Please help. 100 points

She changed the mask chemically. Burning of the substance with acid is a chemical change.

A new substance with new qualities is created during burning, which is a chemical alteration that cannot be undone. A chemical change is the transformation of one substance into another, the emergence of new compounds with distinct properties, or any combination of these. It happens when two substances mix to create a new material. Baking soda and vinegar producing carbon dioxide, iron rusting, and wood burning are a few examples of chemical changes. The metabolization of food and the production of amylase from the combining of sugar and saliva are only two examples of the many chemical processes that the body produces.

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Answer: D

Explanation:

electrons have no mass

Measuring tools like Clear ruler, yardstick, measuring tape etc. They are very useful for the perfect fit and shape of any garment and even home furnishing.  

Sewing is the craft of fastening or attaching objects using stitches which is made up of a sewing needle and thread.

Measuring tools are the instruments used by practitioners and researches to aid in the assessment or evaluation of the subjects, clients or patients etc. These instruments are used to measure or collect the data on a variety of variables ranging from psychosocial wellbeing or physical functioning.

Measuring tools in sewing are as follows: Measuring tape, clear ruler, quilting ruler, yardstick, French curve etc.

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The amount of matter contained within an object is commonly referred to as mass. The most typical way to measure it is as inertial mass, which refers to an object's resistance to acceleration under the influence of a net force. 

Although the size of an object and its mass are frequently associated, larger objects do not always have more mass. For instance, an inflated balloon would have substantially less mass than a silver golf ball. Although there are numerous alternative units used to describe mass around the world, the kilogram is the accepted unit of mass according to the International System of Units (SI) (kg).

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The price of the wax from the U.S. supplier in €/kg would be: €25.53 / 2.20 lb = €11.67/kg.

The price of the wax from the German supplier in $/lb would be $11.90 / 0.76 = $15.68/lb.

This price is calculated by taking the cost of the wax in US dollars and converting it to Euros using the current exchange rate of $1 = €0.76.

This price is calculated by taking the cost of the wax in Euros and converting it to US dollars using the current exchange rate of $1 = €0.76. It's important to note that the price of the wax from the German supplier is higher than the price from the US supplier when converted to dollars per pound.

This is because the price per kg is lower but the conversion to pound makes it higher.

The price of the wax from the U.S. supplier in €/kg would be: €25.53 / 2.20 lb = €11.67/kg.

The price of the wax from the German supplier in $/lb would be $11.90 / 0.76 = $15.68/lb.

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The statement is False, when lead-209 undergoes beta decay. As the nuclear equation is n ---> p + e- + antineutrino.

Lead-209 is an atom that contains 82 protons and 127 neutrons in its nucleus, meaning that lead-209 is not a neutron. Neutrons are particles that are found in the nucleus of atoms and have no charge. Therefore, lead-209 can't undergo beta decay by emitting a neutron. Beta decay occurs when an unstable nucleus emits a beta particle and an antineutrino, changing the number of protons in the nucleus. The balanced nuclear equation for the beta decay of lead-209 would be Pb-209 (atomic number = 82) --> Bi-209 (atomic number = 83) + e- + antineutrino. The Bi-209 is a isotope of bismuth, which has one more proton than lead-209 and the same number of neutrons.

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Question-- Select True or False: When lead-209 undergoes beta decay the balanced nuclear equation for this reaction is: n ---> p + e- + antineutrino

Elements 'X', 'Y' and 'Z' have these atomic radii, in nanometers. X 0.072 nm Y 0.099 nm Z 0.111 nm. When atomic radii are correctly arranged,  the elements appears as z , y and then x across the period.

The atomic radii decreases across the period as we move from the left to right in the periodic table. the atomic radii will decreases as we move from the left to the right in the periodic table because in the period from the left to right the number of the electron will increases.

Thus, the order of the given elements arranged in the period in the periodic table as first z , then y and then x.

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The formula for the equilibrium constant is; [tex][HI]^{2} /[H_{2} ] [I_{2} ][/tex]

We know that when we talk about the equilibrium constant that we are looking at the kind of constant that shows the extent to which there has been the conversion of the reactants to the products.

We can be able to obtain the equilibrium constant of the system by the application of the law of mass action and this would give the correct6 form of the expression for the equilibrium constant. This is how we know which of the species would have the square.

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Mass is a measure of an object's resistance to acceleration.

1. Calculate the total mass of the sample:

37.50 g

2. Calculate the total mass of the elements O and C:

19.01 g + 4.76 g = 23.77 g

3. Calculate the mass of Cr:

37.50 g - 23.77 g = 13.73 g

4. Calculate the composition of Cr in the compound:

13.73 g / 37.50 g x 100 = 36.56

What is Mass?

