mL). What is the final volume reading in the graduated cylinder after adding the iron piece?
Answer:
122.7 mL
Explanation:
Step 1: Given data
Volume of water: 100.0 mLMass of the piece iron (m): 178.5 gDensity of iron (ρ): 7.87 g/mLStep 2: Calculate the volume of the piece of iron
Density is equal to the mass of the piece divided by its volume.
ρ = m/V
V = m/ρ
V = 178.5 g/(7.87 g/mL) = 22.7 mL
Step 3: Calculate the volume of the mixture
The volume of the mixture is equal to the sum of the volume of water and the iron piece.
100.0 mL + 22.7 mL = 122.7 mL
A student determines the density of an unknown liquid by weighing a sample of known volume. The reported density is found by the instructor to be significantly higher than it should be. Which of the following experimental errors could account for this result?
A. The pipet used was filled to a level above the calibration mark.
B. The balance was read incorrectly, and the recorded sample mass was lower than the true sample mass.
or
C. A part of the sample was spilled from the beaker before it was weighed.
Answer: C. A part of the sample was spilled from the beaker before it was weighed.
Explanation:
Density is defined as the mass contained per unit volume.
[tex]Density=\frac{mass}{Volume}[/tex]
Density is directly related to mass and inversely related to volume. Thus if density is measured to be higher than it should be , it could be due to more mass or less volume.
Thus errors could be a part of the sample was spilled from the beaker before it was weighed.
The correct option is C. A part of the sample was spilled from the beaker before it was weighed.
The following information should be considered:
Density refers to the mass contained per unit volume.Density is directly related to mass and inversely related to volume.Learn more: https://brainly.com/question/4626564?referrer=searchResults
Weigh out the appropriate amount of HEPES sodium salt required to prepare 100 mL of a HEPES buffer that has pH 7.50 and is 90 mM in HEPES. FW for the HEPES sodium salt is 260.31. Transfer to a 150 mL beaker. Flowchart: Calculate the amount of HEPES sodium salt required to make the buffer.
Answer:
2.343 g of HEPES sodium salt is needed.
Explanation:
So, from the question above we have the following parameters which is going to help in solving this particular question.
The number of moles = 90mM, the pH = 7.50, FW for the HEPES sodium salt = 260.31, and the volume of HEPES sodium salt required = 100mL.
Therefore, the amount of HEPES sodium salt required to make the buffer = 260.31 × 9 × 0.001 = 2.343 grams of HEPES sodium salt is needed in 10mL.
What is the mollusk tongue called?
B
Answer:
why
Explanation:
B is the answer to the question
Select the structure that corresponds to the name:
Cyclohexanol
Answer:
Option "B" is correct answer ot the following question.
Explanation:
Cyclohexanol is a derivative that is alicyclic. It is manufactured industrial purposes from phenol through hydrolysis in the presence of catalysts of Ni/Al 2 O 3. It is also generated from cyclohexane in the existence of Co 3 O 4 nanocrystals through oxidation with organic molecules.
Jill graphs the speed of a model train that is travelling at a speed of 15 kilometers per hour. Which graph shows the speed of the model train?
Answer:c
Explanation:
How does the structure of gills in a fish enable it to live in a watery environment?
A. The gills allow the fish to take in carbon dioxide from the water.
B. The lungs of the fish are made up of tiny air sacs.
C. The gills allow the fish to take in oxygen from the water.
D. The villi absorb oxygen into the bloodstream.
Answer:
C. The gills allow the fish to take in oxygen from the water.
Anyone Free can help me with this question please ?
Answer:
68
Explanation:
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What is the formula for the ionic compound formed between sodium and oxygen?
Answer:
Na2O (the 2 is small the o is not a 0 but and OOh)
Explanation:
Hey there, The formula for the compound formed between sodium and oxygen will be Na2O
Though since sodium is a metal and oxygen is a nonmetal, Na2O is expected to be ionic.
What is an ionic compound?An ionic compound is a chemical compound made up of ions held together by electrostatic forces known as ionic bonding.
