PLZ HELP!!

A _____ might be thought of as an inclined plane that moves.

wheel and axle

pulley

wedge

lever

Since it has a 4 protons and 5 neutrons, it has a mass number of 9. The number of electrons is irrelevant for this question. Atomic number is the number of protons, so it is 4. So it is Beryllium

Answer:

Is your answer right or are you asking a question??

Final answer:

The photoelectric effect is indeed fundamental to how solar energy panels operate by using the energy of sunlight to eject electrons in a photovoltaic cell, creating electrical current that can be used as power. True

Explanation:

The photoelectric effect is indeed the basis for how solar energy panels, also known as photovoltaic cells, work today. When photons from sunlight strike the surface of a solar cell, they may have sufficient energy to eject electrons from the material of the cell, typically a semiconductor like silicon. This creates free electrons and corresponding holes. If there is an electrical circuit connected, these free electrons will flow through the circuit, thereby generating an electric current. This electric current can then be harnessed and used to power electrical devices or feed into the electrical grid.

It's important to note that the exact mechanism in solar cells is a bit different from the classic photoelectric effect observed in metals because semiconductors have a band gap that must be overcome by the incoming photons. This process is often referred to as the photovoltaic effect, which is closely related to the photoelectric effect as described by Albert Einstein.

An imbalanced chemical equation describes the products and reactants of a chemical reaction.  Therefore, the balanced equation is 2Fe(HCO[tex]_3[/tex])[tex]_3[/tex]+ 3CaO →Fe[tex]_2[/tex]O[tex]_3[/tex]+3Ca(HCO[tex]_3[/tex])[tex]_2[/tex].

A balanced equation is indeed a chemical reaction equation in which the overall charge and the amount of atoms for every element inside the reaction are the same for both the products and the reactants. In other terms, the mass as well as charge on the both sides of both the reaction are balanced.

An imbalanced chemical equation describes the products and reactants of a chemical reaction yet does not include the quantities needed to meet mass conservation.

Fe(HCO[tex]_3[/tex])[tex]_3[/tex]+ CaO →Fe[tex]_2[/tex]O[tex]_3[/tex]+Ca(HCO[tex]_3[/tex])[tex]_2[/tex]

The atom of Fe on reactant side is 1 while on product side it is 2

2Fe(HCO[tex]_3[/tex])[tex]_3[/tex]+ 3CaO →Fe[tex]_2[/tex]O[tex]_3[/tex]+3Ca(HCO[tex]_3[/tex])[tex]_2[/tex]

Therefore, the balanced equation is 2Fe(HCO[tex]_3[/tex])[tex]_3[/tex]+ 3CaO →Fe[tex]_2[/tex]O[tex]_3[/tex]+3Ca(HCO[tex]_3[/tex])[tex]_2[/tex].

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add them all together then divide it by the amount that Is their

The molarity of chloride ions in the final solution is equal to 0.156 M.

Molarity can be defined as the concentration of the solution in terms of moles of solute and volume of solution in liters.

Given the solution of calcium chloride:

[tex]CaCl_2 \longrightarrow Ca^{2+} + 2Cl^{-}[/tex]

Given the molarity of calcium chloride  = 0.1 M

The concentration of chloride ions in the solution = 2×0.1 = 0.2 M

The volume of solution, V = 50 ml = 0.05 L

The number of moles of chloride = 0.2× 0.05 = 0.001 mol

Amount of NaCl added in the solution = 0.400 g

The number of moles of chloride from NaCl = 0.4/58.5 = 0.0068 mol

Total number of moles of chloride ions = 0.001 + 0.0068 = 0.0078 mol

Volume of the whole solution = 50 ml = 0.05 L

The molarity of the chloride ions in the final solution:

M = 0.0078/0.05

Molarity = 0.156 M

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To form 14.6 grams of iron(iii) oxide, or rust, about 4.4 grams of oxygen are required, based on the stoichiometry of the rust-forming reaction.

