What type of change goes on inside when a glow stick is activated?

Chemical
Physical
Both

Answer Is Any Real Numbers, Such As 6,15,21.

If 170 milligrams of a radioactive substance decays to 85 g after 16 hours. Then, after 21 hours, approximately 75.2 mg of the radioactive substance will remain.

The decay of the radioactive substance follows an exponential decay equation of the form:

\(N(t) = N_{o} \times e^{-kt}\)

Where:

N(t) is the amount of substance remaining at time t

N₀ is the initial amount of substance

k is the decay constant

t is the time elapsed

Given to us is N₀ = 170 mg and N(16) = 85 mg. We can use this information to find the decay constant, k.

\(85 = 170 \times e^{-k \times 16}\)

Dividing both sides by 170:

\(0.5 = e^{-k \times 16}\)

To solve for k, we can take the natural logarithm (ln) of both sides:

ln(0.5) = -k × 16

from this, the value of k comes out to be:

k = 0.0431

Now we can use the decay equation to find the amount of substance remaining after 21 hours, N(21):

\(N(21) = 170 \times e^{-0.0431 \times 21}\)

Calculating this expression:

N(21) = 75.2

Therefore, after 21 hours, approximately 75.2 mg of the radioactive substance will remain.

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Answer:

yes

Explanation:

Answer:

Lead

Explanation:

While taking sample from flint's distillery, theybfoind 13000 ppb or parts per billion lead in the water itself

The standard reduction potential for the half-reaction of Be^2+ + 2e^- -> Be is given as E^0 = 3.83 V.

For the half-cell Hg^2+ | Hg, the standard reduction potential is not provided in the given information. To calculate the electric potential for the voltaic cell, we need the reduction potential for the Hg^2+ | Hg half-cell.

A voltaic cell, also known as a galvanic cell or an electrochemical cell, is an electrochemical device that generates electrical energy through a spontaneous chemical reaction. It consists of two half-cells connected by an external circuit and a salt bridge or porous barrier that allows the flow of ions between the two half-cells.

Each half-cell consists of an electrode immersed in an electrolyte solution. The electrode is typically made of a metal or a conductive material, and the electrolyte is a solution containing ions that can participate in the redox (reduction-oxidation) reaction.

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The correct order of the steps in the scientific method is as follows:

Ask questions: The first step in the scientific method is to ask a question about something you observe in the world around you. For example, you might ask "Why do leaves change color in the fall?"

Make observations: The next step is to make observations about the thing you are interested in. In this case, you might observe the leaves on a tree and notice that they are changing color.

Construct a hypothesis: A hypothesis is a possible explanation for something you observe. In this case, you might hypothesize that leaves change color in the fall because the days are getting shorter.

Test the hypothesis with an investigation: The next step is to test your hypothesis by doing an investigation. In this case, you might set up an experiment to see if the amount of sunlight affects the color of leaves.

Analyze the data: Once you have done your investigation, you need to analyze the data to see if it supports your hypothesis. In this case, you might look at the color of the leaves on different trees at different times of the year.

Explain the results: Once you have analyzed the data, you need to explain the results. In this case, you might explain that the leaves change color in the fall because the days are getting shorter.

Communicate the results: The final step is to communicate the results of your investigation to others. In this case, you might write a report about your findings or give a presentation to your class.

Repeat the process: The scientific method is an iterative process, which means that you can repeat it as many times as you need to. In this case, you might repeat your experiment to see if you get the same results. You might also modify your experiment to see if you can get different results.

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Answer:

Scientific Notation: 2.503 × 10⁶

Standard Form: 2,503,000

Hey there!

\(\mathsf{(3 \times 10^3) + (2.5 \times 10^6)}\)

\(\mathsf{= 3 \times 10^3 + 2.5 \times10^6}\)

\(\mathsf{10^3}\)

\(\mathsf{= 10 \times 10 \times 10}\)

\(\mathsf{= 100 \times 10}\)

\(\mathsf{\bf = 1,000}\)

\(\mathsf{10^6}\)

\(\mathsf{= 10 \times 10 \times 10 \times 10 \times 10 \times 10}\)

\(\mathsf{= 100 \times100 \times100}\)

\(\mathsf{= 10,000\times100}\)

\(\mathsf{= \bf 1,000,000}\)

\(\mathsf{= 3\times 1,000 + 2.5 \times 1,000,000}\)

\(\mathsf{3\times1,000}\)

\(\mathsf{\bf = 3,000}\)

\(\mathsf{2.5 \times 1,000,000}\)

\(\mathsf{\bf = 2,500,000}\)

\(\mathsf{3,000 + 2,500,000}\)

\(\mathsf{= \bf 2,503,000}\)

\(\boxed{\boxed{\large\textsf{Answer: } \mathsf{ \bf 2,503,000 \ or \ 2.503 \times 10^6}}}\huge\checkmark\)

\(\large\textsf{Good luck on your assignment and enjoy your day!}\)

~\(\frak{Amphitrite1040:)}\)

Answer:

Maybe try a Course Outline or talk to a professional for advice.

