I rlly need help with my science hwk its due in tomorrow and I am stuck can any one help me plzz :)






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Mendeleev is given the most credit for the concept of a periodic table of the elements because he emphasized its usefulness in predicting the existence and properties of unknown elements.

This is referred to as a tabular arrangement of the chemical elements by increasing atomic number which displays the elements so that one may see trends in their properties.

It consists of a rows and columns arrangement of the chemical elements and each they are grouped according ti the similar features which are present in the elements.

Mendeleev was the scientist who was given the most credit for the concept of a periodic table of the elements despite others working on it previously as a result of his emphasis in its usefulness in predicting the existence and properties of unknown elements.

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Answer: ahem...

Explanation: 1. True 2. reproducing 3. All of them 4. i would say true, the only thing is plants dont really digest food and it says "all" organisms... 5. B, C, and D...A is more of defense and not really "maintaining structure"

Answer:

89-91=1 the answer is 1molar mass

Answer:

no

Explanation:

Answer:

Its A

Explanation:

The structure that corresponds to the name 4-chloro-3-ethyl-2-hexene​based on IUPAC nomenclature is option A is correct.

In organic chemistry is a method of naming organic chemical compounds as recommended by the International Union of Pure and Applied Chemistry (IUPAC).

The Word root of the name indicates the number of carbon atoms in the longest possible continuous carbon chain also known as the parent chain stucture.

The primary suffix structure  is used to indicate the degree of saturation or unsaturation in the main chain. A secondary suffix is used to indicate the main functional group in the organic structure and is added immediately.

The 1o suffix in the name and the prefix are used to indicate the side chains, substituents, and low-priority functional groups which are considered as substituents.

Therefore, the name is  4-chloro-3-ethyl-2-hexene​ option A is correct.

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Answer & Explenation:

2H2 + O2 -> 2H20 is the balanced equation for the reaction of Hydrogen with Oxygen to form water so

If you have 32g of O2 this is a simple Dimensional analysis problem

32g O2 x 36.03056g H20/31.9988g O2 this way the O2 cancels out and you are left with just the H2O so your raw answer would be 36.0319112, then if your instructor requires a significant figure answer that would be to 2 significant figures the information you were given 32g O2, so as above 36g or Water are produced. Just a different way to view and solve the problem with the balanced equation so you can see the way everything relates to everything else. the molar masses of O2 and H2O are simply found my adding up 2 Oxygens 15.9994g x2 = 31.9988g and H2O = 2(1.00794) + 15.9994 = 18.01258 but you then have to multiply that by 2 because the reaction states you get 2 mols in the reaction so that is where I came up with the 36.03056g for the solution. Hope this helps. Dimensional Analysis is and can be one of the best ways to solve these problems, because not always are you going to be dealing with 1:2 ratios.

the partial pressure of gas A in the total volume is 3.57 bar, and the partial pressure of gas B in the total volume is 0.70 bar.

When the gases are allowed to mix together, the total pressure of the mixture is equal to the sum of the partial pressures of each gas. The partial pressure of each gas is equal to the product of the total pressure and the mole fraction of that gas. To find the mole fraction of each gas, we first need to find the number of moles of each gas. The number of moles of gas in container A is given by PV/RT where P is the pressure, V is the volume, R is the ideal gas constant and T is the temperature.

n_A = (2.90 bar * 747 mL) / (8.314 J/molK * (273.15 + 23)) = 0.0295 mol

The number of moles of gas in container B is given by PV/RT

n_B = (4.30 bar * 119 mL) / (8.314 J/molK * (273.15 + 23)) = 0.0045 mol

The total number of moles of gas in the mixture is the sum of the number of moles of gas in container A and container B.

n_total = n_A + n_B = 0.0295 mol + 0.0045 mol = 0.0340 mol

The mole fraction of gas A in the mixture is the number of moles of gas A divided by the total number of moles of gas.

x_A = n_A / n_total = 0.0295 mol / 0.0340 mol = 0.8735

The mole fraction of gas B is

x_B = n_B / n_total = 0.0045 mol / 0.0340 mol = 0.1324

The partial pressure of gas A is equal to the total pressure multiplied by the mole fraction of gas A.