The formation of rust, or iron(iii) oxide, involves the reaction of iron with oxygen. To determine the amount of oxygen needed for this process, we need to understand the stoichiometry of the reaction. Two moles of iron react with one mole of oxygen to produce two moles of iron(iii) oxide. The molar mass of iron (Fe) is approximately 56 g/mol, of oxygen (O) is about 16 g/mol, and Iron(III) Oxide (Fe2O3) is ~160 g/mol.

To calculate the grams of oxygen needed for 14.6 g of rust (Fe2O3), you first convert the given mass of iron(iii) oxide into moles, then use the stoichiometry of the reaction to determine how many moles of oxygen are required.

14.6g Fe2O3 * (1 mol Fe2O3/160 g) = 0.09125 mol Fe2O3

The reaction indicates that for every 1 mole of Fe2O3 produced, 1.5 moles of oxygen(O2) are needed. So:

0.09125 mol Fe2O3 * (1.5 mol O2/1 mol Fe2O3) = 0.137 mol O2

Finally, convert moles of oxygen into grams:

0.137 mol O2 * (32 g/mol) = approximately 4.4 grams

So, for 14.6g of Fe2O3 to form, around 4.4 g of O2 are needed.

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To produce 14.6 g of iron(III) oxide, approximately 4.39 grams of oxygen are needed. The nearest answer is option b. 4.4 g

The calculation involves converting grams to moles, using the stoichiometric ratio from the balanced equation, and then converting back to grams.

To determine how many grams of oxygen are needed for the reaction, we start with the balanced chemical equation for the formation of iron(III) oxide (rust):

We know that 14.6 g of Fe₂O₃ is produced.

The molar mass of Fe₂O₃ is calculated as follows:

Next, we convert 14.6 g of Fe₂O₃ into moles:

According to the balanced equation, 2 moles of Fe₂O₃ are produced from 3 moles of O₂. Thus, the moles of O₂ needed are:

Finally, we convert moles of O₂ to grams of O₂ using the molar mass of O₂ (32.00 g/mol):

Therefore, approximately 4.39 grams of oxygen are needed to produce 14.6 g of iron(III) oxide.

Correct question is: Consider the reaction 2Fe(s) + 30₂ (g) ► Fe₂O₃(g) . If 14.6 g of iron(III) oxide (rust) is produced from a certain amount of iron, how many grams of oxygen are needed for this reaction?

a. 1.85 g

b. 4.4 g

c. 3.74 g

d. 2.68 g

Answer:

It's the metal that gets named first.

Explanation:

Compounds are named based on the ions they produced on dissolution. In a compound that contains monatomic ions, the metallic ion is a named first. Thus 4th option is correct.

A monatomic ion is a single atom possessing a positive charge or negative charge. The ion bearing a positive charge is called cation and the ion bearing negative charge is called anion.

Cations are formed by the losing or donation of electrons. Whereas, anions are formed by withdrawal of electrons. For example Na+ is a cation and Cl- is an anion formed by losing of one electron from sodium metal and accepting an electron Cl gas respectively.

These single atomic  cation and anions together forms ionic compounds called monatomic ions. For example NaCl containing sodium ion and chloride Cl- ion is a monatomic ion and its name is started with the metal sodium namely sodium chloride.

Similarly HBr containing H + ion and Br- ion have the name hydrogen bromide. Therefore, the metal named first for a compound containing monatomic ions.

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The wavelength of a wave can be calculated by using the formula λ = v/f, where v is the wave's speed and f is its frequency. Without knowing the type of wave or its speed, we cannot find the specific wavelength for a wave with a frequency of 4.89 Hz. If it's a sound wave in air, the wavelength would be approximately 70.14 m.

