Pls help me over here

Answer:

A. Dalton's model

Explanation:

Dalton's model was discarded as a result of Rutherford's model.

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Answer:

A fluke because it is an vertebrae

Explanation:

Answer:

Ionic bond

CaO is an ionic bond. Two-element compounds are usually ionic when one element is a metal and the other is a non-metal. It is made up of one metal ion/cation(Ca^2+) and an non-metal ion/anion(O^2-).

Answer:

A. in which oxidation numbers change

Explanation:

This is because in oxidation reduction reactions or redox reactions, involves the sharing or transfer of electrons between species and the oxidation numbers changes. There is change in electrons, ions or oxidation number by gaining or lossing electrons. Increase in oxidation number is an indication of oxidation while decrease in oxidation indicate reduction.

Answer:

Classification is important because it allows scientists to identify, group, and properly name organisms via a standardized system (Linnaeus Taxonomy); based on similarities found in the organisms DNA/RNA (genetics), Adaptations (Evolution), and Embryonic development (Embryology) to other known organisms to better.

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The five kingdoms of classifications were animalia, plant, fungi, protista and monera. Later Archaebacteria was discovered and this led to the 3 kingdom classification animalia, plantae and protista.

There are different classifications for living things based on their nature, body and origin. The kingdom animalia includes  all the animals including human beings.

Kingdom plante includes all the plants and kingdom fungi, protista and monera are of microbes. Later the discovery and study of Archaebacteria proved that they exhibit similar body type and functions as bacterias.

After that, scientists turned into 3 kingdom classification, where all the prokaryotic organisms including protists, monera and fungi classified as one. The evolutional changes originated in them made this classification.

To find more on biological classification, refer here:

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Answer:

The bones of the skull and spinal column

Explanation:

The central nervous system is better protected than any other system or organ in the body. Its main line of defense is the bones of the skull and spinal column, which create a hard physical barrier to injury.

Answer:

The Central Nervous System (CNS)

D. Matter and energy are the same.

Answer:

130!!

Explanation:

Answer:

2. Argon at 160K and approximately 6 atm pressure

5. Neon at 50K and approximately 10 atm pressure

6. Water at 894 K and approximately 20 atm pressure

8. Oxygen at 194K and approximately 2 atm pressure

Explanation:

Super critical fluid is formed when temperature rises beyond critical point. The state of molecules can be liquid or gas. The pressure should be above the certain level with an introduction of different gases at minimum of 2 atm pressure.

the answer is : False

just did it

Answer:

d

Explanation:

Answer:

hopen it helps soo much thanks for the points

Answer:

In nuclear fission, an unstable atom splits into two or more smaller pieces that are more stable, and releases energy in the process. The fission process also releases extra neutrons, which can then split additional atoms, resulting in a chain reaction that releases a lot of energy.

Explanation:

Answer:

3 grams??

Explanation:

I think this would be the answer you are looking for.

The rate of effusion of Argon here is 8.03 min

Data;

This law states that the rate of effusion of a gas is inversely proportional to the square root of it's molar mass.

[tex]R \alpha \frac{1}{\sqrt{M} }[/tex]

From this,

[tex]\frac{r_1}{r_2} = \frac{\sqrt{M_2} }{M_1}[/tex]

substituting the values and solving,

[tex]\frac{R_A_r}{12.7}= \frac{\sqrt{16} }{\sqrt{40} } \\ R_A_r = \frac{12.7*\sqrt{16} }{\sqrt{40} } \\R_A_r = 8.032min[/tex]

The rate of effusion of Argon here is 8.03 min

Learn more on Graham's law of effusion here;

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Answer:

when the valence (outermost) electrons of one atom are transferred permanently to another atom

Answer:

[tex]5.77x10^{47}particles.[/tex]

Explanation:

Hello!

In this case, since we are given 9.58x10²³ moles of potassium sulfate, it is possible to compute the particles according to the Avogadro's number:

6.022x10²³

As shown below:

[tex]9.58x10^{23}mol*\frac{6.022x10^{23}}{1mol}\\\\5.77x10^{47}particles.[/tex]

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Answer:

A molecule of oxygen breaks into two atoms of oxygen showing that the bond is being broken. When bonds break, energy is absorbed and when bonds are formed energy is released. Hence, the answer to this question is (A).

Explanation:

Answer:

0.856

Explanation:

Given data:

Feed molar rate ( Fao ) = 10 mol/min

Feed concentration ( Cao ) = 0.4 mol/dm^3

current conversion rate = 80%  

Temperature = 305 K

catalyst = 100 kg

entering pressure = 20 atm

exit pressure = 2 atm

Determine the conversion if the catalyst particle size were doubled and everything else remained the same

The conversion if the catalyst particle size were doubled and other factors remains the same = 0.856

attached below is a detailed solution

Answer: https://brainly.com/question/2426371

Explanation: Someone already answered this, click the link. YW! :))

Answer:

The chemical compound Mg(NO3)2, also known as magnesium nitrate, is very soluble, especially in water.

