Please help infer a quantitative measurement that can be made from the scene shown. be sure to use at least one complete content related sentence.

Explanation:Once the crime scene has been thoroughly documented and the locations of the evidence noted, then the collection process can begin

Answer: d.The medical examiner should oversee the collection of the evidence at the crime scene.

Explanation:

The physical evidence includes all the evidences which shows the proximity of victim or culprit with the crime scene. The medical examiner should help in collection of the evidences at the scene of crime. The medical examiner can search and identify physical evidences such as blood, sweat, vomit, fecal matter, urine, bodily tissues as an evidence and can begin the process of collection without contamination.

To determine the maximum mass of sucrose that can be added to 1.50 kg of pure water and still have the solution freeze at -15.0 °C, you can use the molality and freezing point depression equations.

To determine the maximum mass of sucrose you can add to 1.50 kg of pure water and still have the solution freeze at -15.0 °C, we need to calculate the molality of the solution and use the colligative property of freezing point depression.

The molality is the moles of solute per kilogram of solvent. Since sucrose does not ionize, it remains as molecules in the solution. We can use the equation:

m = moles of sucrose / mass of water (kg)

With the molality, we can use the freezing point depression equation to determine the change in freezing point:

ΔTf = Kf * m

The freezing point of pure water is 0.0 °C, so the new freezing point will be -15.0 °C. We can then solve for the moles of sucrose and convert it to mass using the molar mass of sucrose. The maximum mass of sucrose that can be added to the water without it freezing will be the calculated mass of sucrose.

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Answer:

B

Explanation:

5 kg = 5 kg * 1000 grams / kg = 5000 grams

10 cm does not require any conversion.

50 mm = 50 mm * 1 cm/10 mm = 5 cm

0.2 m = 0.2 m * 100 cm / 1 m = 20 cm

V = 10 cm * 5 cm * 20 cm

V = 1000 cm^3

Density = 5000 grams / 1000 cm^3 = 5 grams / cm^3

B

Answer: Part A:  Physical change: Status changes of matter

chemical change: Any Chemical reaction

Part B: Physical property: Color, odor, etc

Chemical property: Flammability

Explanation:

Part A:  A physical change: It´s change of form but not chemical composition.

Examples of Physical change are the Status changes of matter like boiling, melting, chooping wood, breaking a bottle  and shredding paper.

A chemical change:  It´s a change in the chemical composition of the compounds and generate new ones. That is called "chemical reaction" and it implies a rearrange of atoms generating new compounds.

Examples of chemical change are oxidation of Iron, burning, cooking, digesting food, rusting of iron.

Part B: Physical property: Are properties that can be measured or observed directly with our senses

Examples of physical Property:  density,, appearance, texture, polarity, color, odor, melting point, solubility.

Chemical property:  Are properties that can be observed when tey participate in a chemical reaction.

Examples of chemical Property: Reactivity , Radioactivity, Flammability , Acidity or basicity

Final answer:

A physical property of a substance can be observed without changing its chemical identity, such as melting point, while a chemical property, like flammability, involves a substance's propensity to change chemically. Physical changes do not alter a substance's chemical identity, unlike chemical changes which result in the formation of new substances.

Explanation:

Physical and Chemical Changes

Chemists categorize the properties of matter into physical and chemical properties. A physical property is an aspect of matter that can be observed or measured without altering the substance's chemical identity. Examples include color, density, melting and boiling points.

In contrast, a chemical property describes the substance's ability to undergo a specific chemical change, which alters its chemical composition. Flammability is a chemical property because it describes a substance's ability to burn, changing it into different substances as a result of this process.

Classifying Properties and Changes

Part A: One might observe a physical change when ice melts into water or when water vapor condenses - these are changes in state that do not involve altering the chemical identity of the substance. Chemical changes, however, such as the rusting of iron or the burning of wood, result in the formation of new substances.