To calculate the wavelength of a wave with a given frequency, we use the formula for wave speed: v = fλ, where v is the speed of the wave, f is the frequency, and λ(lambda) is the wavelength. Typically, the speed of a sound wave in air is about 343 m/s. However, the question does not specify the type of wave or its speed, so we cannot make this assumption without more information. In general, with the speed of the wave and its frequency, we could re-arrange the formula to find the wavelength: λ = v/f.

Therefore, if the type of wave and its speed were known, you could substitute the given frequency and the known speed into the formula to find the wavelength. For instance, if you know that you're working with a sound wave travelling through air at room temperature (v approximately equal to 343 m/s), you could calculate the wavelength as follows: λ = v/f = 343 m/s / 4.89 Hz = approximately 70.14 m.

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Answer:

Where is. Best of information

Explanation:

Answer : When an electron is lost then the atomic radius is, decreases.

Explanation :

Atomic radius of an atom is defined as the total distance from the nucleus to the valence shell of the atom.

As moving from left to right in a period, more electrons are added in the same shell and the attraction between the last electron and nucleus increases, which results in the shrinkage of size of an atom.

Thus, atomic radii from the left to right across a period tend to decrease.

As moving from top to bottom in a group, there is an addition of shell around the nucleus and the outermost shell gets far away from the nucleus and hence, the distance between the nucleus and outermost shell increases.

Thus, atomic radii from the top to bottom in a group tend to increases.

When atom loses an electron then it becomes positively charged and the atomic radius of positively charged ion is lower than neutral atom.

When atom gains an electron then it becomes negatively charged and the atomic radius of negatively charged ion is more than neutral atom.

Hence, when an electron is lost then the atomic radius is, decreases.

Answer:The density of the moon rock is [tex]3.3398 g/cm^3[/tex].

Explanation:

Mass of the  moon rock = 5.761 kg = 5671 g

(1 kg = 1000 g)

Volume of the moon rock = [tex]1,698 cm^3[/tex]

[tex]Density=\frac{Mass}{Volume}=\frac{5761 g}{1,698 cm^3}=3.3398 g/cm^3[/tex]

The density of the moon rock is [tex]3.3398 g/cm^3[/tex].

Final answer:

A lamp with an incandescent bulb is less efficient as it converts more electrical energy to heat, whereas a TV uses energy more effectively for display and sound. Employing more efficient lighting such as fluorescent or LED bulbs can significantly reduce energy usage and costs.

Explanation:

Differences in Electrical Energy Use Between Lamps and TVs

When comparing the use of electrical energy between different appliances such as a lamp and a TV, it is important to consider their power consumption and efficiency. A lamp, especially if it uses an incandescent bulb, tends to be less efficient as it loses most of its energy as heat rather than light. On the other hand, a TV is designed to convert electrical energy into both light (the visual part of the display) and sound, typically using the energy more efficiently regarding the provision of its intended service.

To reduce electrical energy consumption and its associated costs, one can switch from incandescent bulbs to fluorescent lights or LED lights, which are more efficient. Fluorescent lights are about four times more efficient than incandescent lights, and LEDs are even more efficient than CFLs. Considering that a significant percentage of energy use in homes and businesses goes to lighting, switching to more efficient lighting options presents a valuable opportunity for energy and cost-saving.

For example, one could replace a 60-W incandescent bulb with a 15-W CFL that provides the same brightness and color. This change not only reduces power consumption but also lowers heat transfer and environmental impact since CFLs have a longer lifespan. LED lights offer improvements over CFLs in both efficiency and lifespan, but their higher cost might be a barrier, although prices have been decreasing over time.

Isomers can be separated through distillation because they often have distinct boiling points. Distillation processes, like simple and fractional distillation, leverage these differences to achieve separation, applying this principle widely in industrial applications.

The question posed, why can you separate isomers through distillation, revolves around the foundational principles of physical chemistry and the separation of mixtures. Distillation is a technique that separates components of a mixture based on differences in their boiling points. Isomers, being different structural or spatial arrangements of the same molecular formula, can often have differing boiling points. This variance allows for the separation of isomers through distillation processes, such as simple distillation or fractional distillation.