P_A = (0.8735) * (2.90 bar + 4.30 bar) = 3.57 bar. The partial pressure of gas B is equal to the total pressure multiplied by the mole fraction of gas B. P_B = (0.1324) * (2.90 bar + 4.30 bar) = 0.70 bar

So the partial pressure of gas A in the total volume is 3.57 bar, and the partial pressure of gas B in the total volume is 0.70 bar.

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Answer:

45 km

Explanation:

To find the distance Tylee walked, multiply her speed by the time.

[tex]d=10(4.5)[/tex]

[tex]d =45[/tex]

The distance Tylee walked is 45 kilometers.

I hope this helped :)

Tylee walked 45 km from her parents' farm into town .

Speed can be understood as the measure of  how fast an object is moving.

It is the rate at which an object covers certain distance in fixed amount of time.

It is scalar quantity and its S.I. unit is m/sec .

[tex]\rm Speed = \dfrac{distance}{time}[/tex]

It is given in the question speed = 10 km/h and time = 4.5 hr

So,

[tex]\rm Distance = Speed\; \times\;time[/tex]

[tex]\rm Distance = 10\; \times\;4.5\\\\\rm Distance = 45 \;km\\[/tex]

Therefore Tylee walked 45 km from her parents' farm into town .

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The density of the metal beads, given that total mass of the metal plus alcohol in the flask was determined to be 38.6794 g is 3.22 g/mL

We'll begin by obtaining the density of the alcohol in the flask with the metal beads. This is illustrated below:

Density = mass / volume

Density of alcohol = 19.7325 / 25

Density of alcohol = 0.7893 g/mL

Next, we shall determine the volume of the alcohol in the 25 mL flask. This can be obtained as follow:

Volume = mass / density

Volume of alcohol in flask = 13.5734 / 0.7893

Volume of alcohol in flask = 17.2 mL

Finally, we shall determine the density of the metal beads. Details below:

Density = mass / volume

Density of metal beads = 25.1060 / 7.8

Density of metal beads = 3.22 g/mL

Thus, we can conclude that the density of the metal beads is 3.22 g/mL

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Complete question:

A calibrated flask was filled to the 25.00 mL mark with ethyl alcohol. By weighing the flask before and after adding the alcohol, it was determined that the flask contained 19.7325 g of alcohol. In a second experiment, 25.1060 g of metal beads were added to the flask, and the flask was again filled to the 25.00 mL mark with ethyl alcohol . The total mass of the metal plus alcohol in the flask was determined to be 38.6794 g. What is the density of the metal in g/mL?

Carbon 1: δ = 2.09 ppm (The C1 atom is a methyl group, and is in a tertiary environment, which typically corresponds to a chemical shift of around 2.09 ppm).

Chemical shift is a term used in NMR spectroscopy to describe the relative difference in the resonance frequency of a nucleus in a molecule compared to a reference frequency.

2. Carbon 2: δ = 11.81 ppm (This is the carbonyl carbon, and is in a sp2 hybridized environment, which typically corresponds to a chemical shift of around 11.81 ppm).
3. Carbon 3: δ = 13.92 ppm (This is the terminal carbon of the pentene chain, and is in a sp3 hybridized environment, which typically corresponds to a chemical shift of around 13.92 ppm).
4. Carbon 4: δ = 16.53 ppm (The C4 atom is a methylene group, and is in a secondary environment, which typically corresponds to a chemical shift of around 16.53 ppm).
5. Carbon 5: δ = 17.86 ppm (The C5 atom is a quaternary carbon, and is in a sp3 hybridized environment, which typically corresponds to a chemical shift of around 17.86 ppm).

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Option (4) is correct. The rate constant of a second order reaction has the unit  L/mole. sec.