Part B: Reflecting on the information given, properties like size, shape, and mass are physical, as they can be measured or observed without changing the material's chemical composition. In contrast, properties like reactivity with acids or the ability to oxidize would be classified as chemical properties, as they imply a change in chemical composition.

Answer:

The answer to your question is below

Explanation:

The atom in a chemical bond that attracts electrons more strongly acquires a(n)__negative______ charge, and the other atom acquires a(n)_positive_______ charge. If the electron transfer is significant but not enough to form ions, the atoms acquire _dipoles_________ and charges. The bond in this situation is called a polar covalent bond.

Elements with full outer shells of electrons are more stable. Atoms tend to donate, accept, or share electrons to fill their outermost shells, following the octet rule.

Elements with atoms that have full outer shells of electrons are more stable compared to those with incomplete outer shells. The octet rule states that atoms tend to donate, accept, or share electrons with other elements to fill their outermost shells and satisfy the octet rule.

Oxygen is an example of an element that reacts with other elements to achieve an octet configuration. Thus, elements with complete outer electron shells are more stable because they have low reactivity and are less likely to form chemical bonds. This stability is a fundamental principle in the periodic table, guiding chemical behavior.

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Answer:

C₅H₁₂

Explanation:

To obtain the answer for this question we need to do a combustion analysis. When a hydrocarbon is heated, it means that it reacts with oxygen (O₂) to produce two known products which are carbon dioxide (CO₂) and water (H₂O), and by knowing the masses of these products, we can know the proportions of the elements that initially were part of the hydrocarbon, in this case, the C/H ratio.

First, we propose the next reaction, assuming that all the hydrocarbon sample was combusted:

CxHy(s) + O₂(g) → xCO₂(g) + yH₂O(g)

Now, with the provided masses of the carbon dioxide and the water, we can calculate the molar amounts of carbon and hydrogen in the sample.

First we calculate the molar masses:

C = 12.011 x 1 = 12.011 g/mol

O = 15.99 x 2 = 31.99 g/mol

CO₂ = 12.011 + 31.99 = 44.001 g/mol

H = 1.008 x 2 = 2.016 g/mol

O = 15.99 x 1 = 15.99 g/mol

H₂O = 2.01 + 15.99 = 18.006 g/mol

Now we obtain the molar amounts of C and H using the obtaines masses of carbon dioxide and water:

mol C = 30.50g CO₂ x (1mol CO₂)/(44.001 g/mol)  x (1mol C)/(1mol CO₂) = 0.6931 mol C

mol H = 14.98g H₂O x (1mol H₂O)/(18.006 g/mol)  x (2mol H)/(1mol H₂O) = 1.6638 mol H

Finally, we can obtain the H/C molar ratio by identifying the smaller whole-number ratio for these molar amounts. For this we can first divide each molar amount by the smaller amount:

mol C = 0.6931/0.6931 = 1

mol H = 1.6638/0.6931 = 2.4

As we are still getting a decimal amount for the hydrogen, what we can do is multiply both molar amounts by the smaller whole multiple that can give us a whole number for the hydrogen's molar amount, in this case, that multiple would be 5:

mol C = 0.6931/0.6931 = 1 x 5 = 5

mol H = 1.6638/0.6931 = 2.4 x 5 = 12

Now we can write the empirical formula for the hydrocarbon, which is:

C₅H₁₂

Final answer:

To determine the empirical formula of the hydrocarbon, we need to calculate the moles of carbon and hydrogen in the sample. Once we have the moles of carbon and hydrogen, we can determine the empirical formula by finding the simplest whole number ratio between the two elements.

Explanation:

To determine the empirical formula of the hydrocarbon, we need to calculate the molar amounts of carbon and hydrogen in the sample. From the given masses of carbon dioxide (30.50 g) and water (14.98 g), we can determine the moles of carbon and hydrogen in the sample. The molar ratios of carbon and hydrogen in the compound will give us the empirical formula.