Simple distillation is effective when the boiling points of the substances in the mixture have a wide gap (more than 150°C apart), primarily separating a more volatile substance from a less volatile one. Fractional distillation, on the other hand, is used for substances whose boiling points are closer together and relies on a fractionating column packed with material that provides a large surface area for multiple cycles of vaporization and condensation. This repeated process allows for finer separation of components, making it ideal for separating isomers with somewhat similar boiling points.

Distinct boiling points of isomers, hence, are the key reason why distillation can be used as a method of separation. This principle is widely applied in industries, for example, in the refining of crude petroleum or the production of alcoholic spirits, where the separation of components based on their boiling points is crucial.

C) just took test please make brainiliest

Different continents had different rock types supports Wegener's theory of continental drift. Therefore, option (A) is correct.

According to Wegener’s Continental Drift theory, all the continents were united as one single continental mass named a Super Continent, and Pangaea and a Mega Ocean surrounded this supercontinent.

The similarity in geological formations of the southern continent had led Roberto Mantovani that all the continents had once been joined into a supercontinent. Then Wegener noted the similarity between Mantovani's and his own maps of the previous positions of the southern continents.

In Mantovani's conjecture, the continent split due to volcanic activity led by thermal expansion, and the newly formed continents drifted away from each other due to further expansion of the rip zones, where the oceans presently lie.

The continents were separated by the centrifugal pseudo force of the rotation of the earth but calculations showed that the force was not sufficient.

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Sand was separated from the mixture using a filter because it is not soluble in water, making it a suitable method for separating insoluble solids from liquids.

Based on the provided information, let's analyze how the mixture of sand was separated and which physical property was used for the separation:

Mixture: Sand

How did you separate it?

Separated using a filter; not soluble in water.

Which physical property did you use to separate it?

The physical property used to separate sand from the mixture was "not soluble in water."

Here's the explanation:

Separated using a filter: This separation method suggests that sand was separated from the mixture by passing the mixture through a filter. The filter allows the liquid components of the mixture (if any) to pass through while retaining the solid sand particles.

Not soluble in water: This property indicates that sand doesn't dissolve in water. Since it doesn't dissolve, it remains as solid particles when mixed with water, allowing it to be separated by filtration.

So, the method used to separate the sand from the mixture was filtration, and the physical property applied was that sand is not soluble in water. This combination of properties makes it possible to separate sand from the mixture efficiently.

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The mass of water was determined by subtracting the mass of anhydrous NaC2H3O2 from the hydrated sample. The moles of each component were calculated based on their molar masses, and the ratio of moles of water to moles of NaC2H3O2 was found to be approximately 3:1.

To determine the ratio of moles of water to moles of NaC2H3O2 in the original hydrated compound, we first need to find the mass of the water that was in the sample. We subtract the mass of the anhydrous NaC2H3O2 from the original mass of the hydrated sample:

Mass of water = 3.677g (original mass) - 2.216g (anhydrous NaC2H3O2) = 1.461g

Next, we calculate the moles of NaC2H3O2 using its molar mass (82.03 g/mol):

Moles of NaC2H3O2 = 2.216g / 82.03 g/mol ≈ 0.0270 moles

We do the same for the water using its molar mass (18.02 g/mol):

Moles of water = 1.461g / 18.02 g/mol ≈ 0.0810 moles

Finally, we find the ratio of moles of water to moles of NaC2H3O2:

Ratio = Moles of water / Moles of NaC2H3O2 ≈ 0.0810 moles / 0.0270 moles ≈ 3

Therefore, the ratio of moles of water to moles of NaC2H3O2 in the original compound is approximately 3:1.

Distance is the measurement that defines the length of the points covered by the object. The chemistry lab is 1113.51706 feet from the nurse's office.

Distance is said to be the measurement that defines how far an object has moved from its initial point at the given time. It is an interval and span between the two defined points.