Explanation:

Answer:

waste energy = 30 J

Explanation:

Given that.

Input energy = 100 J

Useful energy = 70 J

We need to find the amount of waste energy.

Waste energy = total energy - used energy

= 100 J - 70 J

= 30 J

Hence, 30 J of energy is waste energy.

The order of 1 indicates that the rate of the reaction is directly proportional to the concentration of reactant 'a'.

The order of the reaction with respect to the reactant 'a' can be determined by examining the rate law equation. In this case, the rate law is given as rate = [a][b][c], where [a], [b], and [c] represent the concentrations of reactants 'a', 'b', and 'c', respectively.The order of the reaction with respect to a particular reactant is determined by the exponent to which the concentration of that reactant is raised in the rate law equation. In this case, since the rate law equation includes only [a] without any exponent specified, we can conclude that the order of the reaction with respect to reactant 'a' is 1.The order of 1 indicates that the rate of the reaction is directly proportional to the concentration of reactant 'a'. This means that if the concentration of 'a' is doubled, the rate of the reaction will also double. If the concentration of 'a' is halved, the rate will be halved.It is important to note that the order of the reaction with respect to a particular reactant can only be determined experimentally by conducting multiple experiments and analyzing the effect of changing the concentration of that specific reactant on the rate of the reaction. The rate law equation provides valuable information about the order of the reaction with respect to each reactant.

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Answer:

5.40 moles ( to 3 signif digits )

Explanation:

ONE mole is Avagadro's Number   6.022 x 10^23  atoms/mole

3.25 x 10^24 atoms / (6.022 x10^23 atoms/mole ) = 5.396 moles ~ 5.40 moles

A 1.60 g tablet is found to contain 0.0133 mol of the amino acid glycine (C₂H₅NO₂). (The molar mass of C₂H₅NO₂ is 75.07 g/mol.). So the mass percent of C₂H₅NO₂ in the tablet is 62.4%.

To find the mass percent, one needs to first determine the mass of C₂H₅NO₂ in the tablet. One can do this using the molar mass of C₂H₅NO₂, which is given as 75.07 g/mol in the question.

The molar mass of C₂H₅NO₂ is 75.07 g/mol, so the mass of 0.0133 mol of C₂H₅NO₂ is:

0.0133 mol x 75.07 g/mol = 0.998 g

Therefore, the mass percent of C₂H₅NO₂ in the tablet is:

(0.998 g / 1.60 g) x 100% = 62.4%

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Answer:

Nitrites can be reduced to form nitrogen. Almost all nitrate salts are soluble in water. Almost nitrate are soluble in water and slightly soluble in primary alcohols. The oxidation number of nitrogen in the nitrates is +5. The oxidation number of nitrogen in nitrates is +3.

Explanation:

Ammonium nitrate readily dissolves in water by dissociating into its respective ions. This salt is acidic in nature. Ammonium nitrate is an important fertilizer required for the growth of plants.

The nitrogen is the most usually used limiting supplement in the development of crops. Nitrogen is essential for the vegetative development and it is involved in creating food through photosynthesis. The use of ammonium nitrate is the best way to provide nitrogen for the plants.

It is very essential to convert nitrogen into nitrate, in order to be used by the plants. The ammonium nitrate and nitrite are highly stable than urea and does not rapidly lose nitrogen to the atmosphere. So both the nitrites and nitrates of ammonium are soluble in water and plants can easily absorb them.

So ammonium nitrate has high nutrient content.

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The kinetic energy of the electron be, in j is 4.1766 × 10⁴⁹.

Kinetic energy is the power an object has because of its motion. If we want to boost up an object, then we must follow a force. making use of force requires us to do paintings. After work has been accomplished, energy has been transferred to the object, and the object might be moving with a new consistent speed.