The resistance to acceleration of an object is measured by its mass. It is a fundamental property of physical objects and is often expressed in kilograms (kg) or grams (g). Mass is related to the inertia of an object, which is a measure of how difficult it is to change the object's motion. Mass also determines the strength of the gravitational force acting on an object.

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The final pressure if the final volume is 1. 22 L will be 0.4234 atm

To calculate the final pressure of the hydrogen in the balloon if the final volume is 1.22 L, the ideal gas law can be used. The ideal gas law states that PV = NRT, where P is the pressure, V is the volume, n is the number of moles of gas, R is the ideal gas constant, and T is the temperature.

Since the number of moles and the temperature is not given, we can assume that they remain constant. So we can use the equation PV = k, where k is a constant.

Given the initial pressure and volume of the hydrogen are 0.95 atm and 0.55 L respectively.

0.95*0.55 = k

so k = 0.5175

then the final pressure can be calculated by:

P1V1 = P2V2

0.950.55 = P21.22

P2 = (0.5175) / (1.22) = 0.4234 atm

The final pressure of the hydrogen in the balloon will be 0.4234 atm.

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The balanced chemical equation is N₂ + 3 H₂[tex]\rightarrow[/tex] 2 NH₃ which gives the formation of ammonia.

Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.

The first chemical equation was put forth by Jean Beguin in 1615.By making use of chemical equations the direction of reaction ,state of reactants and products can be stated. In the chemical equations even the temperature to be maintained and catalyst can be mentioned.

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Cribbing is the tool we use prior to making your first extrication cut in the vehicle

Before making the first extrication cut, it is important to stabilize the vehicle to prevent it from moving and to ensure the safety of the individuals involved in the extrication process. One tool that is commonly used to stabilize a vehicle during extrication is a set of stabilizing struts, also known as cribbing. Cribbing is a set of wooden or composite blocks that are placed under the vehicle to support it and prevent it from moving. The cribbing is typically placed at strategic points, such as the frame of the vehicle or the wheels, to provide a stable base for the vehicle.Additionally, other tools like wheel chocks, jacks, and air bags may be used to provide additional support and stability. The extrication team will assess the situation and choose the most appropriate tool to stabilize the vehicle.

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Calcium oxide reacts with water to form calcium hydroxide which is a type of combination reaction. Therefore, the balanced chemical equation is: CaO+H2O→Ca(OH)2+Δ

The symbolic representation of a chemical reaction is a chemical equation. In this, the formulas and symbols for the reactants and products are used to depict them. Since the Middle Ages, quicklime, also known as calcium oxide, has been utilized as an alkaline substance. One of the oldest substances that humans have ever discovered is quicklime. Other names for it include lime or burned lime. Lime, or calcium oxide, is a chemical substance with the formula CaO. When calcium oxide, also referred to as quick lime, and water combine, calcium hydroxide is created (commonly known as slaked lime). This reaction is an example of a combination reaction.

Calcium oxide + Water → Calcium hydroxide

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The occurrence of elements properties in which it repeats every after the eight elements named a periodicity.

Periodicity would be the reappearance of identical features in an element's behavior when it is organized in atomic number-increasing at frequent intervals.

The repeating of a comparable electronic configuration of an element's atoms in its outermost electron shell after such a predetermined regular interval that's what causes periodicity in its properties.

The elements were organized by chemist John A. R. Newland in order of increasing their atomic weight. He gave it the name "the principle of Octaves" and described how a particular collection of qualities recurs every eight places.

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A chemist reported that 100 gallons of a gas were available in a laboratory, The property of the gas did the chemist report is volume option - D is correct answer.

The space occupied by a three-dimensional object is measured using the scalar quantity known as volume. The volume of a liquid or gas is calculated using the container's capacity as the unit of measurement.

A state of matter known as gas lacks a consistent shape and a set volume. They are the least dense and have the most space between their moles.

A gallon is a unit of volume that is used in the American metric system. The volume of gas equals the sum of the moles of gas in the container, which contains 100 gallons of gas.

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His and Lys are deprotonated but Asp will be protonated.

Organic substances that possess both amino and carboxylic acid functional groups are known as amino acids. Although hundreds of amino acids occur in nature, the alpha-amino acids that constitute proteins are by far the most significant. The genetic coding contains only 22 alpha amino acids. Amino acids are chemicals that make proteins when they combine. The building blocks of life are amino acids and proteins. Amino acids are left over after proteins are digested or broken down. To support the body, the human body utilizes amino acids to build proteins: Food should be broken down.

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As the pH is given as 7.4 and pK of His is given as 6.00. There will occur a positive charge on His when it's pH < pK therefore, it is neutral at the given pH.

As the pK value of Lys is 10.53 that is greater than the pH of 7.40. Therefore, charge on Lys is positive.

As the pK value of Asp is 3.65 which is less than the pH value of 7.40. Hence, Asp has a negative charge.