First, let's calculate the moles of carbon and hydrogen:

Moles of carbon = mass of carbon dioxide / molar mass of carbon dioxide

Moles of hydrogen = mass of water / molar mass of water

Once we have the moles of carbon and hydrogen, we can determine the empirical formula by finding the simplest whole number ratio between the two elements.

For example, if we find that the moles of carbon is twice the moles of hydrogen, the empirical formula would be CH2.

The solution with the highest number of particles in solution (CaCl2 in this case), experiences the highest osmotic pressure, lowest vapor pressure and highest boiling point due to the principles of colligative properties.

The question pertains to the colligative properties of solutions, which would be governed by the number of particles in the solution. The solutions are 0.04 m urea [(NH2)2C=O)], 0.04 m AgNO3, and 0.04 m CaCl2. For (i) Highest osmotic pressure, the solution with the highest ion count would yield the highest osmotic pressure. CaCl2 dissociates into three ions (Ca²+, and 2 Cl¯), therefore, it would exhibit the highest osmotic pressure. For (ii) Lowest vapor pressure, this would coincide with the solution with the highest osmotic pressure, again making it CaCl2, due to the greatest decrease in vapor pressure. For (iii) the highest boiling point, this too would be CaCl2 for the reasons stated above. The presence of more particles in a solution interferes more with the evaporation process, requiring more energy (higher temperature) to achieve boiling.

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Answer:

The mass chloride is 2.903 grams

Explanation:

Step1: calculate the moles of FeCl3

moles = molarity  x  volume  in liters

volume in liters = 100 ml /1000 =  0.1 L

molarity = 0.273  M  =  0.273  mol / L

moles   =   0.273  mol /L  x 0.1 L = 0.0273   moles

step 2:  find the moles of Cl

since there is  3  atoms of  cl in FeCl3

= 3 x 0.0273 =0.0819 moles

Step 3:  calculate  mass  of cl

 mass= moles  x molar mass

=0.0819 moles x 35.45 g/mol = 2.903 g

The mass of chloride in grams is 2.903 grams.

Mass is defined as the quantitative measure of inertia, a fundamental properties of all the matter.

It can also be defined as the amount of matter present in any object or matter.

First calculate moles of FeCl3

Moles = Molarity x Volume in liter

Molarity = 0.273 mole / liter

Volume = 100ml = 0.1 l

Moles = 0.273 x 0.1 = 0.0273 moles

For FeCl3 3 molecules of Cl is needed

So, Moles of Cl = 3 x 0.0273

                         = 0.0819 moles

Now calculate the mass of Cl

Mass = moles x molar mass

         = 0.0819 x 35.45

         = 2.903 grams

Thus, the mass of chloride in grams is 2.903 grams.

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Answer:

Poly(ethenol), ie poly(vinyl liquor), PVA, has a rehashing vinyl liquor unit with a sub-atomic equation of [-CH2 CHOH-]n. Its atomic weight can go from 25000 to 300000, contingent upon its chain length, which influences its consistency.  

Borax, ie sodium tetraborate decahydrate, Na2B4O7.10H2O, when broken down in water, hydrolyses to frame a boric corrosive borate particle arrangement with a pH of around nine.  

B4O72–(aq) + H2O(l) → HB4O7–(aq) + OH–(aq)  

B4O72–(aq) + 5H2O(l) + 2H+ (aq) → 4H3BO3 (aq)  

B(OH)3 (aq) + H2O(l) → B(OH)4–(aq) + H+ (aq)  

Explanation:

Borax is intriguing since it contains boron molecules with both tetrahedral and trigonal planar stereo chemistry. Boric corrosive's acridity is clarified by electron pair acknowledgment as opposed to proton gift, and it is in this manner a monoprotic corrosive, not triprotic true to form.  

At the point when arrangements of poly(ethanol) and sodium tetraborate are blended, the borate particles, B(OH)4–(aq) respond with the hydroxyl gatherings (OH) of the poly(ethenol). Frail cross-connecting inside the polymer strikes produce a viscoelastic gel. The high dissolvability in water proposes that broad hydrogen holding exists.