To determine an ionic compound's formula, first identify the cation and record its symbol and charge.
After that, identify the anion and record its symbol and charge. Finally, mix the two ions together to make an electrically neutral compound.
After two or more atoms lose or gain electrons to form an ion, an ionic bond can form.
Ionic bonds form when metals lose electrons and nonmetals gain electrons. Ions with opposite charges attract each other, forming an ionic bond.
The symbol for sodium is Na+, and the symbol for oxygen is O2. The resulting compound here in the given condition is Na2O.
Thus, this is the formula for the ionic compound formed between sodium and oxygen.
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Can I please get help with this question ♂️?
Answer:
1.50 moles of POH or Potassium Hydroxide.
Explanation:
First of all, find the substance formula
The substance formula of Potassium Hydroxide is
KOH
Second of all, if you want to convert from grams to moles, you use molar mass of KOH
Third of all, find the molar mass of KOH.
K = 39.1 amu
O = 16.0 amu
H= 1.0 amu
Potassium has 1 atom, oxygen has 1 atom, and hydrogen has 1 atom.
So do this:
39.1(1) + 16.0(1) + 1.0(1) = 56.1
The molar mass of KOH is 56.1 g/mol.
Fourth of all, use dimensional analysis to show your work.
84.20 grams of KOH * 1 mol/56.1 g/mol
The moles will cancel out.
84.20 divided by 56.1 = 1.500892166
But I have to round my answer to two digits after the decimal points instead of using sig figs.
So I round to the hundredths place
1.500892166 = 1.50
So the final answer is 1.50 moles(don't forget the units) of POH.
Hope it helped!
26. A Grignard's reagent may be made by
reacting magnesium with which of the
following compound ?
(A)
Methyl amine
(B) Diethyl ether
(C
)
Ethyl iodide
(D)
Ethyl alcohol
Can you give me the answers to questions 28 and 29 please?
28. unbalanced because in reactant side the Aluminium is 1 and oxygen is 2 but in the product side the Aluminium is 2 and oxygen is 3 it is not equal so it is unbalanced equation
29. unbalanced because the oxygen atom are not equal in the reactant and the product side
Follow me pls!!
atom ,molecule, proton neutron electron, elements/compounds from SMALLEST to the BIGGEST.
Answer:
Electron,Protons/Neutrons,Atom,Molecule
Explanation:
which soil would be the best for growing plants?
Honestly, its based on your preference but the best recommended one would be loam. I use loam too, and it is really good for growing the plants.
:)
Sulfur dioxide (SO2) is an unwelcome result
of burning soft coal in power plants. Some
of the SO2 ends up as sulfuric acid in acid
precipitation. The net reaction is
2 SO2(g) + O2(g) + 2 H2O(l) —— 2 H2SO4(l)
What mass in grams of SO2 is needed to
react with 1771 g of O2?
Answer in units of g.
Answer:
I believe it is 1771 divided by 4
Explanation:
A nucleus with four protons has total positive charge
4. What are the freezing and boiling points of water on the Fahrenheit scale? On the
Celsius scale?
What type of subatomic particles are found in the cloud?
A neutrons
B protons
C electrons
D croutons
Answer:
Electrons are particles that surround the nucleus of an atom like a cloud. As with protons and neutrons, electrons are essential to an atom's structure.
4. Naming Molecules
a) Describe how ionic bonds are formed at the atomic level.
Explanation:
Ionic bonds involve a cation and an anion. The bond is formed when an atom, typically a metal, loses an electron or electrons, and becomes a positive ion, or cation. Another atom, typically a non-metal, is able to acquire the electron(s) to become a negative ion, or anion.
An unknown compound has the following chemical formula: N2OX here stands for a whole number. Measurements also show that a certain sample of the unknown compound contains 4.00mol of oxygen and 2.67mol of nitrogen. Write the complete chemical formula for the unknown compound.
The complete chemical formula for the unknown compound : N₂O₃
Further explanationGiven
The chemical formula : N₂Oₓ
4.00 mol of oxygen and 2.67 mol of nitrogen
Required
The chemical formula
Solution
A molecular formula is a formula that shows the number of atomic elements that make up a compound.