Therefore, we can conclude that His and Lys are deprotonated but Asp will be protonated.

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a. Acetylacetone(acacH) can form up to 4 bonds with a metal ion.

b. Dirthylenetriamine can form up to 4 bonds with a metal ion.

c. Salen can form up to 6 bonds with a metal ion.

d. Porphine can form up to 8 bonds with a metal ion.

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To solve this we must be knowing each and every concept related to   ideal gas equation. Therefore, the pressure when the volume is doubled is  3atm.

Ideal gas equation is the mathematical expression that relates pressure volume and temperature.

Mathematically the relation between Pressure, volume and temperature can be given as

PV=nRT

where,

P = pressure of gas

V= volume of gas

n =number of moles of gas

T =temperature of gas

R = Gas constant = 0.0821 L.atm/K.mol

rearranging the above equation, we get

P₁V₁= P₂V₂

{ (6atm) (10dm[tex]_3[/tex])}  ={ ( P₂) (20dm[tex]_3[/tex])}

P₂ = 3atm

Therefore, the pressure when the volume is doubled is  3atm.

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The diagrams of the arrangement of the electrons in calcium and magnesium have been shown in the image attached to this answer. There are two electrons in the valence shell of calcium.

We know that the electrons are the subatomic particles that we can be able to see in the shells of the atom. It is important that we ought to know that the electrons are the particles that are known to be responsible for the reactivity of the atom.

The number of the electrons that we can find in the atom would depend on the number of the protons that we have in the nucleus of the atom and this is because for the atom to be electrically neutral then we would have to have the same number of electrons and protons being in the atom as we know.

It is clear that calcium is a member of group two of the periodic table and that magnesium is also a member of group two of the periodic table.

The structures for calcium would have Ca and two dots while that of magnesium would have Mg and two dots.

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Answer:

A climograph is a graphical representation of the climate of a particular location over a period of time. It typically shows the average temperature and precipitation for a specific location over the course of a year, with the temperature plotted on the y-axis and the months of the year plotted on the x-axis.

The primary function of a climograph is to provide a visual representation of the climate of a particular location, which can be useful for understanding the weather patterns and temperature ranges that are typical for that location. Climographs can also be useful for comparing the climate of different locations, as they provide a convenient way to see how temperature and precipitation patterns differ from one place to another.

Sodium chloride reacts with silver nitrate.  NaCl + AgNO3 → AgCl + NaNO3

intermolecular forces present in it.

The attracting and repellent forces that develop between the molecules of a substance are known as intermolecular forces or IMF for short. Individual molecules of a substance interact with one another through the mediation of these forces.

Most of the physical and chemical features of matter are caused by intermolecular forces.

An intermolecular force is an attractive force that develops between the protons or positive parts of one molecule and the electrons or negative parts of another molecule. This force affects a substance's many physical and chemical properties. The strength of a material's intermolecular forces directly relates to the boiling point of that substance; the stronger the intermolecular forces, the higher the boiling point.

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The rate constant at 65 C is k65= 4.8 x 10^-5 s^-1 .Below is the explanation for the answer

To find the rate constant at a different temperature, you can use the Arrhenius equation, which relates the rate constant to the activation energy and the temperature. The equation is:

k = A * e^(-Ea/RT)

where
k is the rate constant,
A is the pre-exponential factor (also known as the frequency factor),
Ea is the activation energy,
R is the universal gas constant,
T is the absolute temperature.

We are given that the activation energy is 83.5 kJ/mol and the rate constant at 45 C is 3.54 x 10^-5 s^-1. To find the rate constant at 65 C, we can substitute these values into the equation and solve for k.

k = A * e^(-Ea/RT)
k = 3.54 x 10^-5 s^-1 * e^(-(83.5 kJ/mol) / (8.314 J/mol*K * (45 + 273.15 K))

However, A is a constant that we don't know. To find the rate constant at 65 C, we can use the fact that the rate constant is proportional to the temperature. Therefore, we can find the ratio of the rate constants at 65 C and 45 C, then multiply it by the rate constant at 45 C to find the rate constant at 65 C.

k65/k45 = (T2/T1)^n
where
k65 is the rate constant at 65 C
k45 is the rate constant at 45 C
T2 is the temperature in Kelvin (65 + 273.15)
T1 is the temperature in Kelvin (45 + 273.15)
n is the order of the reaction, which is 1 in this case

we can find the rate constant at 65 C is:
k65 = k45 (T2/T1)^n
k65 = 3.54 x 10^-5 s^-1 * ( (65 + 273.15) / (45 + 273.15) )^1

k65= 4.8 x 10^-5 s^-1

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Radioactive dating measures the rate of decay of radioactive materials in rocks.

