Write a net ionic equation for the reaction that occurs when excess hydroiodic acid and nickel(II) sulfide are combined.
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Answer:

.5 kg

Explanation:

At the start of Uranium-235 there is a total of 1 kg. Uranium-235 half life is 700 million years, take 1kg ÷2 = 0.5kg after 1 half life.

Let's say another 700 million years go by that means you take 0.5kg and divide that by 2.

0.5kg÷2= 0.25 kg is left after 2 half lives.

Hope this helps good luck!

Answer:

the alteration of limestone by heat and pressure.

Explanation:

Answer:

YES :)

Explanation:

How does marble turn back into Limestone?

»MARBLE is a Metharopic rock formed by the alternation of Limestone by heat and pressure

»The calcite in the limestone changes and fosills and layering in the original limestone disappear as interlocking grains grow.

»If the limestone is pure ,a white marble is formed

Answer:

picture

Explanation:

i need the picture

we need a picture to

answer this sire

Answer:

the statement is a theory

Explanation:

mass of the sample gold= 38.6g

volume =

[tex]2 {cm}^{3} [/tex]

the density of the gold.

D = m/V

[tex]m = 38.6g[/tex]

[tex] = 0.0386kg[/tex]

[tex]v = 2 {cm}^{3} [/tex]

[tex] = 0.000002 {m}^{3} [/tex]

then substitute the values.

[tex]d = \frac{0.0386}{0.000002} [/tex]

[tex]d = 19300kg | {m}^{3} [/tex]

therefore, the density of the sample gold is 19300kg/m3

Answer:

formation of an ester by condensation

Explanation:

Edge 2022

Looking at the reaction sequence as described in the question, the ester can be said to be formed by condensation.

A condensation reaction is one in which a new compound is formed by the loss of a small molecule such as water from the two reacting compounds.

Looking at the reaction sequence as described in the question, the ester can be said to be formed by condensation. Hydrogen ion is lost from the first compound and -OH from the second one which is an instance of condensation.

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nebula

All stars start in a large cloud of dust and gas called a nebula. Gravity can pull some of the gas and dust in a nebula together, forming a proto-star. A star is born when the gas and dust from a nebula become so hot and dense that hydrogen atoms are smashed together to form helium.

hope this helps...

Answer:

  (d)  1,320

Explanation:

You want the product 55.78 × 23.7 rounded appropriately.

When a number has both an integer part and a decimal fraction, all of the digits are significant. Here, that means the first number has 4 significant figures, and the second number has 3 significant figures.

The number of significant figures in a product or quotient will be the least of the numbers of significant figures of the contributors. Here, the product can only have 3 significant figures.

  55.78 × 23.7 = 1321.986 ≈ 1320 . . . . rounded to 3 sf

Using the rules for significant figures, the answer is 1320.

__

Additional comment

Generally, the rules for significant figures apply to quantities derived from measurements. They can also be applied to estimates, where the result of computation using numbers of different precision cannot have any more accuracy than the least precise contributor.

The other useful rule in this process is that the rounding is saved for the final answer. Intermediate results should be carried to the full precision available.

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Answer:

1 kilogram of nuclear fuel

Explanation:

Answer:

1 Kilogram.

Explanation:

I took the test and I got an A. Really hope this helps you, friend!

Answer:

See below ~

Explanation:

#1

Here the functional group attached is OH(Alcohol) so we need to use -ol suffix

Right hand side is 2 carboned substituent i.e it's ethyl group

Hence the naming is

#2

Start numbering from alcohol towards left end .

The name is

#3

O is at centre and two methyl groups are branched both sides

#4

O is at centre,left side propane ,right side methane

#5

Left side ethane,Centred O,Right side methyl.

Answer:

Disagree carbon dioxide is one of the most important elements as it is present in nearly everywhere in our environment. We are also made from carbon. Carbon dioxide is present in our oceans. It is the most stable element in the periodic table therefore all element are compared to carbon-12 to calculate the relative mass of it from the element's isotopes. It is so important that a slight increase of CO2 production and other greenhouse gas production has the Earth become warmer causing it to have drastically impact our environment and also affecting our future.

In an ecosystem ,carbon dioxide is important so as to maintain the carbon foot prints.

Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.

Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.

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Answer:

There are 7 electrons in the nitrogen atom two in k shell and 5 in l shell

Explanation:

PLEASE MARK ME BRAINLIEST IF MY ANSWER IS CORRECT PLEASE

An ionic bond will be most likely formed between francium and chlorine having an electronegativity difference of 2.46.

An ionic bond is formed between to atoms that have a high difference in electronegativity between them. We now have to look out for the atoms that have a very high electronegativity difference. That pair is most likely to form an ionic bond.

Hence, an ionic bond will be most likely formed between francium and chlorine having an electronegativity difference of 2.46.

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Answer:

3.8 g

Explanation:

yan lng po maitutulong ko

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 2.34moles of potassium chloride will be produced from 175 g of potassium chlorate.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.

Mathematically,

mole =given mass ÷ molar mass

Molar mass of potassium chloride= 74.55 g/mol

Mass of potassium chloride= 175 g

Substituting the values in above formula we get

mole =175 g ÷  74.55 g/mol

moles of potassium chloride=2.34moles

Therefore, 2.34moles  of potassium chloride will be produced from 175 g of potassium chlorate.