In the Second order reaction the rate is proportional to the square of the concentration of one reactant. Rate of Second order reaction  is proportional to the product of the concentrations of two reactants. Such reactions generally have the form,

A + B → products.

Each monomer combines to form a larger molecule is called dimer. For the units of the reaction rate to be moles per liter per second (M/s), the units of a second-order rate constant must be the inverse (M−1·s−1). Because the units of molarity are expressed as mole/L, the unit of the rate constant can also be written as L(mole ·s).

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After 4 minutes, 200 g of protactinium-234 would remain.

Protactinium-234 is a radioactive isotope of protactinium. It is a fission product that is produced when uranium atoms undergo fission. It has a half-life of 1.17 minutes and decays via beta-decay to uranium-234. It is the most stable isotope of protactinium and is found in very small quantities in uranium ore. The main uses for protactinium-234 are for research, nuclear medicine and nuclear power. In research, it can be used to study properties of fission products and to measure the efficiency of nuclear reactors. In nuclear medicine, it can be used to detect cancers and other conditions. Finally, it can be used in nuclear power plants to help regulate and control the flow of energy.

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Answer:

Answer Below

Explanation:

Answer: 8.4322×1024atoms atoms are in 1.4 moles of cadmium. Cadmium is present in some foods and is emitted when fossil fuels like as coal and oil is used, smoking cigarettes.

Answer:

The answer is 8.4308 × 10²³ atoms

Explanation:

Multiply by Avogadro's number (Nₐ)

Nₐ = 6.022 × 10²³ mol⁻¹

Now,

1.4 × 6.022 × 10²³ = 8.4308 × 10²³

Thus, 8.4308 × 10²³ atoms are in 1.4 moles of Cadmium.

A sample of methane collected when the temp was 30 C and 760mmHg measures 398 mL. What would be the volume of the sample at -5 C and 616 mmHg pressure

434.32mL

Using the combined gas law:

[tex]\frac{PV}{T}[/tex] = k

Where;

P = Pressure

V = Volume

T = Temperature

k = constant.

It can be deduced that:

[tex]\frac{P_1V_1}{T_1}[/tex] = [tex]\frac{P_2V_2}{T_2}[/tex] = k           ---------------------(i)

Where:

P₁ and P₂ are the initial and final pressures of the given gas

V₁ and V₂ are the initial and final volumes of the given gas

T₁ and T₂ are the initial and final temperatures of the gas.

From the question:

the gas is methane

P₁  = 760mmHg

P₂ = 616mmHg

V₁ = 398mL

V₂ = ?

T₁ = 30°C = (30 +273)K = 303K

T₂ = -5°C = (-5 +273)K = 268K

Substitute these values into equation (i) as follows;

[tex]\frac{760*398}{303}[/tex] = [tex]\frac{616*V_2}{268}[/tex]

Solve for V₂

V₂ = [tex]\frac{760*398*268}{616*303}[/tex]

V₂ = 434.32mL

Therefore, the volume of the sample at -5C and 616mmHg pressure is 434.32mL

Answer:

the number of protons and neutrons at both terminals are equal

Explanation:

When the number of positive charge and negative charge are both equally the terminal, it becomes neutral and out of charge, because first it undergo enough chemical reaction and there is no remaining tendency for positive and negative charges to get separated. When this tendency dies, the battery also will run out of charge.

The student collected data on the mass of each artificial cell. The student predicted that the cell in the beaker with 25% sugar solution would have the greatest change in mass after 24 hours. The student's prediction would be correct.

The artificial cell placed in the beaker with 25% sugar solution would likely have the greatest change in mass after 24 hours because of osmosis.

Osmosis is the movement of water across a semi-permeable membrane from an area of high water concentration to an area of low water concentration. In this case, the artificial cell has a semi-permeable membrane that allows water to pass through, but not sugar.

The 25% sugar solution in the beaker is less concentrated than the sugar solution inside the artificial cell, so water will move from the beaker into the cell, causing the cell to swell and increase in mass.