Answer:

B.

Explanation:

It is brittle like a nonmetal but conducts electricity and heat  like a metal.

Answer: The correct answer is Option B.

Explanation:

Metalloids are defined as the elements which show properties of both metals and non-metals. There are 7 metalloids in the periodic table. They are Boron, Silicon, Germanium, Arsenic, Antimony, Tellurium and Polonium

Properties shown by metalloids:

Arsenic is a metalloid which belongs to Group 15 and Period 4 of the periodic table.

This element is brittle in nature and thus is similar to non-metals. Also, it conducts electricity and heat and thus is similar to metals.

Hence, the correct answer is Option B.

The mass (in mg) of 1.6×10¹⁷ molecules of sucrose, C₁₂H₂₂O₁₁ is 9.09×10¯² mg

From Avogadro's hypothesis,

Thus,

6.02×10²³ molecules = 1 mole of C₁₂H₂₂O₁₁

1 mole of C₁₂H₂₂O₁₁ = (12×12) + (1×22) + (16×11)

= 144 + 22 + 176

= 342 g

Next, we shall convert 342 g to mg. This can be obtained as follow

1 g = 1000 mg

Therefore,

342 g = 342 × 1000

6.02×10²³ molecules = 342000 mg of C₁₂H₂₂O₁₁

Therefore,

1.6×10¹⁷ molecules =  [tex]\frac{1.6X10^{17} X342000}{6.02X10^{23} }[/tex]

Therefore, the mass (in mg) of 1.6×10¹⁷ molecules of sucrose, C₁₂H₂₂O₁₁ is 9.09×10¯² mg

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To find the mass of a sugar crystal, we calculate the mass of a single sucrose molecule and then multiply it by the total number of molecules in the crystal. The result is that the sugar crystal has a mass of approximately 9.101 milligrams.

To calculate the mass of a sugar crystal in milligrams (mg), we need to find the mass of one sucrose molecule and then multiply it by the total number of sucrose molecules present. The molar mass of sucrose (C12H22O11) is 342.30 grams per mole (g/mol), which we can use to find the mass of one molecule.

First, we convert the molar mass to milligrams per molecule:

 342.30 g/mol × (1 mol / 6.022×1023 molecules) × (106 mg / 1 g) = 5.688×10-19 mg/molecule
Then, we multiply the mass of one molecule by the number of molecules in the sugar crystal:

 5.688×10-19 mg/molecule × 1.6×1017 molecules = 9.101 mg
Therefore, the mass of the sugar crystal is approximately 9.101 mg.

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Answer:

Cyanosis

Explanation:

Cyanosis is purplish or bluish discolouration of skin or the mucous membranes. The presence of the cyanosis occurs due to the increased quantity of the deoxyhemoglobin and the haemoglobin is not combined with the oxygen. The tissues near the surface of the skin become to have low oxygen saturation. The first signs of the cyanosis can be seen on lips or fingers or finger nails.

Answer:

A.

Explanation:

For a process that occurs at constant temperature and pressure, spontaneity can be determined using the change in Gibbs free energy, which is given by:

ΔG = ΔH - TΔS. A process is spontaneous if ΔG≤O.

Even so the enthapy of the dissolution is positive the factor -TΔS will produce a negative ΔG  value. As ΔS is relatived to the disorder of a system, a increase in this value (ΔS ) upon dissolution will made the dissolution process spontaneous.

The dissolution of NH4NO3 in water is endothermic but spontaneous due to the increase in disorder (entropy) when the compound dissolves and ionizes. This aligns with the second law of thermodynamics which states that systems tend towards increased disorder.

The dissolution of ammonium nitrate (NH4NO3) in water is spontaneous despite being endothermic due to an increase in disorder or entropy upon dissolution. In a spontaneous process, the universe tends towards increased randomness or disorder, which is a central concept in the second law of thermodynamics.

