In 2011, the number of transplants in the United States was 26,745, and the number of donors was 14,146. What is most likely the reason that there were more transplants than donors? The data that were used for comparison was not compatible. O The data were not recorded accurately There were retransplants done. © Each donor gave away more than one organ.​

Answer:

There are 6.022x10^23

Explanation:

plzz put me as brainest

Answer:

B

Explanation:

I hope it helps you good luck

Answer:

3 * 10^-4  μg

Explanation:

Molar mass of Hg2Cl2 = 472.09 g/mol

Now;

number of moles = mass/molar mass = concentration * volume

So;

n =m/M = CV

m = MCV

C = 3.75 x 10^−6/μmolL or 3.75 x 10^−12 molL-1

M =472.09 g/mol

V= 170.0mL

m = 3.75 x 10^−12  * 472.09 * 170.0/1000

m = 3 * 10^-10 g or 3 * 10^-4  μg

Answer:

Solar energy is essentially the light and heat emitted from the sun

Answer:

Alkali Metals: •are placed in group 1, • can be cut with a knife

Halogens: •are placed in group 17, • react vigorously with metals

Explanation:

Alkali metals are the metals found in group 1 of the periodic table. They have one outermost shell electron. They react with cold water vigorously to form alkalis and liberate hydrogen gas as well. They are very reactive metals and their reactivity increases on going down the group. They are soft and can be cut with a knife. Examples of alkali metals are lithium, sodium,potassium, rubidium,caesium, francium.

The Halogens are reactive non-metals placed in group 17 of the periodic table. They have seven outermost shell electrons. They are the most reactive non-metals react vigorously with metals by to form ionic compounds. They exist as diatomic molecules. They are found in nature mainly as salts because of their reactivity. Their reactivity decreases on going down the group. Examples of the halogens include fluorine, chlorine, bromine, iodine and astatine.

Answer:

B

Explanation:

Got it right on a quiz

The list that is in order from smallest to biggest is Nebula-Galaxy -Solar system - Universe. The correct answer is option C.

A nebula is a cloud of gas and dust in space, which is the smallest object in the list.

A galaxy is a collection of stars, gas, and dust held together by gravity, which is larger than a nebula.

A solar system is a collection of planets and other objects that orbit a star, which is larger than a galaxy.

The universe is the largest entity in the list, comprising all matter and energy in existence.

Therefore, option C.  Nebula-Galaxy -Solar system - Universe is the correct order of the list from smallest to biggest.

Learn more about nebula here:

https://brainly.com/question/9497068

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Answer:

Atoms are electrically neutral because they have equal numbers of protons (positively charged) and electrons (negatively charged).

Explanation:

Answer:

See answer below

Explanation:

In this case, I will put the original photo of this exercise, because we are missing one data. The first picture is the original exercise.

Now, according to this, we need to make a serial dilution of CO(NO₃)₂. We don't know the volume of this solution, but we do know the total volume of the preparing solution (In the picture states that the total volume will be 10 mL).

So, we know the final volume of the solutions to be prepared, so, le'ts use the expression that will help us to solve this:

C₁V₁ = C₂V₂

Where:

C₁: Concentration of the given solution (stock)

V₁: volume required to prepare the dilluted solution

C₂; Concentration of the dilluted solution

V₂: Total volume of the dilluted solution.

Now that we know the expression to use and the meaning of each value, let's prepare the solutions:

To prepare 10 mL of 0.1 M using a 0.25 M, we will replace these values in the above expression; from there, we will solve for V₁, that value will tell us the required volume to prepare solution 2, and then, by difference we can calculate the volume of water:

Volume of water (Vw) =V₂ - V₁  

Now replacing the values:

0.25V₁ = 0.1 * 10

V₁ = 1/0.25 = 4 mL

This means that we need 4 mL of the stock to prepare the 0.1 M of dilluted solution, therefore, the volume of water required is:

Vw = 10 - 4

Using these same steps for the other two solutions we will get V1 and V2 for both of them. In this case, I will go straight to the procedure without further explanation because it's the same of this one.