In physics, distance is estimated and measured in kilometers, meters, centimeters, inches, feet, miles, and yards. They are units of length as the distance is said to be the length between two points.

It has been known that one kilometer contains 3280.84 feet.

Given,

Distance between chemistry lab and nurse office = 0.3394 km

Converting the values from km to feet as:

1 km = 3280.84 feet

0.3394 km = 0.3394 km × 3280.84 feet

= 1113.51706 feet

Therefore, the distance is 1113.51706 feet.

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To determine the grams of H2 gas produced from the given mass of Al, we use stoichiometry and the molar mass of H2.

To determine the number of grams of H2 gas that can be produced, we need to use the given information about the mass of Al and the balanced chemical equation.

First, we calculate the number of moles of Al by dividing the mass of Al by its molar mass. Then we use the stoichiometric ratio from the balanced equation to find the moles of H2 gas produced. Finally, we convert moles of H2 gas to grams using the molar mass of H2.

By following these steps, we can calculate the grams of H2 gas produced from the given mass of Al.

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By reacting 63.0 grams of Al with excess hydrochloric acid, approximately 7.07 grams of H₂ gas will be produced.

This is based on stoichiometric calculations using a balanced chemical equation.

Given that we have 63.0 grams of Al, we start by converting this mass to moles:

Step 1: Calculate moles of Al

Step 2: Use the mole ratio to find moles of H₂ produced

Step 3: Convert moles of H₂ to grams

Therefore, 6.99 grams of H₂ gas can be produced by reacting 7.07 grams of Al with an excess of dilute hydrochloric acid.

Correct question is: How many grams of H₂ gas can be produced by the reaction of 63.0 grams of Al(s) with an excess of dilute hydrochloric acid in the reaction shown below?

2 Al(s) + 6 HCl(aq) → 2 AlCl₃(aq) + 3 H₂(g)

Cr and O are most likely to be part of a polyatomic ion.

Cr belongs to the transition metal series in the periodic table and has vacant d-orbitals. As a result it can exist in more than one oxidation state, the most common being +6, +3 and +2. Oxygen exists in -2 oxidation state. Hence, Cr and O can combine to form different polyatomic ions like: CrO₄²⁻ and Cr₂O₇²⁻ (Cr in +6 state)

K, Li and Mg exist in only one oxidation state +1 (K and Li) and +2(Mg). F and Br exhibit an oxidation state of -1. Therefore, they are not likely to form polyatomic ions.

Ans (a) Cr and O

4.02 atm

Given:  

SO₂ (5.00 g) and CO₂ (5.00 g) were placed in a 750.0 ml container at 50.0°C.

Question:  

The partial pressure of CO₂ in the container was ... atm.

The Process:

This problem is only required to find the partial pressure of CO₂ in containers, so we ignore SO₂ in the calculation.

Step-1: preparing for the molar mass of carbon dioxide

Mr CO₂ = 12 + 2(16) = 44 g/mol

Step-2: find out the number of mole of CO₂

Mole conversions [tex]\boxed{ \ moles = \frac{mass}{Mr} \ }[/tex]

Therefore, moles of CO₂ = [tex]\boxed{ \ moles = 5.00 \ g \times \frac{1 \ mol}{44 \ g} \ } \rightarrow \boxed{ \ = 0.11364 \ moles \ }[/tex]

Step-3: find out the partial pressure of CO₂ (in atm)

We use an equation of state for an ideal gas:  

[tex]\boxed{\boxed{ \ \frac{pV}{T} = nRT \ }}[/tex]  

Prepare p as the subject you want to find.

[tex]\boxed{ \ p = \frac{nRT}{V} \ }[/tex]

[tex]\boxed{ \ p = \frac{0.11364 \times 0.0821 \times 323}{0.75} \ }[/tex]

Thus the partial pressure of CO₂ in the container was 4.018 atm, rounded up to 3 significant digits, we get 4.02 atm.

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