Calculation:-

wavelength = 189.1 nm

                   = 189.1 × 10⁻⁹ m

c = λf

f  =  189.1 × 10⁻⁹ m / 3 × 10⁸

   = 63.033  × ⁻ ¹⁷

kinetic energy = hf

                         = 6.626 × 10⁻³⁴ ×  63.033  × ⁻ ¹⁷

                         = 417.66 × 10⁻⁵¹

                          = 4.1766 × 10⁴⁹

The kinetic energy of an item is the electricity that it possesses because of its motion. it is defined because the work needed to boost up a frame of a given mass from relaxation to its stated pace. Having gained this energy for the duration of its acceleration, the frame maintains this kinetic electricity except for its pace changes.

Potential energy saved energy that relies upon the relative position of numerous components of a gadget. A spring has greater potential energy when it is compressed or stretched. A steel ball has extra capability strength raised above the ground than it has after falling to Earth.

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Answer:

3:46 pm

Explanation:

Answer:

8:47 p.m

Explanation:

Answer:

Ethanol

Explanation:

All four of these compounds are organic chemicals that occupy the capacity to withhold different intermolecular forces, commonly known as bonds. There are three main types of intermolecular forces, called London Dispersion, dipole dipole, and hydrogen bonding.

Hydrogen bonds are a different kind of dipole dipole bonding that is relatively strong and involves an electronegative atom (only Nitrogen, Oxygen, and Fluorine) causing a force of attraction with a Hydrogen.

Hydrogen bonds are created when there are partial positive charge on the Hydrogen atom, and a partial negative charge on the electronegative atom.

In other words, we are looking for a Hydrogen attached to a Nitrogen, Oxygen, or Fluorine.

◾ Ethanol's structure:                                                 \(\\~~~~~~~H~~~~H\\~~~~~~~~|~~~~~|\\H-C-C-O-H\\~~~~~~~~|~~~~~|\\~~~~~~~H~~~~H\\\)

      → A clear hydroxyl group (O-H) at the right hand side of the Lewis                     structure is shown, which means it possesses a hydrogen bond.

◾ Ethane's structure:                                                         \(\\~~~~~~~H~~~~H\\~~~~~~~~|~~~~~|\\H-C-C-H\\~~~~~~~~|~~~~~|\\~~~~~~~H~~~~H\\\)

      → Does not have any hydrogens attached to the electronegative atoms listed above. Therefore, this does not possess a hydrogen bond.

◾ Dimethyl ether's structure:                                    \(\\~~~~~~~H~~~~~~~~~~H\\~~~~~~~~|~~~~~~~~~~~~|\\H-C-O-C-H\\~~~~~~~~|~~~~~~~~~~~~|\\~~~~~~~H~~~~~~~~~~H\\\)

      → Has the necessary electronegative atom, which is the oxygen, inside the structure. However, it does not obtain any bonding through hydrogens and instead attaches to the carbons, concluding that dimethyl ether does not contain any hydrogen bonding.

◾ Ethylene's structure:                                                                    \(H~~~~H\\~~|~~~~~|\\~C=C\\~~|~~~~~|\\~H~~~H\\\)
      → Clearly not possessing an electronegative atom bonding with a hydrogen, therefore, does not have any hydrogen bonding.  

In summary, the only organic compound that contains a hydrogen bond is ethanol.

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Teniendo en cuenta que la molaridad es el número de moles de soluto que están disueltos en un determinado volumen, la molaridad de la disolución de HNO₃ es 14.67 \(\frac{mol}{L}\).

El porcentaje en masa o en peso de una disolución es el número de gramos de soluto que hay por cada 100 gramos de disolución.

Entonces una pureza de 65% indica que hay 70 g de HNO₃ puro por cada 100 g de HNO₃ impuro.

Por otro lado, la densidad es la relación entre el peso o masa de una sustancia y el volumen que ocupa esa misma sustancia.

Entonces, si la disolución de HNO₃ tiene una densidad de 1.32 g/mL (equivalente a 1320 g/L), donde la cantidad de masa es impura, se puede obtener la cantidad de masa de HNO₃ presente 1 L de la solución mediante el siguiente cálculo:

\(\frac{1320 g HNO_{3} impuro}{1 L}x \frac{70 g HNO_{3}puro}{100 g HNO_{3}impuro}= 924 \frac{g HNO_{3}puro}{L}\)

Finalmente, la masa molar de HNO₃, es decir la masa presente en un mol de la sustancia, es 63 \(\frac{g}{mol}\).

Entonces, teniendo en cuenta que la molaridad es el número de moles de soluto que están disueltos en un determinado volumen, es posible determinar la molaridad como:

\(\frac{924 g HNO_{3}puro}{L}* \frac{1 mol}{63 g}= 14.67 \frac{mol}{L}\)

En resumen, la molaridad de la disolución es 14.67 \(\frac{mol}{L}\)

Aprende más sobre la molaridad:

Answer:

(1)N2+3F2 -> 2NF3

Explanation:

This problem can be done a few ways.