For solution 2:

0.1V₁ = 0.05 * 10

V₁ = 0.5/0.1

Vw = 10 - 5

Finally for solution 3:

V₁ = 0.01 * 10 / 0.05

Vw = 10 - 2 mL

Hope this helps

Heat produced =  -13588.956 kJ

Given

The reaction of combustion of Methane

CH4(g)+2O2(g)→CO2(g)+2H2O(g) ΔH∘rxn=−802.3kJ

271 g of CH4

Required

Heat produced

Solution

mol of 271 g CH₄ (MW=16 g/mol0

mol = mass : MW

mol = 271 : 16

mol = 16.9375

So Heat produced :

= mol x ΔH°rxn

= 16.9375 mol x −802.3kJ/mol = -13588.956 kJ

The question is incomplete, the complete question is;

In the 1800s, a popular belief known as vitalism stated that life processes could not be explained by the laws of physics and chemistry,and were instead dictated by an independent life force. Which discovery most likely caused scientists to revise this hypothesis regarding the origin of life on Earth?

a. that inorganic compounds existed within live organisms

b. that organic compounds could be synthesized in a laboratory

c. that RNA could serve as a template to synthesize DNA

d. that self-replicating molecules existed inside cells

Answer:

b. that organic compounds could be synthesized in a laboratory

Explanation:

Vitalism is the belief that "living organisms are fundamentally different from non-living entities because they contain some non-physical element or are governed by different principles than are inanimate things"(wikipedia).

This theory held that the molecules involved in life processes could not be synthesized in the laboratory.

All these were upturned after Fredrich Whöler's synthesis of urea in 1828. He was able to show that molecules involved in life process can also be synthesized in the laboratory. This gave rise to modern synthetic organic chemistry.

Answer:

Physical Change. A change of matter from one form to another without a change in chemical properties. Chemical Change. A change that occurs when one or more substances change into entirely new substances with different properties.

Explanation:

Answer:

- Oil Energy is a Major Source of Pollution and Damage Made to the Environment Every Year.

- Oil Like the Other Fossil Fuels Is A Finite Resource.

- Emissions Produced by Oil Causes Acid Rain

-Plastic is One of the Products Obtained Through Oil Refining.

- Working in the Oil Sector Can Be a Dangerous Activity.

hope this is good enough :)

Answer:

Pros: Oil can easily be transported by a network of pipelines.

Oil-fired power stations can, in theory, be built almost anywhere.

The oil is burned to heat water and produce steam. This steam propels the blades of a turbine. This is attached to a generator, which produces electricity.

Cons: Oil is a non-renewable source of energy. This means that one day we will probably run out of crude oil.

Burning oil produces carbon dioxide gas. This is a greenhouse gas that contributes towards climate change.

Burning oil can pollute the air.

Much of our oil has to be imported and it is becoming more and more expensive as reserves reduce and imports increase.

Producing electricity from crude oil is expensive compared to other fossil fuels such as coal or gas.

Explanation:

Answer:

You will form a solution

Explanation:

The sugar is added into the water, then the sugar will dissolve into the water.

Answer: deposition

extra words lol

Answer:

(I'm not sure tbh) It's C Polypeptides are formed by 10 or more amino acids

Answer:

No, it is not sufficient

Please find the workings below

Explanation:

Using E = hf

Where;

E = energy of a photon (J)

h = Planck's constant (6.626 × 10^-34 J/s)

f = frequency

However, λ = v/f

f = v/λ

Where; λ = wavelength of light = 325nm = 325 × 10^-9m

v = speed of light (3 × 10^8 m/s)

Hence, E = hv/λ

E = 6.626 × 10^-34 × 3 × 10^8 ÷ 325 × 10^-9

E = 19.878 × 10^-26 ÷ 325 × 10^-9

E = 19.878/325 × 10^ (-26+9)

E = 0.061 × 10^-17

E = 6.1 × 10^-19J

Next, we work out the energy required to dissociate 1 mole of N=N. Since the bond energy is 418 kJ/mol.

E = 418 × 10³ ÷ 6.022 × 10^23

E = 69.412 × 10^(3-23)

E = 69.412 × 10^-20

E = 6.9412 × 10^-19J

6.9412 × 10^-19J is required to break one mole of N=N bond.