When ammonium nitrate dissolves in water, it ionizes into its component ions, which increases the entropy of the system. The positive enthalpy change (which indicates endothermic dissolution) is offset by this sufficiently large increase in entropy, allowing the dissolution to be spontaneous even though it absorbs heat.

Therefore, the correct answer is option A: 'The solution process is spontaneous because of the increase in disorder upon dissolution of this strong electrolyte.'

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Answer:

As the silver chloride is an insoluble compound in water, I can apply heat to water to make it evaporate and recover the chloride. You can also apply a filtration process to remove the liquid or centrifuge so the chloride can precipitate and remains at the bottom of the tube

Explanation:

Answer:

There are some physical separation methods that can help

Explanation:

Hi, given that the silver chloride is unsoluble in water it can be separated by physical means. Such as:

1) Filtration: this is the best option if you want to keep the water and not he salt.

Note: you can separate the salt from the filter by calcination

2) Centrifugal force: by applying centrifugal force to a test tube with the mixture, the unsoluble salt will precipitate.

3) Evaporation: if your product of interest is the salt, you can always apply heat to evaporate all the water. The salt will remain in the test tube.

The answer you're looking for is

It is formed when an atom loses electrons.

Explanation ??

Well, the electrons are the negative part of an atom right? And protons are the positive part of the atom! We learned that when all of us were younger and first learning about atoms. The main reason it isn't "It is formed when an atom gains protons" is because most atoms have protons, it can still be negative as long as it has more electrons than protons. So that leaves us with, "It is formed when an atom loses electrons." I believe this is correct because since it is losing electrons, it is losing the negativity!

(( Max ))

A positively charged ion is formed during reactions when an atom loses

electrons.

During chemical reactions, electrons are lost and gained as elements strive

to obtain a stable octet configuration. This is done through series of bonding techniques and processes such as covalent bond etc.

When an atom loses electrons it becomes a positively charged ion and

when an atom gains an electron it becomes negatively charged.

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Answer:

Water of solution A will go through membrane until solution B.

Explanation:

That phenomenon occurs by mass transfer.

Mass transfer is the movement from a location to another that occurs when you have mass gradient. In a membrane with different concentration solutions the system will try to equal both concentrations.

In the problem, Solution B is more concentrated than A. Thus, water will transport from solution A to solution B increasing concentration of A and decreasing concentration of B until the system stay in equilibrium.

I hope ot helps!

Osmosis is the diffusion of water through a semipermeable membrane. In this case, water will move from Solution A to Solution B.

Osmosis is the diffusion of water through a semipermeable membrane down its concentration gradient.

In this case, the membrane is permeable to water but not salts.

Solution A is a 2% NaCl solution and Solution B is a 3% NaCl solution. Since water moves from an area of higher water concentration to one of lower concentration, water will move from Solution A to Solution B.

This will cause Solution B to become diluted and Solution A to become more concentrated.

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a) The total weight of the resulting mixture is 128 grams.

b) The percentage of the resulting mixture is copper is 81.25% copper.

a) Weight of alloy with 52% copper = 50 grams

Weight of pure copper = 78 grams

Total weight of resulting mixture = Weight of alloy + Weight of pure copper

                                                      = 50 grams + 78 grams

                                                      = 128 grams

So, the resulting mixture contains 128 grams.

b) To find the percentage of copper in the resulting mixture, you can use the following formula:

Percentage of copper = (Total weight of copper / Total weight of mixture) × 100

Total weight of copper = Weight of copper in alloy + Weight of pure copper

                                      = (52% of 50 grams) + 78 grams

                                      = 26 grams + 78 grams

                                      = 104 grams

Now, Percentage of copper = (104 grams / 128 grams) × 100

                                               = 81.25%

So, the resulting mixture contains 81.25% copper.

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The resulting mixture weighs 104 grams and contains 25% copper.