This reaction is a redox reaction, so it will be treated as such:

First, we count the number of N atoms there are on both sides
the left has 2 and the right has 1. The LCM of 2 and 1 is 2, so the lcm of nitrogen is 2.
Similarly, the lcm of fluorine is 6, since the lcm of 2 and 3 is 6.

The LCM is also the number of atoms that there are on both sides, so there are 2 nitrogens and 6 fluorines on both sides, which isn't hard to distribute.

Here's another example:
P4 + O2 -> P2O5
lcm of 4 and 2 is 4, so there are 4 Phosphoruses on both side
Lcm of 2 and 5 is 10, so there are 10 oxygen atoms on both side

Once we know the total amount of atoms on both side, distributing them isn't very hard

(P4+5O2-> 2P2O5)

Answer: Option A, 66.5

Explanation:

So you want to use the heat capacity formula

So, q(heat)=m(mass) * cp (specific heat) * DeltaT (change in temp)

so m=45.8, cp =0.385, q=1172

you dont have the final temp for DeltaT so you have to fill in and divide

1172 = (45.8) * (0.385) * Delta T

1172 = 17.633 * DeltaT (Now divide)

1172/17.633 = Delta T

66.46 = Delta T, rounded you get 66.5 or option A

Pbcl2 precipitate when 275 ml of a 0.134 m solution of pb(no3)2 is added to 125 ml of 0.0339 m solution of nacl? the ksp of pbcl2 is 1.17e-5.

Given that,

The volume of NaCl = 125 ml

Concentration of NaCl = 0.0339 m

The volume of Pb(NO3)2 = 275 ml

Concentration of Pb(NO3)2 = 0.134 m

K(eq) = 1.17 × 10(-5) --------(1)

Total volume = 275 + 125 = 400 ml

Pb(NO3)2 ------- Pb(+2) + 2 NO3(-)

at t = 0 0.134 0 0

at t = t 0 0.134 0.134

NaCl -------- Na(+) + Cl(+)

at t = 0 0. 0339 0 0

at t = t 0 0.0339 0.0339

PbCl2 ---------- Pb(+2) + 2Cl(-)

Q(sp) = [Pb+2] [ Cl-]^2

By substituting the values of conc. of all the ions, we get Pbcl2 precipitate when 275 ml of a 0.134 m solution of pb(no3)2 is added to 125 ml of 0.0339 m solution of nacl? the ksp of pbcl2 is 1.17e-5.

= (275 × 0.134/ 400) (125 × 0.0339/400)^2

= 9.8 × 10(-6)

As we noticed that, Ksp > Qsp

Therefore, PbCl2 will not precipitate.

Thus, we concluded that the Pbcl2 precipitate when 275 ml of a 0.134 m solution of pb(no3)2 is added to 125 ml of 0.0339 m solution of nacl? the ksp of pbcl2 is 1.17e-5.

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The angle of repose refers to the maximum angle at which a granular material, such as sand, can remain stable without sliding or flowing. It is the angle between the horizontal surface and the slope formed by the material's natural pile or cone shape.

When sand-sized particles fall from the air and accumulate, they tend to form a cone-shaped pile due to gravity and the interlocking and friction between the particles. As more particles are added to the pile, the slope of the pile increases until it reaches a point where the gravitational forces acting on the particles are balanced by the friction and interlocking forces between them. This point is the angle of repose.

The angle of repose depends on various factors, including the particle size, shape, and density. Smaller particles with smoother surfaces may have a lower angle of repose compared to larger particles with rougher surfaces. Similarly, denser particles may form steeper piles compared to less dense particles.

It's important to note that the angle of repose is an approximation and can vary based on conditions such as moisture content, compaction, and other environmental factors. Additionally, particles falling from the air may not always reach their angle of repose immediately, as they may undergo additional settling and reorganization over time.

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If the atom in Drawing B had been removed by physical separation from one of the substances in Model 1, the substance that could have been the source of the atom in Drawing B is an element.

An atom is the smallest part of a substance that can take part in a chemical reaction. We know that elements are composed of atoms. The atoms of an element are discretely arranged. Thus, in an element, there are so many atoms of the substance.

In the image that has been shown in the question, the source of the atom as it has been show is an element. Thus, if the atom in Drawing B had been removed by physical separation from one of the substances in Model 1, the substance that could have been the source of the atom in Drawing B is an element.

