50 points:


Several thousand years ago, people sought after the truth about the nature of matter by

Answer:

they would make up a population

Explanation:

all the inhabitants of a particular town, area, or country.

the population of frogs are very difficult to catch

Answer:

A compound

Explanation:

The water is best classified as a compound. When a substance is broken down into elemental composition or units, they are said to be a compound.

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).

Answer:

22.2 mol

Explanation:

Considering the reaction stoichiometry, 22.2 moles of Fe(OH)₂ are required to produce 7.4 moles of Fe₃(PO₄)₂.

The balanced reaction is:

3 Fe(OH)₂ + 2 H₃PO₄ → Fe₃(PO₄)₂ + 6 H₂O

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

Then you can apply the following rule of three:  if by reaction stoichiometry 1 mole of Fe₃(PO₄)₂ requires 3 moles of Fe(OH)₂, 7.4 moles of Fe₃(PO₄)₂ require how many moles of Fe(OH)₂?

[tex]amount of moles of Fe(OH)_{2} =\frac{7.4 moles of Fe_{3} (PO_{4} )_{2} x3moles of Fe(OH)_{2} }{1mole of Fe_{3} (PO_{4} )_{2} }[/tex]

amount of moles of Fe(OH)₂= 22.2 moles

Finally, 22.2 moles of Fe(OH)₂ are required to produce 7.4 moles of Fe₃(PO₄)₂.

Learn more:

Answer:

Chloride ion

Explanation:

The anion present in the unknown solution would be chloride ions.

A white precipitate of silver chloride is usually formed when drops of silver nitrate are added to a solution containing chloride ions. The ionic equation is as below:

    [tex]Cl^- (aq) + Ag^+ (aq) --> AgCl (s)[/tex]

Answer:

Boron Carbonate; B₂(CO₃)₃

Explanation:

For names, carbonide does not exist; that rules out the first option. Carbide refers to just a carbon atom, not carbon and oxygen as in the polyatomic ion carbonate. That rids us of the third option. We are left with boron carbonate with the formula BCO or boron carbonate with the formula B₂(CO₃)₃.

Recall the carbonate polyatomic ion's formula: CO₃²⁻

Thus BCO cannot be the formula.

Option 4 is your answer, Boron Carbonate; B₂(CO₃)₃.

To further check your answer, observe the oxidation states of boron and the polyatomic ion carbonate. Boron can exist in oxidation states of either 2+ or 3+, and carbonate is only 2-; in this formula, boron will exhibit a 3+ state to balance out with carbonate.

2x3+ = 6+; 3x2- = 6-

6+ + 6- = 0; balanced

Answer:

I'm gonna say A and B

Explanation:

Not sure though

Hope I helped :)

Answer:

The Kinetic energy decreases

Explanation:

because the speed of the molecules slows down.

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

Answer:

Air Temp 77F Dew-point 19F

Explanation:

Quiz

The dew point can be described as the temperature required by the air to be cooled. The driest air will have a higher dew point, therefore, at an air temperature of 66°F and a dew point of 60°F. Therefore, option (C) is correct.

The dew point can be defined as the temperature at which air should be cooled to become saturated with water vapor assuming constant air pressure and water content.

Moisture capacity will decrease below the dew point. Airborne water vapor will condense to form liquid water or dew. Dew develops on the surface and occurs through contact with a cooler surface.

The dew point is called the frost point when the temperature is below the freezing point because frost is produced by deposition rather than a condensation of water.

The humidity also impacts the dew point. The dew point increases when there is higher moisture in the atmosphere.  Therefore, the higher dew point refers to less humid air or drier.

To learn more about dew point, here:

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Answer:

Shrimp burrow

Explanation:

Shrimp are types of sea life, whales eat them

Answer:

1. anion

2. compund

3. ionic bond

4. polar molecule

5. molecule

6. covalent bond

7. cation

8. metallic bond

Explanation:

Answer: 2m/s.

Explanation: To find a speed/rate, you use the equation d = r*t. We switch around this equation to get r = d/t. Then, we plug in the numbers. r = 20 meters/10 seconds. Thus, the rate/speed is 2 meters/second (2m/s).

A man walks 20 meters in 10 seconds the speed is 2 meters per second (m/s).

Speed is something to measure the intensity of anything like any object which is moving from one place to another place and can be calculated by dividing the traveled distance by the time taken by the object.

To calculate the speed of man the given values are distance and time  20 meters in 10 seconds respectively.

                      speed = distance / time

substituting the value in equation,

               speed = 20/10  

               speed = 2 meter per second (m/s)

Therefore, a man walks 20 meters in 10 seconds the speed is 2 meters per second (m/s).

Learn more about speed, here:

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Answer:

false!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Explanation:

Answer:

6

Explanation:

Work Shown:

Force = Mass*Acceleration

F = ma

12 = m*0.2

12/0.2 = m

60 = m

m = 60 kilograms

definition physical  property  can be observed or measured without changing the composition of matter

examples

color

density

volume

mass

definition

chemical A chemical property is a characteristic of a particular substance that can be observed in a chemical reaction. Some major chemical properties include flammability, toxicity, heat of combustion

examples flammability, toxicity, acidity, reactivity

pretty much the difference is is that chemical changes its chemical reaction involving the rearrangement of the atoms of one or more substances and a change in their chemical properties or composition, resulting in the formation of at least one new substance Physical change does not do that

Answer:

5.6 m/s

Explanation:

Answer: The element is sulfur and the atomic mass is 32.07

Explanation: wasn’t sure what you were asking so gave you both

Convection currents are flowing fluid that is moving because there is a temperature or density difference within the material. ... A temperature difference leads to an energy transfer from an area of higher energy to one of lower energy. Convection is a heat transfer process.

Answer:

80mg

Explanation:

Given parameters:

Density of Platinum metal = 21.4g/mL

Dimension of the metal  = 3cm by 0.03m by 40mm

Unknown:

Weight of the metal in milligrams?

Solution:

Density is the mass per unit volume of a substance.

Mathematically;

          Density  = [tex]\frac{mass}{volume}[/tex]

Volume of the platinum metal  = l x w x h

 Let us convert the dimension of the metal to the same unit;

            3cm x 0.03m x 40mm

    convert to cm;

           100m = 1cm

           0.03m  = [tex]\frac{0.03}{100}[/tex]   = 0.0003cm

     -- 40mm;

            1mm = 0.1cm

           40mm  = 40 x 0.1  = 4cm

Volume of the metal  = 3 x 0.0003 x 4  = 0.0036cm³

1mL = 1cm³; so volume  = 0.0036mL

     Mass of the metal  = 21.4 x 0.0036  = 0.08g

       1g  = 1000mg

     0.08g  = 0.08 x 1000 = 80mg

Answer:

d

Explanation:

the reason is you have Cu S and O

Answer:

mutualism,commensalism and parasitism

Answer:

mutualism, commensalism, and parasitism

Answer:

CH4

Explanation:

I looked it up and took the test

Answer:

You go to K12?

Explanation:

Answer:"You can change an object's state of matter by adding or removing thermal energy. When you add thermal energy to an object, these things can happen: Particles move faster (increased kinetic energy). Particles get farther apart (increased potential energy)."

Explanation:

Answer:

far left

Explanation:

No. Not with the naked eye