What is the force that holds a pencil down against a desk?
Responses

friction


momentum

gravity


normal

In the given condition where the thylakoids are isolated from the chloroplasts to make the pH of the thylakoid space acidic, the isolated thylakoid will form the ATP.

ATP is also referred to as Adenosine Triphosphate and is correctly called as the energy currency of the cell as it is responsible molecule for carrying the energy units in the cell. When the isolated thylakoids are made to transfer in the pH = 8 basic solution, then the acidic lumen of the chloroplast will be having a higher concentration of H⁺ ions. When they are placed in the basic solution then the H⁺ ions will move out because of the occurrence of concentration gradient which is higher in the lumen than the surrounding. The chloroplasts will now bear synthesis of ATP. Therefore, the isolated thylakoid is able to make ATP when the lumen is acidic, and the surroundings are made basic in nature.

Thus, the thylakoid which is isolated will bear the synthesis of ATP.

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Because the oldest rocks with fossilized evidence of life on earth are at least 3.5 billion years old, life on earth must have started at least then.

According to a study, Earth may have been a "waterworld" without continents 3 billion years ago. Without any continents to divide the oceans, Earth may have been entirely submerged in water about 3 billion years ago, resembling a "waterworld." The 3.5 billion year old "stromatolites," which are hard structures made by microbes, also contain evidence of their presence. Stromatolites are produced when microbe-made sticky mats trap and organize sediments into layers. Even as the microbes disappear, minerals precipitate inside the layers, forming strong structures.

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The empirical formula of the compound, given it contains 19.3% Na, 26.9% S, and 53.8% O is NaSO₄

The following paameters were obtained from the question:

The empirical formula of the compound can be obtained as follow:

Divide by their molar mass

Na = 19.3 / 23 = 0.839

S = 26.9 / 32 = 0.840

O = 53.8 / 16 = 3.3625

Divide by the smallest

Na = 0.839 / 0.839 = 1

S = 0.840 / 0.839 = 1

O = 3.3625 / 0.839 = 4

Thus, the empirical formula of the compound is NaSO₄

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Complete question:

A compound is 19.3% Na, 26.9% S, and 53.8% O. Its formula mass is 238 g/mol. What is the empirical formula? Show your work in a neat and logical manner.

The balanced chemical equation of combustion of propanol is 2 C₃H₇OH +9 O₂[tex]\rightarrow[/tex] 6 CO₂ +8 H₂O.

Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.

A plus sign is present between reactants and products if they are more than one in any case and an arrow is present pointing towards the product side which indicates the direction of the reaction .There are coefficients present next to the chemical symbols and formulas .

The first chemical equation was put forth by Jean Beguin in 1615.By making use of chemical equations the direction of reaction ,state of reactants and products can be stated. In the chemical equations even the temperature to be maintained and catalyst can be mentioned.

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Answer

b. 4.2 x 10²⁴

Explanation

Given:

Moles of H2O = 7 moles

Avogadro's Number is 6 x 10²³

What to find:

The number of articeles of H2O present in 7 moles of H2O.

Solution:

1 mole f any substanc contains 6 x 10²³ partcicles

Therefore 7 moles of H2O will contain

The correct answer is option:

b. 4.2 x 10²⁴

High silica content lava flow is thick and viscous and does not flow easily.

Though lava rises upwards toward the surface, it is too thick to pass through the Earth's fissures and crevices. Pressure is increasing as the lava continues to surge upward.

The least dangerous process involved in volcanic eruptions is lava flow. The temperature, silica content, extrusion rate, and slope of the terrain are all factors that affect how far a lava flow travels. A lava flow with a high silica content or one that is chilly will not move very far. Such a flow would be extremely viscous (a high resistance to flow). Low silica content is characteristic of basalt flows like those in Hawaii, OR long-distance flow, and low viscosities.

A MAGMA COMPOSITION AND TYPES OF ROCK

There are various varieties of magmas, ranging from mafic magmas, which have high Fe and Mg contents and relatively little silica, to felsic magmas, which have low Fe and Mg contents and relatively high silica.

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Answer:

1 mole of Barium Nitrate has One mole of Barium ions, two moles of Nitrate ions

Using significant figures and rounding up, the resulting mass is 80.5 g.

When using addition or subtraction, the total number of significant figures is relevant. Instead, the last significant figure of every number is considered.

In 30.05, the last significant figure is 5, and it is in the hundredths. In 50.0, the last significant figure is 0, and it is in the tenths. Finally, in 0.4006, the last significant figure is 6, and it is in the ten thousandths. Of the three, the 0 from 50.0 is in the "highest" position, and so the last significant figure of the results should also be in the tenths.

If we add the numbers up, we get:

30.05 g + 50.0 g + 0.4006 = 80.4506 g

Because the last significant figure should be in the tenths, we are going to round up 4 to 5, because trailing numbers are greater than 0, so the final mass will be 80.5 g.

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Among the given options, the derived unit is Newton. Option d is correct.

Derived units are measure units that have been derived from more than one base unit. Also understood as the units derived from the fundamental units. They either lack dimension or are the products of base units, like derived unit of force is Newton. A total of 22 derived units exist. The basic 7 derived units are Length is meter(m), Mass is  kg (kilogram) ,Time is s (second), Electric Current is  A (Ampere) ,Thermodynamic Temperature is  K (degrees Kelvin) ,Amount of Substance is mol (mole) and Luminous Intensity is  cd (candela)

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Answer:

A. 32 g

Explanation:

Density = 2.7 g/cm3

Volume = 2 x 2 x 3 = 12 cm3

Mass = dV = 2.7 x 12 = 32.4 g or 32 g

The answer is 22.98977. We assume you are converting between grams Na and mole.