The molecular formula of a compound shows the mole ratio of each of its constituent components
The mol ratio for N : O =
2.67 : 4 : divide by 2.67
1 : 1.5 = 2 : 3
A photon has an energy of 2.78 x 1032 J. What is its wavelength?
Answer:
7.14 × 10^(-58) m
Explanation:
We are given;
Energy; E = 2.78 x 10^(32) J
Formula to find this energy is;
E = hc/λ
Where;
E is energy
h is Planck's constant with a constant value of 6.62 × 10^(-34) J/s
c is speed of light with a constant value of 3 × 10^(8) m/s
λ is wavelength
Making λ the subject, we have;
λ = hc/E
λ = (6.62 × 10^(-34) × 3 × 10^(8))/(2.78 x 10^(32))
λ = 7.14 × 10^(-58) m
A sample of oxygen occupies a volume of 150 cm3 at 72 C. What will be volume of oxygen when the temperature drops to 2 C?
Answer:
V₂ = 119.59 cm³
Explanation:
Given data:
Initial volume = 150 cm³
Initial temperature = 72°C
Final volume = ?
Final temperature = 2°C
Solution:
Initial temperature = 72°C (72 +273.15 K = 345.15 K)
Final temperature = 2°C (2 + 273.15 k = 275.15 K)
Solution:
According to the Charles Law.
V₁/T₁ = V₂/T₂
V₁ = Initial volume
T₁ = Initial temperature
V₂ = Final volume
T₂ = Final temperature
Now we will put the values in formula.
V₁/T₁ = V₂/T₂
V₂ = V₁T₂/T₁
V₂ = 150 cm³ × 275.15 K /345.15 K
V₂ = 41272.5 cm³.K / 298 K
V₂ = 119.59 cm³
PLEASE HELP ASAP I NEED IT
the answer is true the first one
Which of these can be found in a plant cell, but not in an animal cell?
Answer:
Hey!
Explanation:
I dont know the answers but Cell walls and Cloroplasts are only in plant cells. I hope this helps!
Balanced equation for Co+O2=Co2O3
Answer:
4 Co(s) + 3 O2(g) = 2 Co2O3(s)
Explanation:
The balanced equation for Co+O₂=Co₂O₃ is Co+2O₂=Co₂O₃
In the equation balancing of Co+O₂=Co₂O₃ ,some points needs to be taken
which involves ensuring that the number of elements on the left hand side is
the same as that on the right hand side.
In this scenario, the number of carbon is the same on both sides but the
difference is in the number of moles of oxygen in which 2 is added to the left
hand side to make it balanced.
Co+2O₂=Co₂O₃
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Imagine an alternate universe where the value of the Planck constant is 6.6207 x 10^-36 J*s.
In that universe, which of the following objects would require quantum mechanics to describe, that is, would show both particle and wave properties? Which objects would act like everyday objects, and be adequately described by classical mechanics?
3.A turtle with a mass of 450. g, 29. cm long, moving at 2.7 cm/s.
quantum or classical?
Answer:
See explanation
Explanation:
According to Louis de Broglie, particles could exhibit wavelike properties and have an associated wavelength.
Now for a turtle with a mass of 450. g, 29. cm long, moving at 2.7 cm/s, recall that we can only describe a by quantum mechanics when the body is very small and its associated wavelength is large.
This object has a large mass, hence it is discussed by classical rather than quantum mechanics
B On At which point does the roller coaster have the most potential energy? and why?
Answer:
the first hill of the roller coaster
Explanation:
The first hill of a roller coaster is always the highest point of the roller coaster because friction and drag immediately begin robbing the car of energy. At the top of the first hill, a car's energy is almost entirely gravitational potential energy (because its velocity is zero or almost zero).
Answer:
top of the hill
Explanation:
A certain solid element is better electrical conductor than sulfur, but a poorer electrical conductor than copper. Which of the following elements is most consistent with this information.
a) germanium b) oxygen c) potassium d) mercury e) neon