Calculate the wavelength of light (in nm) of the spectral line of Hydrogen where an electron falls from the 6th Bohr orbit to the 3rd Bohr orbit.

a) 540 nm
b) 2000 nm
c) 1090 nm
d) 1050 nm

Answer:

4.03 moles

Explanation:

We know that the molar mass of Carbon is 12.011, thus we can solve for moles by dividing the grams given by the molar mass.

48.4 g / 12.011 g = 4.03 moles

Answer:

Option B is correct.

4

Explanation:

We know that an atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.

All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example, if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.

In given problem we are given with 2 neutrons of helium. We know that the atomic number of He is 2. Thus Mass number of He is,

Number of neutrons + number of proton

2 + 2 = 4

Thus, option B is correct.

Answer:Ithink erosion cuz if we can tell how long ago it eroded we can see how old it is

Explanation:

Answer:

refer to below

Explanation:

- read your textbook! especially the topics that are most confusing

- as you read, make sure to take notes/make an outline. write the words from the text in your own words. In chem, the textbook explanations are usually very detailed, so putting it in your own words will help you remember and understand what you write.

- make sure you really understand the concepts. don't just memorize what you read.

- draw diagrams and structures. seeing how things are structured will help you visualize what you learn

- ask questions to your teacher. if there is anything confusing, make sure to refer to your teacher as they will hopefully be able to explain it so  it won't be confusing

These tips have helped me pass chem with an A. Hope all of this helped!

Answer:

Explanation:

Study material, ask for help, read textbook and do practice problems, get a tutor, beg your teacher for marks,

The minimum entropy change of the heat-supplying source is -0.87 kJ/K.

In this case, given the initial conditions, we first use the 10-% quality to compute the initial entropy.

S₁ = 1.485  +  (0.1)(5.6865) = 2.0537 kJ/kg K

The entropy at the final state given the new 40-% quality:

S₂ = 1.4337  +  (0.4)(5.7894) = 3.7495 kJ/kg K

m₁ = 0.026/(0.001057   +  0.1 x 1.002643) = 0.257 kg

m₂ = 0.026/(0.001053   +  0.4 x 1.158347)  = 0.056 kg

ΔS + S₁  - S₂  + S₂m₂  - S₁m₁  -  sfg(m₂  -  m₁)  > 0

ΔS + 2.0537 -  3.7495 + (3.7495 x 0.056)  -   (2.0537 x 0.257)  - 5.6865( 0.056 - 0.257)  >  0

ΔS > -0.87 kJ/K

Thus, the minimum entropy change of the heat-supplying source is -0.87 kJ/K.

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Nadia will take 8 seconds to reach her friend's house.

Speed is the measure of the distance traveled by an object per unit of time. It is a scalar quantity and is typically expressed in units such as meters per second (m/s), miles per hour (mph), or kilometers per hour (km/h).

To calculate the time Nadia will take to reach her friend's house, we can use the formula;

time = distance / speed

where distance is the amount of space traveled by an object, and time is the duration of travel.

Put the values given in the problem, we have:

time = 24 meters / 3 m/s

time = 8 seconds

Therefore, Nadia will take 8 seconds.

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Answer:

name four agricultural inputs are subsidized by the government

0.297 kJ of heat is needed to raise the temperature of 10g of aluminum from 22 degrees Celsius to 55 degrees Celsius.

The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius.

It is a measure of how much energy it takes to raise the temperature of a substance. It is the amount of heat necessary to raise one mass unit of that substance by one temperature unit.

It is given by the formula -

                                                  Q = mcΔT

where, Q = amount of heat

m = mass

c = specific heat

ΔT = Change in temperature

Given,

mass = 10g

c = 0.901J/g⁰C

Initial temperature (T₁) = 22⁰C

Final Temperature (T₂) = 55⁰C

Q = mcΔT

= 10 × 0.901 × (55 -22)

= 297.33 J = 0.297 kJ

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The total number of atoms in 3.75 mol of ammonium nitrate, NH4NO3, is equal to the Avogadro's number, which is 6.022 x 10^23, times the number of moles, which is 3.75 in this case.

Thus, the total number of atoms in 3.75 mol of ammonium nitrate is equal to 2.26 x 10^24 atoms.

This number can be further broken down into the number of atoms of each element present in the compound. Ammonium nitrate is composed of two elements, nitrogen (N) and hydrogen (H). For each mole of ammonium nitrate, there are 4 moles of hydrogen atoms and 2 moles of nitrogen atoms.

Therefore, in 3.75 moles of ammonium nitrate, there are 15 moles of hydrogen atoms and 7.5 moles of nitrogen atoms, which is equal to 9 x 10^24 hydrogen atoms and 4.05 x 10^24 nitrogen atoms.

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Answer:

Acids and bases can help neutralize each other.