Based on the workings above, the photon, which has an energy of 6.1 × 10^-19J is not sufficient to break a N=N bond that has an energy of 6.9412 × 10^-19J

Answer:

Batteries hold chemical energy

Explanation:

The battery acid in a battery leads to chemical energy.

Explanation:

After calculating the density of the material we can tell if the object will sink or float without placing it in water by comparing their density.

This way, comparing the density values of both substances can tell us whether they will float or sink.

Answer:

Gas to Solid

Explanation:

A condensation reaction goes from gas to solid

Condensation is a physical change which alters the physical properties of matter particularly the form and state. In a condensation reaction, a gas goes from solid to liquid.

It is the inverse of the sublimation reaction.

Answer:

See explanation below (Brainlist please)

Explanation:

First of all, we need to understand what is an acidic hydrogen.

An acidic hydrogen, is the atom of hydrogen which is more propense to undergo an acid base reaction, and form a stable ion or molecule in the process.

In other words, is the hydrogen that is more vulnerable to get substracted in an acid base reaction to form another compound.

Knowing this information, gives us an idea of how a molecule can be formed and which kind of compound is formed.

Now, in this question, we have 5 molecules. Each of them is either a ketone or aldehyde, so this mean that we have the carbonile group (C = O), which means that is easier to identify the acidic hydrogen. This is because the Carbonile group is an attractor group, so, it will attract the charges by inductive effect (in some cases by resonance), and the molecule is more stable.

This can be shown by drawing the enolate ion that is formed once the molecule undergo the acid base reaction. As it's an enolate form that we are looking for, then it means that the ketone or aldehyde is undergoing an electrofilic attack with a base. This base will substract the most acidic hydrogen to form a better and stable enolate. The acidic hydrogen and the enolate form can be seen in the attached picture.

a) In the case of acetaldehyde, the most acidic will be the hydrogen of carbon 2, because the hydrogen from the carbonile, once it's substracted, the charge of the carbon cannot be stabilized by resonance. Carbon 2 hydrogens, can do this job easily.

b) Propanal happens something similar to acetaldehyde, the terminal hydrogen cannot be substracted, and carbon 3, once the hydrogen is gone, the negative charge cannot be stabilized by resonance, so hydrogens of carbon 2 can do this.

c) in the case of acetone, is easier to look because we only have the C = O between two methyl group, so you can use either carbon 1 or 3 to do the job.

d) 4 heptanone the most acidic hydrogen would be carbon 3 or 5, because they are closer to the C=O and the ion can be stabilized by resonance.

e) Finally in ciclopentanone, the most acidic hydrogen would be carbon 2 or 5.

See picture for a better understanding.

Hope it helps.

Answer:

3 mol H2/2 mol N2

Explanation:

Mole ratios are basically from the numbers/coefficients in front of the element

Answer: A. It is made of polar molecules.

Explanation:

A polar molecule refers to a molecule that has a covalent bond but has an uneven distribution of electrons due to an atom in the molecule having strong electronegativity which will attract more of the electrons from the other atom.

Water is such a molecule because Oxygen has strong electronegativity which leads to electrons being pulled to it.

Answer:

e

Explanation:

Answer:

Mass, temperature, and phase.

Answer:

B, 2NO + O2 --> 2NO2

Explanation:

The exponents in the rate law for an elementary step are equal to the stoichiometric coefficients of the particles in the equation for the elementary step. Therefore, the elementary reaction must be between two NO molecules and one O2 molecule.

The elementary reaction of the three-body molecular collision is 2NO + O2 -----> 2NO2

The rate of reaction refers to how fast or slow a reaction occurs. The rate equation for an elementary reaction involves the concentration of the species raised to the power of their respective molar coefficients.

We are told that the rate law of the reaction is given as; Rate = k[NO]^2 [O2]. This implies that the single elementary step that is a three-body molecular collision, is represented by the equation; 2NO + O2 -----> 2NO2.

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Answer:

These people painted mostly animals that they most likely hunted as a major source of food, and in doing so left behind evidence of their activities i think

Explanation:

Answer:

Explanation:

Dry I can't c it

Answer:

No

Explanation:

i honestly don't know

Answer: C.

Explanation: Please mark Brainlest Pleasee