Answer:

1.4×10⁸ g of CaO

Explanation:

We'll begin by converting 250 tonnes to grams (g). This can be obtained as follow:

1 tonne = 1×10⁶ g

Therefore,

250 tonne = 250 × 1×10⁶

250 tonne = 2.5×10⁸ g

Next, the balanced equation for the reaction.

CaCO₃ —> CaO + CO₂

Next, we shall determine the mass of CaCO₃ that decomposed and the mass CaO produced from the balanced equation. This can be obtained as follow:

Molar mass of CaCO₃ = 40 + 12 + (16×3)

= 40 + 12 + 48

= 100 g/mol

Mass of CaCO₃ from the balanced equation = 1 × 100 = 100 g

Molar mass of CaO = 40 + 16

= 56 g/mol

Mass of CaO from the balanced equation = 1 × 56 = 56 g

SUMMARY:

From the balanced equation above,

100 g of CaCO₃ decomposed to produce 56 g of CaO.

Finally, we shall determine the mass of CaO produced by the decomposition of 250 tonnes (i.e 2.5×10⁸ g) of CaCO₃. This can be obtained as follow:

From the balanced equation above,

100 g of CaCO₃ decomposed to produce 56 g of CaO.

Therefore, 2.5×10⁸ g of CaCO₃ will decompose to produce =

(2.5×10⁸ × 56)/100 = 1.4×10⁸ g of CaO.

Thus, 1.4×10⁸ g of CaO will be obtained from 250 tonnes (i.e 2.5×10⁸ g) of CaCO₃.

Answer:

Overall enthalpy change for the formation of one mole nitric acid from nitrogen, hydrogen and oxygen, ΔH = -376 KJ

Note: the question is incomplete. The complete question is given below:

Nitric acid can be formed in two steps from the atmospheric gases nitrogen and oxygen, plus hydrogen prepared by reforming natural gas. In the first step, nitrogen and hydrogen react to form ammonia: N₂(g) + 3H₂(g)  → 2NH₃(g) ΔH = -92. kJ In the second step, ammonia and oxygen react to form nitric acid and water: NH3(g) + 2O2(g) → HNO3(g) + H2O(g) ΔH = -330. kJ Calculate the net change in enthalpy for the formation of one mole of nitric acid from nitrogen, hydrogen and oxygen from these reactions. Round your answer to the nearest kJ.

Explanation:

From Hess's law of constant heat summation, the total enthalpy change for a reaction is the sum of all changes without regard to the number of multiple stages or steps involved in a reaction.

Enthalpy is a state function as it does not depend on the path taken to attain its value. Therefore, the summation of the enthalpy changes involved in the individual steps in the reaction of the formation of nitric acid will be equal to the enthalpy change of the overall reaction step.

For the first reaction step:

N₂(g) + 3H₂(g)  →  2NH₃(g) ΔH = -92. kJ

For the second reaction step:

NH₃(g) + 2O₂(g) → HNO3(g) + H2O(g) ΔH = -330. kJ

Overall reaction step:

[tex]\frac{1}{2}[/tex]N₂(g) + [tex]\frac{3}{2}[/tex]H₂(g) + 2O₂(g)  →  HNO₃ + H₂O  ΔH = ?

The overall reaction for the formation of one mole of nitric acid from nitrogen, hydrogen and oxygen shows that the first reaction step should be divided by 2

[tex]\frac{1}{2}[/tex]N₂(g) + [tex]\frac{3}{2}[/tex]3H₂(g)  →  NH₃(g) ΔH = -46. kJ

Overall enthalpy change, ΔH = ΔH₁ + ΔH₂

Overall enthalpy change,ΔH = (-46 KJ) + (-330 KJ)

Overall enthalpy change,ΔH = -376 KJ

Answer: 3.5 moles of hydrogen gas will be produced.

Explanation:

The balanced chemical equation is:

[tex]2Fe+6HCl\rightarrow 2FeCl_3+3H_2[/tex]

As HCl gets completely used up, [tex]HCl[/tex] is the limiting reagent.

According to stoichiometry :

6 moles of [tex]HCl[/tex] produces =  3 moles of [tex]H_2[/tex]

Thus 7.0 moles of  [tex]HCl[/tex] produces=[tex]\frac{3}{6}\times 7.0=3.5moles[/tex]  of [tex]H_2[/tex]

 Thus 3.5 moles of hydrogen gas will be produced.

Answer:

Volume of bacteria cell into Pico liters = 60.27 Pico liters

Explanation:

Given:

Volume of bacteria cell = 6.027 x 10⁻¹⁰ L

Find:

Volume of bacteria cell into Pico liters

Computation:

1 L = 10¹² Pico liters

So,

Volume of bacteria cell = 6.027 x 10⁻¹⁰ L

Volume of bacteria cell = 6.027 x 10⁻¹⁰ x 10¹² Pico liters

Volume of bacteria cell into Pico liters = 60.27 Pico liters