Acids turn litmus paper red, bases turn it blue.

Strong bases can be slippery and slimy feeling.

Acids taste sour, bases taste bitter.

Proteins are made up of amino acids.

Vitamin C is also an acid called ascorbic acid.

Ammonia is a base chemical.

Explanation:

school

I just did this for my class.

Here are 10 facts about acids and bases to help you learn about acids, bases, and pH along with a chart for comparison.

1. Any aqueous (water-based) liquid can be classified as an acid, base, or neutral. Oils and other non-aqueous liquids are not acids or bases.

2. There are different definitions of acids and bases, but acids can accept an electron pair or donate a hydrogen ion or a proton in a chemical reaction, while bases can donate an electron pair or accept hydrogen or a proton.

3. Acids and bases are characterized as strong or weak. A strong acid or strong base completely dissociates into its ions in water. If the compound does not completely dissociate, it's a weak acid or base. How corrosive acid or a base does not relate to its strength.

4. The pH scale is a measure of the acidity or alkalinity (basicity) or a solution. The scale runs from 0 to 14, with acids having a pH less than 7, 7 being neutral, and bases having a pH higher than 7.

5. Acids and bases react with each other in what is called a neutralization reaction. The reaction produces salt and water and leaves the solution closer to a neutral pH than before.

6. One common test of whether an unknown is an acid or a base is to wet litmus paper with it. Litmus paper is a paper treated with an extract from a certain lichen that changes color according to pH. Acids turn litmus paper red, while bases turn litmus paper blue. A neutral chemical won't change the paper's color.

7. Because they separate into ions in water, both acids and bases conduct electricity.

8. While you can't tell whether a solution is an acid or a base by looking at it, taste and touch may be used to tell them apart. However, since both acids and bases can be corrosive, you shouldn't test chemicals by tasting or touching them! You can get a chemical burn from both acids and bases. Acids tend to taste sour and feel drying or astringent, while bases taste bitter and feel slippery or soapy. Examples of household acids and bases you can test are vinegar (weak acetic acid) and baking soda solution (diluted sodium bicarbonate -- a base).

9. Acids and bases are important in the human body. For example, the stomach secretes hydrochloric acid, HCl, to digest food. The pancreas secretes a fluid rich in the base bicarbonate to neutralize stomach acid before it reaches the small intestine.

10. Acids and bases react with metals. Acids release hydrogen gas when reacted with metals. Sometimes hydrogen gas is released when a base reacts with a metal, such as reacting sodium hydroxide (NaOH) and zinc. Another typical reaction between a base and a metal is a double displacement reaction, which may produce a precipitate metal hydroxide.

Answer:

What? i think its an incomplete question

Explanation:

The decomposition of aspirin (acetylsalicylic acid,\(C_{9} H_{8} O_{4}\)) can occur through the hydrolysis reaction, resulting in the formation of acetic acid (\(CH_{3} COOH\)) and salicylic acid (\(C_{7} H_{6}O_{3}\)).

The decomposition of aspirin (acetylsalicylic acid, \(C_{9} H_{8} O_{4}\)) can occur through the hydrolysis reaction, resulting in the formation of acetic acid (\(CH_{3} COOH\)) and salicylic acid (\(C_{7} H_{6}O_{3}\)). To determine the moles of each product formed, we need to consider the balanced chemical equation for the reaction:

\(C_{9} H_{8} O_{4} = > C_{7} H_{6}O_{3} +CH_{3} COOH\)

From the equation, we can see that for every 1 mole of aspirin, 1 mole of salicylic acid and 1 mole of acetic acid are produced.

Therefore, the moles of salicylic acid and acetic acid formed will be equal to the number of moles of aspirin that decomposes. If we know the amount of aspirin in moles, we can directly calculate the moles of each product based on stoichiometry.

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Answer:

can you give more information on the work a planet with radius 10 times of the Saturn was discovered late last week isn't enough information

Answer:

i think plumber

Sodium hydroxide is generally referred to as caustic soda used in soaps and cleaners. A plumber would most likely be required to work with sodium hydroxide. Hence, option A is correct.

Soaps, paper, explosives, dyes, and petroleum are all made with sodium hydroxide. The presence of sodium hydroxide in a cleanser or a homemade aqueous solution converts these disconcerting fats into soaps, which are easily removed by water.

They have no odor and no color making them react with water and strong acids to produce salts. They are considered ionic compounds with sodium cation and chloride anion. They also are used in oxide coating and cleaning of metals.

Therefore, option A. plumber will most likely use sodium hydroxide.

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Approximately 4.37 x 10^23 molecules of HCl would be required to form 34.52 g of MgCl₂.

To determine the number of molecules of HCl required to form 34.52 g of MgCl₂, we need to use the molar mass and stoichiometry of the balanced equation:

Mg(OH)₂(s) + 2 HCl(aq) → 2 H₂O(l) + MgCl₂(aq)

The molar mass of MgCl₂ is 95.21 g/mol.