Radiometric dating, radioactive dating, or radioisotope dating is a technique used to date things such as rocks or carbon that included trace radioactive contaminants when they were produced. Radioactive dating is a technique for dating rocks and minerals that makes use of radioactive isotopes. This approach is appropriate for igneous and metamorphic rocks that cannot be dated using the sedimentary stratigraphic correlation method. There are around 300 naturally occuring isotopes known. The underlying idea behind radiometric dating is that you can compute the age of a sample by comparing the presence of a radioactive isotope within it to its known abundance on Earth and its known half-life (rate of decay).

Here,

Radioactive dating determines the rate at which radioactive elements in rocks decay.

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(A) Vol. of solvent is 119.8 ml, (B) Molarity (M) of sol. is 5.00 M, (C) V1 of copper nitrate solution is 187.5 ml, (D) The instruction given is false.  

(A). To calculate the volume (ml) of a 2.25 M potassium hydroxide solution that contains 15.0 g of solute, we can use the formula:

The unit of measurement for molarity (M) is moles of solute per liter of solvent.

Rearranging the formula to solve for liters of solvent:

Molecularity = moles of solute / liters of solvent (M)

We know that the molar mass of potassium hydroxide (KOH) is 56.1 g/mol. To find the moles of solute, we can divide the given mass (15.0 g) by the molar mass of KOH:

15.0 g / 56.1 g/mol = 0.2679 moles

Now we can plug this value into the formula above:

Liters of solvent = 0.2679 moles / 2.25 M

Liters of solvent = 0.1198 L or 119.8 ml (rounded to 3 significant figures)

(B). To calculate the molarity of a solution containing 1.25 moles of glucose in 250. ml of solvent, we can use the formula:

The unit of measurement for molarity (M) is moles of solute per liter of solvent.

Plugging in the given values:

Molarity (M) = 1.25 moles / 0.250 L

Molarity (M) = 5.00 M

(C). To calculate the volume of a 10.00 M copper(II) nitrate solution that must be added to water to prepare 750.0 ml of a 2.500 M solution, we can use the formula:

M1V1 = M2V2

Where M1 and V1 are the concentration and volume of the original solution, and M2 and V2 are the concentration and volume of the final solution.

We know that the final solution has a volume of 750.0 ml and a concentration of 2.500 M, so we can plug in these values for V2 and M2:

M1V1 = 2.500 M x 750.0 ml

Now we can solve for V1 (the original volume) by rearranging the formula:

V1 = M2V2 / M1

V1 = (2.500 M x 750.0 ml) / 10.00 M

V1 = 187.5 ml (rounded to 4 significant figures)

(D). The instructions "Take 100.0 mL of the 10.0 M solution and add 900.0 mL water" are not correct for diluting a 10.0 M solution to a 1.00 M solution.

To achieve this dilution, you would need to take a smaller volume of the 10.0 M solution and add a larger volume of water, because the final volume should be larger than the starting volume.

For example, you could take 10.0 mL of the 10.0 M solution and add 90.0 mL of water, which would give you a final volume of 100.0 mL and a concentration of 1.00 M. The instruction given above is false.

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In a car engine, energy in the fuel's chemical energy stores is transferred to useful kinetic energy stores.

Explanation:

Chemical energy is the form of energy held within the fuel. A car's engine operates by burning fuel. The fuel is burned, creating mechanical energy that moves the vehicle. The engine thus transforms chemical energy into mechanical energy.

By applying pressure to the pistons and exerting work on them, the internal combustion engine of a car transforms the potential chemical energy in gasoline and oxygen into thermal energy, which is then translated into mechanical energy that drives the vehicle (raising its kinetic energy).

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Answer:

Amoeba has no special respiratory organs and no respiratory pigments but there is a free exchange of gases by diffusion through the general body surface which is permeable to the gases dissolved in water

Part-1 The instantaneous rate at 0.000s is 1.8 ×10⁻⁷m/s.

Part-2 The instantaneous rate at 0.0s is 5.3×10⁻⁸m/s.

The concentration change over a chosen time period is the average rate. When you take the measurements makes a difference. The instantaneous rate is the rate that exists at a specific time. The solution is found at that point by determining the slope of the tangent to the concentration vs. time curve.

Given chemical reaction,
SO₃(g) + NO(g) --------> NO₂​(g) + O₂​(g)

t =  0. 000s

instantaneous rate = 1.38×10⁻⁸ - 2.0×10⁻⁸/0.011 - 0.000

instantaneous rate = 1.8 ×10⁻⁷m/s

Therefore the instantaneous rate at 0.000s is 1.8 ×10⁻⁷m/s.

for t = 0.052s,

instantaneous rate = 1.2×10⁻⁸ - 1.6×10⁻⁸/0.102 - 0.027

instantaneous rate = 5.3×10⁻⁸m/s.

Therefore the instantaneous rate at 0.0s is 5.3×10⁻⁸m/s.

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