On the other hand, the artificial cells in the beakers with 0% and 12.5% sugar solutions will have less of a change in mass as the solution outside of the cell is more concentrated than inside the cell.

Therefore, the correct answer is as given above

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The pressure of N2O gas at a density of 3.10 g/L and a temperature of 298 K is 751 mmHg. To calculate the pressure of the N2O gas at a given density and temperature, we can use the ideal gas law: PV = nRT.

We know that the density of the gas is 3.10 g/L, and the temperature is 298 K. To find the pressure, we can assume that the volume of the gas is 1 L, and solve for pressure. where P is the pressure of the gas, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.

The density of a gas can be converted to moles using the formula:

Density = m/V

m = Density*V

Now we can use the ideal gas law to calculate the pressure:

P = (mRT)/V

R is the ideal gas constant = 0.0821 L atm K^-1 mol^-1

P = (3.10g0.0821 L atm K^-1 mol^-1298 K)/1 L

P = 751 mmHg

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Answer:

yes they are same thing by E=MC^2 EINSTEIN'S EQUATION

Answer:

True.

Explanation:

The mass of these three particles is less than the mass of a neutron, so they each get some energy as well. So energy and matter are really the same thing. Completely interchangeable. And finally, Although energy and mass are related through special relativity, mass and space are related through general relativity.

So energy and matter are really the same thing. Completely interchangeable. And finally, Although energy and mass are related through special relativity, mass and space are related through general relativity. ... So in a way, energy, matter, space and time are all aspects of the same thing.

The pieces of information a chemical equation includes are:

A chemical equation is a graphical representation of a chemical process that employs symbols and chemical formulas. Reactant entities appear on the left, as well as product entities appear on the right, with a plus sign connecting the entities in both the reactants and the products and an arrow pointing towards the products to show the direction of the reaction.

Chemical formulae can be symbolic, structural (pictorial diagrams), or a combination of the two. The absolute values of the stoichiometric numbers are represented by the coefficients adjacent to the symbols and formulae of entities. Jean Beguin drew the very first chemical equation in 1615.

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Explanation:

decentralized multinational corporations, centralised global corporations, international companies, and transnational enterprises.

Answer:

Hey mate.....

Explanation:

This is ur answer....

Vinegar is a compound and a mixture, being mainly acetic acid (compound)mixed into water (another compound).

Hope it helps!

Brainliest pls!

Follow me! :)

Answer:

Vinegar is an example of a homogeneous mixture, and not a pure substance since water, its solute, is dissolved in the solvent, being acetic acid. Homogeneous mixtures are also known as solutions, which are mostly composed of liquids (including vinegar), but can include gases.

The law that demonstrates this observation is the law of definite proportions.

Law of definite proportion states that a given chemical compound continually incorporates its element factors in constant ratio (with the aid of using mass) and does now no longer rely on its supply and technique of preparation. Law of Definite Proportions states that during a given kind of chemical substance, the factors are continually blended withinside the identical proportions with the aid of using mass. The Law of Definite Proportions applies while factors are reacted collectively to shape the identical product. Such as , a sample of an unknown substance contains 24. 0 grams of carbon and 2. 0 grams of hydrogen.

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Answer:

It combines vigorously with chlorine on mild heating and also with a variety of other nonmetals, including all of the halogens, sulfur, phosphorus, boron, carbon, and silicon (the carbide and silicide phases play major roles in the technical metallurgy of iron). Metallic iron dissolves readily in dilute mineral acids.

Explanation:

Iron is the chemical species that is the most used metal and is often found attached to the chlorine element.

Iron metals react with many elements and are an abundant element in the Earth's crust. It combines with the chlorine element when subjected to mild heating.

Along with chlorine it also reacts with halogen groups, carbon, sulfur, silicon, etc. This application is used in the metallurgy of iron.

Therefore, iron is joined to chlorine.

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100 cm is meter stick.