First, we need to calculate the number of moles of MgCl₂ formed:

Moles of MgCl₂ = mass of MgCl₂ / molar mass of MgCl₂

Moles of MgCl₂ = 34.52 g / 95.21 g/mol

Moles of MgCl₂ = 0.363 mol

According to the balanced equation, the stoichiometric ratio between HCl and MgCl₂ is 2:1. Therefore, the moles of HCl required can be calculated as follows:

Moles of HCl = 2 * Moles of MgCl₂

Moles of HCl = 2 * 0.363 mol

Moles of HCl = 0.726 mol

To calculate the number of molecules, we need to use Avogadro's number, which is approximately 6.022 x 10^23 molecules/mol.

Number of molecules of HCl = Moles of HCl * Avogadro's number

Number of molecules of HCl = 0.726 mol * 6.022 x 10^23 molecules/mol

Number of molecules of HCl = 4.37 x 10^23 molecules

Therefore, approximately 4.37 x 10^23 molecules of HCl would be required to form 34.52 g of MgCl₂.

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Answer:

Its is C urea if this is correct please make me brainliest

The statement is correct. The photoelectric effect refers to the phenomenon where electrons are ejected from the surface of a material when it is exposed to light. The frequency of light striking an electron in a metal must be above the threshold frequency in order for the photoelectric effect to occur.

The statement is correct. The photoelectric effect refers to the phenomenon where electrons are ejected from the surface of a material when it is exposed to light. However, for the photoelectric effect to occur, the frequency of the incident light must be above a certain threshold frequency.

The threshold frequency is the minimum frequency of light required to dislodge electrons from the material. Below this threshold frequency, regardless of the intensity or duration of the light, no electrons will be emitted.

This behavior can be explained by the particle-like nature of light, where light is composed of discrete packets of energy called photons. The energy of a photon is directly proportional to its frequency. Only photons with energy greater than or equal to the binding energy of the electrons in the material can dislodge them.

Therefore, the frequency of light striking an electron in a metal must be above the threshold frequency in order for the photoelectric effect to occur.

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Answer:

a.is the correct answer

Answer:

1. Percentage yield = 57.2%

2. Percentage error = 74.9%

Explanation:

From the question given above, the following data were obtained:

Actual yield = 5.06 g

Experimental yield = 8.85 g

Percentage yield =?

Percentage error =?

1. Determination of the percentage yield.

Actual yield = 5.06 g

Experimental yield = 8.85 g

Percentage yield =?

Percentage yield = Actual yield /Experimental yield × 100

Percentage yield = 5.06 / 8.85 × 100

Percentage yield = 57.2%

2. Determination of the Percentage error.

Actual yield = 5.06 g

Experimental yield = 8.85 g

Percentage error =?

Percentage error = |Experimental – Actual| / Actual yield × 100

Percentage error = |8.85 – 5.06| / 5.06 × 100

Percentage error = 3.79 / 5.06 × 100

Percentage error = 74.9%

Answer:

Gravity

Explanation:

Gravity is a field and a force that makes two objects attract to each other.

Answer:

The answer is B(scale)

Explanation:

Since the question asked about a range, the scale would be the most logical answer since scales are used to measure.

Answer:

the answer is C.

Explanation:

Answer:

heres your answer

To determine whether a bond is Covalent or Ionic, you must know the difference in electronegativity (a fancy word for describing how good a job a particular element does at attracting new electrons).

Explanation:

The rate law and the rate law constant for the following reaction: bro3 5br 6h -> 3br2 3h2o is 1.5 × 10-3 M/S.

This means that the molecularity and order of the reaction with regard to [Br] are 5 and 1, respectively. The rate of bromine emergence is related to the rate of bromide ion evaporation in the reaction "BrO 3(-)(aq) + 5Br(-) + 6H(+) rarr 3Br 2 + 3H 2O." The reaction rate for the reaction A->B is increased by 8 times when the concentration of both reactants is doubled, while the reaction rate is only doubled when the concentration of B is doubled. If there are solely saturated chemicals present, it turns reddish-brown. By gradually adding bromine solution until the first reddish-brown hue appears, you may gauge how unsaturated a compound is. The unsaturation increases as more bromine solution is needed.

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Approximately 766.08 grams of oxygen are required to completely react with 240g of C₂H₆.

To determine the amount of oxygen required to completely react with 240g of C₂H₆ (ethane), we need to set up a balanced chemical equation for the combustion of ethane.

The balanced equation for the combustion of ethane is as follows:

C₂H₆ + O₂ → CO₂ + H₂O

From the balanced equation, we can see that the stoichiometric ratio between C₂H₆ and O₂ is 1:3. This means that for every one mole of C₂H₆, three moles of O₂ are required for complete combustion.

