Help! What is this question I do not understand

the first one is A covalent bond.

the second one is Answer: B Decomposition

Answer:

A. Dalton's model

Explanation:

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

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[tex]\small\sf\:\:\:\:\:\:\:\:{:}\:\Longrightarrow{\bold{\pink{\sf{Thomson's \:model}}}}[/tex]

Answer:

ok so i did the problem and the answer was 8e+29

Explanation:

i dont really know what the answer is but thats the answer i got

sorry if this didnt help

Answer:

the theoretical 100% yield of the product in milligrams is 302920 mg

Explanation:  

Given the data in the question;  

245 mg of an oil

Using the moles of our protected aldehyde calculated earlier (2.96)

the molecular weight of the product (102 g/mol) = 102000 mg/mol

so, the mass of aldehyde produced (100% yield) will be;

⇒ number of moles × molar mass

⇒ 2.96 mol × 102000 mg/mol

⇒ 302920 mol.mg / mol

⇒ 302920 mg

Therefore, the theoretical 100% yield of the product in milligrams is 302920 mg

Answer:

B

Explanation:

A isnt correct because animals have no emotions

C isnt correct because animals dont sleep all day

D isnt correct because not all organisms can swim or fly

B makes the most sense

Answer:

B) A control group is used for comparison to other groups.

E) A controlled experiment must have a control group and test group(s).

Explanation:

Answer:

B & E should be the answers

Answer:

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

Answer:

See explanation

Explanation:

In writing a chemical reaction equation, we must ensure that it is balanced. In a balanced chemical reaction equation, the number of atoms of each element on the left hand side of the reaction equation must be equal to the number of atoms of the same atom on the right hand side of the reaction equation.

Let us now consider the reaction of NaOH with water as follows;

2Na(s) + 2H2O(l) ------> 2NaOH(aq) + H2(g)

For the reaction of Magnesium metal and HCl we have;

Mg(s) + 2HCl(aq) -------> MgCl2(aq) + H2(g)

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:

130!!

Explanation:

Answer:

Nacl compound contain ionic bonds because sodium is metal and chlorin is nonmetal

Answer:

Kc = 1.09x10⁻⁴

Explanation:

HF = 1.62g

H₂O = 516g

F⁻ = 0.163g

H₃O⁺ = 0.110g

To solve this question we need to find the moles of each reactant in order to solve the molar concentration of each reactan and replacing in the Kc expression. For the reaction, the Kc is:

Kc = [H₃O⁺] [F⁻] / [HF]

Because Kc is defined as the ratio between concentrations of products over reactants powered to its reaction coefficient. Pure liquids as water are not taken into account in Kc expression:

[H₃O⁺] = 0.110g * (1mol /19.01g) = 0.00579moles / 5.6L = 1.03x10⁻³M

[F⁻] = 0.163g * (1mol /19.0g) = 0.00858moles / 5.6L = 1.53x10⁻³M

[HF] = 1.62g * (1mol /20g) = 0.081moles / 5.6L = 0.0145M

Kc = [1.03x10⁻³M] [1.53x10⁻³M] / [0.0145M]

Answer:

I think the answer is probably b

Answer:

1 Ca3(PO4)2+ 6 NaCl ---------> 2 Na3PO4 + 3 CaCl2

Answer:

I think the answer is X

Explanation:

X is a variable and variables stand for the unknown

Answer:

A fluke because it is an vertebrae

Explanation:

Answer:

Question: what is the purpose of ash to soil conditioning?

answer: soil conditioner is a product that is added to soil to improve the soils physical qualities, it's usually the fertility of the soil and sometimes the mechanics of the soil. can be used to improve poor soils.

most wood ash contains a good percentage, about 25 percent, of calcium carbonate, which is an ingredient in garden lime. if your soil is highly acidic, with a pH of 5.5 or lower, amending with wood ash can raise the pH of your soil.

Answer:

Explanation:

C

2.00 M is the molarity of a solution made by dissolving 1.25 mol of HCl in enough water to make 625 mL of solution.

A mole is defined as 6.02214076 ×  of some chemical unit, be it atoms, molecules, ions, or others. The mole is a convenient unit to use because of the great number of atoms, molecules, or others in any substance.

[tex]Molality = \frac{Moles \;solute}{Volume \;of \;solution \;in \;litre}[/tex]

[tex]Molality = \frac{1.25}{0.625}[/tex]

Molality = 2.00 M

Learn more about moles here:

brainly.com/question/8455949

#SPJ2

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:

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:

A. It explains how nature works.

Explanation:

A scientific theory is an explanation, based on a body of evidence, of how something works or will behave.

The other three answers contradict scientific theory. Theories should be based on many experiments, and you should be able to replicate the results and observations.  

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:

Blood fractionation is the process of fractionating whole blood, or separating it into its component parts. This is typically done by centrifuging the blood. The resulting components are: a clear solution of blood plasma in the upper phase (which can be separated into its own fractions, see Blood plasma fractionation),

Answer: Centrifugal force is used to separate the components of blood – red blood cells, platelets and plasma – from each other. ... The red blood cells precipitate to the bottom of the bag, with the platelets above them, then the white blood cells and the plasma at the very top. Also because Each part of the blood has a different function. Separating the blood into parts lets patients get only the specific part or parts of the blood that they need. So a whole blood donation can be used for several patients.

Hope this helps have a awesome day/nigh❤️✨t

Explanation:

Answer:

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