what can scientists learn from index fossils?

Answer:

why

Explanation:

B is the answer to the question

Answer:

CaC

O

3

--------> CaO + C

O

2

20.7 g 6.81g +

As per the law of Conservation of mass , in any chemical reaction, the total mass of products is equal to the total mass of the reactants.

mass of C

O

2

+ mass of CaO is equal to the mass of CaC

O

3

.

mass of C

O

2

+ 6.81g = 20.7g

mass of C

O

2

= 20.7g- 6.81g = 13.89g

% yield of a Product Z = mass of product Z x 100 / mass of reactant

% yield of Product C

O

2

= 13.89 x 100 / 20.7 = 67. 10%

% yield of Product CaO = 6.81g x 100 /20.7 = 32.89%

Explanation:

:)

Answer:

Electron,Protons/Neutrons,Atom,Molecule

Explanation:

the answer is true the first one

Answer: Vibråtory movement.

Explanation: when particles bounce against each other the friction creates thermal energy. Think about what happens when you rub your hands together and they get warmer, that the friction between your hands making thermal energy.

Answer:

Option B. Single replacement reaction

Explanation:

To know which option is correct, it is important that we know the definition of each option. The definition of each option is given below:

1. Synthesis reaction is a reaction in which two different elements or compound combine together to produce a new compound different from the two starting elements or compound. An example is illustrated below:

C + D —> E

2. Single replacement reaction is a reaction in which an element replaces or displaces another element in a compound. An example is illustrated below:

D + BC —> B + CD

3. Combustion reaction is a reaction in a substance react with oxygen to generate carbon dioxide (CO₂) and water (H₂O). An example can be seen when organic compound react with oxygen to produce carbon dioxide (CO₂) and water (H₂O). This is illustrated below:

CₓHᵧ + (x + y/4) O₂ —> xCO₂ + (y/2) H₂O

4. Double replacement reaction is a reaction in which the ions of the two reacting compound replaces one another to form new products. This is illustrated below:

X⁺Y¯ + U⁺V¯ —> X⁺V¯ + U⁺Y¯

5. Decomposition reaction is a reaction in which a large compound breaks down into two or more elements or compound. An example is illustrated below:

GH —> G + H

Now, observing the equation given in the question above:

Sn + 2HCl —> SnCl₂ + H₂

We can see that Sn replaces H in HCl to produce SnCl₂.

Therefore, the reaction is a single replacement reaction.

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.

Answer:c

Explanation:

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

Answer:

I believe it is 1771 divided by 4

Explanation:

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.

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.

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.

For more details regarding ionic compounds, visit:

https://brainly.com/question/9167977

#SPJ2

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!

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.

The complete chemical formula for the unknown compound : N₂O₃

Given

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

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

Read more on https://brainly.com/question/21047043

Answer:

68

Explanation:

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sldjqkjqa

a

d

a

d

a

da

d

ad

ad

a

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

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:

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.

Answer:

Hey!

Explanation:

I dont know the answers but Cell walls and Cloroplasts are only in plant cells. I hope this helps!

Answer:

C = 18.29 g  

Explanation:

Given data:

Mass of beryllium needed = ?

Mass of nitrogen = 18.9 g

Solution:

Chemical equation:

3Be + N₂    →    Be₃N₂

now we will calculate the number of moles of nitrogen:

Number of moles = mass/molar mass

Number of moles = 18.9 g/ 28 g/mol

Number of moles = 0.675 mol

Now we will compare the moles of nitrogen and Be from balance chemical equation.

                     N₂        :       Be        

                       1          :       3

                  0.675       :      3/1×0.675 = 2.03 mol

Number of moles of Be needed are 2.03 mol.

Mass of Beryllium:

Mass = number of moles × molar mass

Mass = 2.03 mol ×   9.01 g/mol

Mass = 18.29 g  

Answer:

C. The gills allow the fish to take in oxygen from the water.

Answer:

Explanation:

HCl    + NaOH     =    NaCl    +     H₂O.

1 mole   1 mole           1 mole          1 mole

6.93  g of hydrochloric acid = 6.93 / 36.5 = .189 mole of HCl

2.4 g of NaOH = 2.4 / 40 =  .06 mole of NaOH

NaOH is in short supply so it is the limiting reagent .

1  mole of NaOH reacts with 1 mole of HCl to give 1 mole of Water

.06 mole of NaOH will react with .06 mole of HCl to give .06 mole of water

Water formed = .06 mole

= .06 x 18 = 1.08 g

= 1.1 g

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.

:)