To calculate the grams in the resulting mixture, we need to add the masses of the two components. The alloy contains 50 grams of a 52% copper alloy, which means it contains 0.52 * 50 = 26 grams of copper. The pure copper weighs 78 grams. Adding these two masses together, we get:

Total mass of resulting mixture = 26 grams + 78 grams = 104 grams

To calculate the percentage of copper in the resulting mixture, we need to divide the mass of copper by the total mass of the mixture and multiply by 100. Using the values we calculated earlier:

Percentage of copper in resulting mixture = (26 grams / 104 grams) * 100 = 25%

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Answer:

The three blanks for this answer, are

1. volumen

2. moles

3. Temperature and pressure.

So, Avogadro's law states that the volume of a gas is directly proportional to the moles of the gas when temperature and pressure stay the same

Explanation:

Imagine you have 10 moles of a gas which is contained in 50 L. How many moles of that gas, you will have if the volumen has been reduced to 10 L. (Of course, don't forget that T° and pressure are the same)

There is an equation like this, initial moles /initial volume = moles at the end/volume at the end, (Avogadro law for gases), so 10/50 =moles at the end/10.  When u operate, moles at the end = (10 x 10) / 50.

Moles at the end are 2. Did u get it?. Volumen has been reduced, also the moles.

Avogadro's law states that the volume of a gas is directly proportional to the amount of the gas when temperature and pressure stay the same.

Avogadro's law states that the volume of a gas is directly proportional to the amount (moles) of the gas when temperature and pressure stay the same. This law is based on Avogadro's principle which states that equal volumes of gases, at the same temperature and pressure, contain an equal number of particles (atoms, molecules, or ions).

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Answer:

The answer to yourquestions is the last option

Explanation:

Cr(s) -------------------- Cr +3 (aq) + 3e-

Answer:

They will repel because they both carry negative charges.

Explanation:

When water approaches hydroxide ions, the oxygen atoms will repel each other. Water on its own is a polar covalent compound. It has a positive and negative end.

Hydroxide is radical that is negatively charged. It consists of oxygen and hydrogen atoms.

The like charges on the oxygen atom will repel one another as a general rule of attraction. The oxygen will have more affinity for the hydrogen.

The isotopic mass of 123Sb can be calculated using the equation for atomic weight, taking into account the percentage abundance of each isotope of antimony. Solving this equation, the isotopic mass of 123Sb is determined to be approximately 122.93 u.

To calculate the isotopic mass of 123Sb, we should make use of the equation that defines atomic weight. The atomic weight is the weighted average of the isotopic masses, factoring in the percentage abundance of each isotope.

The equation can be represented as follows:

Atomic weight = (mass isotope 1 x percentage abundance isotope 1) + (Mass isotope 2 x percentage abundance isotope 2)

Plugging in the known values,

121.75 u = (120.9038 u x 57.25%) + (Mass 123Sb x (100% - 57.25%))

By rearranging the equation and solving it, we can find the mass of 123Sb to be around 122.93 u

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Answer:

C)

Explanation:

The fats can be saturated or unsaturated. Saturated fats have only simple bonds between atoms of carbon. The unsaturated fats have one or more double bonds between atoms of carbon.

When there are double bonds in the carbon chain, the molecule can have geometric isometric, if the carbons of the double bond have different binders. The isomers are named cis and trans. The cis molecule has the equivalent atoms or structures (the same or mass equivalent) on the same side of the plan of the molecule. The trans molecule has this equivalent atoms or structures in the opposite side of the plan of the molecule (see figure below)

It happens in a way to stabilize the molecule. So, the trans fat, because of its disposition, has straightened the hydrocarbon chain, almost like the saturated molecule, then, they have similar characteristics.

Since, fluorine is an electronegative element ,therefore it is most likely to gain an electron ,so option (b) is correct.

Electronegativity is referred to as a chemical property that describes the tendency of an atom of an element to attract shared electrons while forming a chemical bond.

Electronegativity of elements across a period-

As we move from left to right through a period in the modern periodic table, the nuclear charge increases and the atomic size decreases, as a result it increases the value of electronegative elements.

Fluorine has the highest electronegativity element on periodic table.