To calculate the amount of oxygen required, we need to convert the given mass of C₂H₆ to moles using its molar mass, and then use the stoichiometric ratio to determine the moles of O₂ required. Finally, we can convert the moles of O₂ back to grams using the molar mass of oxygen.

The molar mass of C₂H₆ is calculated as follows:

(2 x atomic mass of carbon) + (6 x atomic mass of hydrogen)

(2 x 12.01 g/mol) + (6 x 1.01 g/mol) = 30.07 g/mol

Now, we can proceed with the calculation:

Calculate the moles of C₂H₆:

moles of C₂H₆ = mass of C₂H₆ / molar mass of C₂H₆

moles of C₂H₆ = 240 g / 30.07 g/mol ≈ 7.98 mol

Determine the moles of O₂ using the stoichiometric ratio:

moles of O₂ = moles of C₂H₆ x (3 moles of O₂ / 1 mole of C₂H₆)

moles of O₂ = 7.98 mol x 3 ≈ 23.94 mol

Convert moles of O₂ to grams:

mass of O₂ = moles of O₂ x molar mass of O₂

mass of O₂ = 23.94 mol x 32.00 g/mol = 766.08 g

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Answer:

What is Smoky Quartz?

Smoky quartz is a color-variety of crystalline quartz. It ranges from a light yellowish brown to a brown that is so dark that it appears to be black. Less-desirable specimens have a grayish brown color. When cut as a gem, stones with an orangish brown to a reddish brown color are preferred by many people.

Smoky quartz is a relatively inexpensive gem material because it is abundant, found in many locations, and its brown color is not currently in high demand. It is often found in large crystals of excellent transparency with few inclusions.

The color of smoky quartz is produced when natural radiation, emitted from the surrounding rock, activates color centers around aluminum impurities within the crystalline quartz. Amethyst forms in a similar way, from the activation of color centers around iron impurities.

Explanation:

Treatments

Some specimens of rock crystal can be given the color of smoky quartz by irradiation in a laboratory. The exposure can be controlled to vary the color of the product. This is not often done in a lab because natural smoky quartz is inexpensive and abundant relative to demand. For the same reason, synthetic smoky quartz is seldom produced. Natural smoky quartz with a very dark color is sometimes heated to lighten its color.

faceted smoky quartz

Faceted smoky quartz: Rich brown faceted stones of smoky quartz, all cut from material mined in Brazil. From left to right they are a 5.28 carat pear concave cut measuring 14.84 x 11.01 millimeters; a 7.4 carat round measuring 14.09 millimeters; and a 7.16 carat cushion checkerboard cut measuring 12.19 x 12.15 millimeters.

Uses of Smoky Quartz

Smoky quartz is faceted or cut into beads and cabochons. These gems are often used in rings, pendants, necklaces, earrings, and brooches for people who like the yellowish brown to brown color.

Smoky quartz with a dark brown color is often used in men's rings and cufflinks. During the Victorian Period, dark brown stones from the Mourne Mountains of Ireland were often used in mourning jewelry.

Because smoky quartz has a low price and large pieces are easily obtained, it is a favorite practice material of people who are learning to facet. It is also frequently used as a carving material.

Smoky quartz is a gem that

has an unusual dark brown or black color when it occurs as crystals with an Al impurity in pegmatites rich in silica.

Smoky quartz is a crystalline solid substances that has variety of colors which can range from light yellow to dark brown.

It is normally expensive and it is cut as a rare gem stones which is admired by people and use for buildings, monuments and decorations. It is a stone use for grinding, it has medicinal properties as it help detoxify.

Therefore, Smoky quartz is a gem that

has an unusual dark brown or black color when it occurs as crystals with an Al impurity in pegmatites rich in silica.

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Answer:

The rest of the food molecule is converted to other carbon molecules. The hawk cannot consume all the parts of the squirrel. It will feed as a carnivore on the fleshy part of its prey. The matter is converted to other carbon molecules

Explanation:

Based on the redox equations;

The emf of the cell, E°cell of the cells formed from the half-reactions is 0.21 V

Reducing agents are substances which donates electrons and are oxidized in a redox reaction.

Oxidizing agents are substances which accept electrons and are reduced in a redox reaction.

From the given the redox equations:

a) O_2(g) + NO(g) + H_2O(l) → NO_3^{-}(aq) + H^{+}(aq)

b) CrO_4^{2-}(aq) + H_2O(l) + Cu(s) → Cr(OH)_3(s) + Cu(OH)_2(s) + OH^{-}(aq)

2. The emf of the cell, E°cell = E°red - E°oxi

In the cell, copper is reduced while tin is oxidized.

E°cell = (0.34 - 0.13) V

E°cell = 0.21 V

Therefore, the emf of the cell, E°cell is 0.21 V

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