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The formation of solid magnesium chloride (MgCl₂) by the reaction between chlorine gas (Cl₂) and magnesium metal (Mg) at high temperatures is classified as a synthesis reaction or a combination reaction.

Synthesis reactions involve the combination of two or more substances to form a single product. In this case, chlorine gas and magnesium metal combine to produce magnesium chloride as the sole product.

The balanced chemical equation for this synthesis reaction is:

Mg + Cl₂ ⇒ MgCl₂

Hence, the reaction between chlorine gas and magnesium metal to form solid magnesium chloride indicates a synthesis reaction, as the elements combine to form a compound.

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Cu₂+ and Ni₂+ are expected to form low-spin complexes, while Co₂+ is not.

Negatively charged subatοmic particles called electrοns can be free—that is, nοt bοund—οr bοnded tο an atοm. There are three main types οf particles in an atοm: prοtοns, neutrοns, and an electrοn that is bοnded tο an atοm. The nucleus οf an atοm is cοmpοsed οf prοtοns and electrοns.

According to the statement provided, metal ions with d8 or more electrons will always be low-spin, regardless of the identity of the attached ligands. Based on this information, we can determine which of the ions would be expected to form low-spin complexes:

Cu₂+ (d9): Since Cu₂ + has 9 d-electrons, it falls within the range of d8 or more electrons. Therefore, Cu₂ + is expected to form low-spin complexes.

Ni₂ + (d8): Ni₂ + also has 8 d-electrons, which falls within the range mentioned. Therefore, Ni₂ + is also expected to form low-spin complexes.

Co₂ + (d7): Co₂ + has 7 d-electrons, which is less than the required d8 or more electrons for low-spin complexes. Hence, Co₂ + is not expected to form low-spin complexes.

In summary, Cu₂ + and Ni₂ + are expected to form low-spin complexes, while Co₂ + is not.

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The likely source of the phosphate on galactose-1-phosphate is ATP (adenosine triphosphate), which is an energy currency of the cell and used for phosphorylation reactions in metabolic pathways.

In metabolic pathways, ATP transfers its energy to other molecules through phosphorylation reactions, where a phosphate group is transferred from ATP to another molecule. In the case of galactose metabolism, galactose is first converted to galactose-1-phosphate by the enzyme galactokinase, which uses ATP as the source of the phosphate group. The resulting galactose-1-phosphate is then converted into glucose-6-phosphate through a series of enzymatic reactions.

Therefore, the phosphate group on galactose-1-phosphate is most likely derived from ATP, which is an important energy source in metabolic pathways and is used for phosphorylation reactions to activate or convert other molecules.

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Answer:

A bias occurs in an experiment when a scientist expects something to happen and lets this influence how the results are viewed. Scientists try to reduce bias whenever they can by doing the experiment many times and keeping careful notes about observations.

Explanation:

a. Gases have particles that move rapidly in all directions, frequently colliding with each other and the side of the container  resulting in no definite shape or volume.

b. Liquids  have particles can move around one another resulting in the particles being strong enough to hold a specific volume.

c. Solids have particles vibrate around fixed positions resulting in the particles vibrate faster and faster until they have enough energy to break away from their fixed positions.

A particle is described as a small localized object which can be described by several physical or chemical properties, such as volume, density, or mass.

In conclusion, the particles in solids are very close together, therefore they cannot usually be compressed or squashed.

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It is very important to know how elements and compounds react together because everything that surrounds us is made out of elements and compounds. Therefore, understanding how these work can allow us to have a better understanding of the world that surrounds us. Moreover, it can avoid accidents when we deal with dangerous compounds, such as when we cook or clean.

Some elements are more "reactive" than other elements because the number of electrons in the outermost shell of the atom is greater that that of others.

A chemical element is a species of atoms that have a given number of protons in their nuclei, including the pure substance consisting only of that species.

The known elements have certain properties that helps in their identification .Those properties include  but are not limited to the following:

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Answer:

it is very important to know how elements and compounds react together because everything that surrounds us is made out of elements and compounds. Therefore, understanding how these work can allow us to have a better understanding of the world that surrounds us. Moreover, it can avoid accidents when we deal with dangerous compounds, such as when we cook or clean.

Explanation:

Answer: Why exacly am i a rat

Explanation:

,....

but thanks

Answer:

what!!!??????

Answer:

5.0 moles

Explanation:

213/390 x 9.22 = 5.04

Round to least sig fig (390 ml)

5.0