Hence it concludes that  fluorine is an electronegative element ,and it is most likely to gain an electron ,so option (b) is correct.

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Answer:

The concentration of the hydroxide ion concentration for muriatic acid is 3.16 * 10^-12 M

Explanation:

Muriatic acid = HCl

pH = 2.5

pH = -log[H+]

pOH = 14 - pH

pOH = 14 - 2.5 = 11.5

pOH = -log [OH-]

11.5 = -log [OH-]

[OH-] = 10^-11.5

[OH-] = 3.16 * 10^-12 M

The concentration of the hydroxide ion concentration for muriatic acid is 3.16 * 10^-12 M

Answer:

Explanation:

Given the characteristics:

acetone is a non polar molecule

water, NaOH and HCl in water, the three of them are highly polar molecules

So then, the unknown compound is a non polar molecule.

To determine the mass of the sample, first find the volume difference after and before the aluminum was placed, the volume change is equal to the volume of the submerged object, in this case aluminum.

Then knowing volume of aluminum and the density of it, we can solve for the mass.

D = m/v

Dv = m

2.7 g/ml • 8 ml = 21.6 grams.

Answer: The mass of sample is 21.6 grams.

Explanation:

We are given:

Volume of cylinder without object, [tex]V_1[/tex] = 10 mL

Volume of cylinder with object, [tex]V_2[/tex] = 18 mL

Volume of object = [tex]V_2-V_1=18-10=8mL[/tex]

To calculate volume of a substance, we use the equation:

[tex]\text{Density of a substance}=\frac{\text{Mass of a substance}}{\text{Volume of a substance}}[/tex]

We are given:

Density of sample (aluminum) = 2.7 g/mL

Volume of sample (aluminum) = 8 mL

Putting values in above equation, we get:

[tex]2.7g/mL=\frac{\text{Mass of a sample}}{8mL}\\\\\text{Mass of object}=21.6g[/tex]

Hence, the mass of sample is 21.6 grams.

Final answer:

Robert A. Millikan's oil-drop experiment validated the charge on an electron. He determined the fundamental electric charge by analyzing the behavior of electrically charged oil droplets in an electric field.

Explanation:

In 1909, Robert A. Millikan's pioneering oil-drop experiment led to a major advancement in our understanding of atomic structure. Millikan was able to measure the electric charge on microscopic oil droplets, which he had electrically charged. By analyzing the behavior of these drops in the presence of an electric field and by balancing the gravitational and electrical forces, he could determine the charge on the droplets.

The significance of Millikan's findings is that he validated the existence of a fundamental electric charge, which is the charge of an electron. His experiments did not directly measure the charges on protons or the masses of protons or atoms, and while he later used the charge of the electron to calculate its mass, the oil-drop experiment itself did not directly validate the mass of an electron.

Therefore, from the options provided, Millikan's oil-drop experiments specifically validated 3. charge on an electron.

Answer:

C

Explanation:

Atoms undergoing alpha decay lose 2 protons and two neutrons to become a different atom. Those two protons and neutrons are represented by an α (the symbol for alpha) particle which also represents a helium nucleus (2 neutrons and 2 protons).  

Answer:

The naswer to your question is Scandium

Explanation:

43 means the atomic mass is normally presented as a power

21 means atomic number is always a subscript

                   ₂₁ ? ⁴³

Technetium             ₄₃Tc⁹⁸

Scandium                 ₂₁Sc⁴⁴      

Titanium                   ₂₁Ti⁴⁷

Cobalt                      ₂₇Co⁵⁹

Answer:

B. Scandium is the answer

Explanation:

[tex]Sc^{43}_{21}[/tex]

When we look at this Nuclide symbol we get to know that 21 is the atomic number as it is in the subscript and 43 is the mass as it is in the superscript.

We identify an element from its atomic number by looking at the periodic table.

Atomic number 21 is element Scandium. Sc-43 is one of the isotope mentioned here.

We don’t use mass number to identify an atom.