Centimeter is denoted by the (cm). It is a metric unit of the measurement which is used for measuring the length of an object.

Meterstick is a foldable ruler which is used to measure the length, and it is common in the construction industry. They are made up of wood or plastic and often they have a plastic or metal joints so that they can be folded together.  

A meter measuring stick, which is one meter (39.37 inches) long, it contains 100 centimeters. Thus, centimeter is equal to one-hundredth of a meter. The word centimeter comes from the late 18th-century. The word centimeter derived from the Latin root "centum"/ means "hundred" and the Greek root "metron", meaning "measure".

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Statement about isomers which is true is that isomers have the same chemical formula, but different structures.

Chemical  formula is a way of representing the number of atoms present in a compound or molecule.It is written with the help of symbols  of elements. It also makes use of brackets and subscripts.

It is not the same as structural formula and does not have any information regarding structure.It does not provide any information regarding structure of molecule as obtained in structural formula.

There are four types of chemical formula:

1)empirical formula

2) structural formula

3)condensed formula

4)molecular formula

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the chemical equation will be XY2

The unit of f''(a) is milliliters/minute^2

The function t=f(a) models the time, in minutes, for a chemical reaction to occur as a function of the amount a of catalyst used, measured in milliliters.

So, here double differentiation is to be done.

t=f(a)

differentiating with respect to t,

d(t)/dt = d(f'(a))/dt

or, d(f'(a))/dt = 1

again differentiating with respect to t,

d [d(f'(a))/dt]/dt = d(1)/dt = 0 ...1

or, f''(a) = 0

so, here if we put 'unit expression' in Left hand side of 1

it is d [d(f'(a))/dt]/dt  i.e.  mililiters/miniute/minute [as given t is measured in minute and f(a) is measured in ml)

or, ml/minute^2

so as we are performing double differentiation, the unit of f''(a) is milliliters/minute^2

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Answer:

Mutualism

Explanation:

A relationship in which both benefit

The simplest formula for a compound is made up of 1.677 grams of iron and 0.640 grams of oxygen would be FeO.

What the question is asking here is the empirical formula of an oxide of iron made up of 1.677 grams of iron and 0.640 grams of oxygen. The empirical formula shows the formula in the simplest whole-number ratio of the atoms.

Iron (Fe) = 1.677 grams

Oxygen (O) = 0.640 grams

Converting the masses to moles:

Fe = 1.677/56 = 0.0299 mol

O = 0.640/16 = 0.0400 mol

Now, let's divide by the smallest mole:

Fe = 0.0299/0.0299 = 1.0

O = 0.0400/0.0299 = 1.3

Thus, the empirical formula of the oxide of iron is FeO.

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Answer:

1. P

2. A/B

3. A/B

4. R/O

5. P

6. R/O

7. A/B

8. P

9. R/O

10. R/O

Explanation:

Precipitation:

Ag (aq) + HCl (aq) → H₂ (g) + AgCl↓

Precipitation reactions can contain a single element.

Certainly, two soluble solutions are mixed, forming an insoluble solid.

Reactions can be identified using a solubility chart, because solubility can affect the precipitacion's equilibrium.

Acid base:

Certainly you mix an acid(H+) an a base (OH-)

We talk about neutralization because we make water. And, there is also a formed salt.

HNO₃  +  KOH →  H₂O  + KNO₃

H⁺  +  OH⁻  ⇄  H₂O    Kw

Redox:

This is the reaction where moles of electrons are transferred and gained.

A pure element is consumed or formed. We have 2 half reactions:

- Reduction (oxidation state decreases, electrons are released)

- Oxidation (oxidation state increases, electrons are gaines)

Reactions involving pure O₂ are named combustion, which is a redox type.

This is an example of redox decomposition of hydrogen peroxyde.

2H⁺  +  H₂O₂  + 2e⁻  →  2H₂O

H₂O₂  →  2H⁺  +  O₂  + 2e⁻  

H₂O₂  →  2H₂O  +  O₂