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Answer:

Rate=k[N2O5]^2

Explanation:

It is more accurate to determine the rate law using experimental data instead of stoichiometry. The answer I just gave was derived from stoichiometry.

The correct expression for the rate of the reaction [tex]\rm 2N_2O_5(g) ---- > 4NO_2(g)[/tex]+ O2(g) is Rate = Δ[[tex]\rm N_2O_5[/tex]] / (2Δt). Therefore, the correct option is B.

In the chemical equation, 2 moles of [tex]\rm N_2O_5[/tex]result in 4 moles of [tex]\rm NO_2[/tex]. The rate expression for the reaction can be expressed on the basis of stoichiometry as follows:

Rate = -Δ[[tex]\rm N_2O_5[/tex]] / (2Δt)

Because of the stoichiometric coefficient of 2, this expression shows that the rate of reaction is equal to the rate of decomposition of [tex]\rm N_2O_5[/tex]divided by 2. Since [tex]\rm N_2O_5[/tex]is a reactant in the forward process, the negative sign means that its concentration is decreasing with time. ,

Therefore, the correct option is B.

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Your question is incomplete, most probably the complete question is:

For the reaction 2N2O5(g) → 4NO2(g) + O2(g) which of the following expressions is equal to the rate of the reaction?

A) Rate = -Δ[N2O5] / Δt

B) Rate = Δ[N2O5] / (2Δt)

C) Rate = -Δ[NO2] / Δt

D) Rate = Δ[NO2] / (4Δt)

Conversion of 3-cyclopentylbutanal to a carboxylic acid will be made possible through oxidation.

This is the process in a chemical reaction which involves the gain of oxygen atoms.

3-cyclopentyl butanal  is oxidized to carboxylic acids using potassium dichromate(VI) solution which turns green in the presence of dilute sulfuric acid.

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Answer:

Earth covers a greater area in position A than in position B in the same amount of time.

Explanation:

Based on the diagram that shows different positions of Earth and Mars around the sun, it seems that this statement is correct:

Earth covers a greater area in position A than in position B in the same amount of time. (Covers as I understood it means "overshadowing" Mars)

Answer:

.107 moles

Explanation:

To find moles given the info above, we use a variation of the Ideal Gas Law,

mol = PV/RT, where P is in atm, V is in L, T is in K, and R is the gas constant

mol= 3.47(.950) / 377(.08206)

For a gas containing 80% CH4 and 20% He is sent through a quart diffusion tube, the composition is mathematically given as

%He=12.5%

%CH4=87.5%

Generally, the equation for the Material balance  is mathematically given as

F=R+W

Therefore

100=0.20*1000+W

W=80kmol/min

In conclusion, waste gas compose

2.0/100*100=50/100*20+%*80

Hence

%He=12.5%

%CH4=87.5%

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the volume of ammonia produced at STP.

Mass of hydrogen is 32.6g

Molar mass of H2 = 2 g/mol

Moles of H = 32.6g/2g/mol = 16.3mol

N2(g) + 3H2(g) —-> 2NH3(g)

The Mole ratio of H to NH3 is 3 : 1

32.6 mole of H = 1/3 x 16.3= 10.87 mol = 5.43mol

Moles of NH3 = 5.43mol

At STP moles = volume/molar volume, but molar volume = 22.4L/mol

Moles = volume/molar volume, volume = moles X molar volume

Volume = 5.43 mol x 22.4L/mol

= 121.63 L

Volume of NH3 = 121.63L

The quantity of water in mL that was added to make the solution is 170 mL (option C)

M₁V₁ = M₂V₂

9 × 10 = 0.5 × V₂

90 = 0.5 × V₂

Divide both side by 0.5

V₂ = 90 / 0.5

V₂ = 180 mL

Volume of water added = V₂ – V₁

Volume of water added = 180 – 10

Volume of water added = 170 mL

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Explanation:

The number of moles of a substance is represented by the following formula:

n=NNA

where, n

is the number of moles of the substance, N

is the total number of molecules present in a substance, andNA

is the Avogadro constant.

The given compound is N2O5

So one mole of N2O5

contains 6.023×1023

numbers of molecules. Thus the 0.400

moles of N2O5

contains a number of molecules => 0.400moles×6.023×10^23

.

=> 2.41×10^23 molecules.

there are 2.41 thats the anwser

Answer:

28.0855 grams per mole

Answer:

When myocytes (aka muscle cells) are triggered at a certain point for awhile it can cause strain and pain throughout the muscle.

Answer:

B.6

Explanation:

Organism is at the top and does not get eaten by anything else. That is why I think the correct answer is b :)

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Answer:

Answer A  

Explanation:

2 H2  +  O2  = 2 H2O  

  knowing the mole weights of these elements shows O2 is the limiting reactant in this situation.

4 g oxygen is  4 /31.998  = .125 mole O2

  We should get two times these moles of water = .250 moles

         weight = .250 (1.008 * 2  + 15.999) =  4.50 gm H20   (theoretical)

   ....but we only got 4 gm

4/4.50  =  88.8%  

Answer:

H2(g) + F2(g) ----> 2HF(g)

Answer = F2

Given the data from the question, the number of aluminum atoms in aluminum oxide, Al₂O₃ is 2 (Option B)

From the formula of the compound, Al₂O₃ we see that the compound is composed of

From the above, we can conclude that Al₂O₃ contains 2 atoms of aluminum.

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