Answer:

28 g

Explanation:

d = m/V

m = dV = 10.5 x 56.0 = 28 g

The cloud mist as the number of "dry days” increases and fewer precipitation events contributing to the annual total of cloud mist or the dry days has been increased.​

The main procedure of formation of cyclones is that when hot moist air flows at  the upper surface of the ocean it tries to move in upward direction due to which less amount of air is left at the surface of ocean and hence a lower air pressure is created in this area.

Surrounding air which is at higher air pressure try to push the low pressure air which rises the temperature of low pressure air and again this air moves upward leaving behind less air at the surface of the ocean.

When this high temperature and moist air moves in the upward direction it temperature decreases due to which clouds are formed . This combination of clouds and wind continuously grows and started spinning. When this combination of wind and clouds spin fast,  that time an eye is formed at the center. At this center very low air pressure is there and  air with high pressure flows down into this center.

Therefore, The cloud mist as the number of "dry days” increases and fewer precipitation events contributing to the annual total of cloud mist or the dry days has been increased.​

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A. The formula and the name of the oxide is VO, Vanadium(II) oxide

B. The formula and the name of the oxide is V₂O₃, Vanadium(III) oxide

C The formula and the name of the oxide is VO₂, Vanadium(IV) oxide

D. The formula and the name of the oxide is V₂O₅, Vanadium(V) oxide

The formula and the name of the various oxide can be obtained as follow:

A. Formula and name for oxide with 76% vanadium

Divide by their molar mass

V = 76 / 50.9 = 1.49

O = 24 / 16 = 1.5

Divide by the smallest

V = 1.49 / 1.49 = 1

O = 1.5 / 1.49 = 1

Thus, the empirical formula of the compound is VO and the name is Vanadium(II) oxide

B. Formula and name for oxide with 68% vanadium

Divide by their molar mass

V = 68 / 50.9 = 1.34

O = 32 / 16 = 2

Divide by the smallest

V = 1.34 / 1.34 = 1

O = 2 / 1.34 = 1.5

Multiply by 2 to express in whole number

V = 1 × 2 = 2

O = 1.5 × 2 = 3

Thus, the empirical formula of the compound is V₂O₃ and the name is Vanadium(III) oxide

C. Formula and name for oxide with 61% vanadium

Divide by their molar mass

V = 61 / 50.9 = 1.2

O = 39 / 16 = 2.4375

Divide by the smallest

V = 1.2 / 1.2 = 1

O = 2.4375 / 1.2 = 2

Thus, the empirical formula of the compound is VO₂ and the name is Vanadium(IV) oxide

D. Formula and name for oxide with 56% vanadium

Divide by their molar mass

V = 56 / 50.9 = 1.1

O = 44 / 16 = 2.75

Divide by the smallest

V = 1.1 / 1.1 = 1

O = 2.75 / 1.1 = 2.5

Multiply by 2 to express in whole number

V = 1 × 2 = 2

O = 2.5 × 2 = 5

Thus, the empirical formula of the compound is V₂O₅ and the name is Vanadium(V) oxide

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The Empirical formula of the compound is C₅H₅O.

and molecular formula of the compound is  C₁₀H₁₀O₂.

mass of C in the compound = (196g CO2)x (12.0 g C/44.0 g CO2) = 53.45g C

mass of H in compound = (40.2 g H2O) x (2.0 g H /18.0 g H2O) = 4.46 g H

mass of O in compound = 72.3 g total - 53.45 g C - 4.46 g H = 14.39 g O

now convert mass of each element to moles

53.45 g C x (1 mole C/12.0 g C) = 4.45 moles C

4.46 g H x (1 mole H/1.0 g H) = 4.46 moles H

14.39 O x (1 mole O/16.0 g O) = 0.899 moles O

Divide each by 0.899 to get C₅H₅O, which has a mass of 81 g

double that to get C₁₀H₁₀O₂ with mass of 162 g.

This is a "classic" example of a combustion analysis problem.

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Answer:

Malleability means that metals can be hammered into sheets and foils. For example, aluminium foils are used for wrapping food stuffs, silver foils are used for decorative purposes on sweets and fruits. Ductility means that metals can be drawn into wires. Gold and silver wires are used in ornaments.

and For jewellery and ornaments, gold, platinum and silver are being used. For building purposes, iron and steel can be used. Iron and aluminium are used as utensils. The thermometer uses mercury and helps to monitor the temperature.

Explanation:

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If the volume of the gas is increased to 9.90 l (at constant temperature), then its pressure will be 373 mmg.

According to Boyle's law, if the temperature of a gas is constant then the volume and pressure of the gas can be in relation to each other at different times.

We are given:

The initial volume of the gas V1 =  4.90 L

The initial pressure P1 = 755 mmg

The final volume of the gas V2 = 9.90 L

The final pressure of the gas P2 = ?

Using Boyle's law equation we can find the final pressure.

The equation is

P1V1 = P2V2

P2 = P1V1/V2

P2 = 755 x 4.90 / 9.90

P2 = 373 mmg

Thus, the final pressure is 373 mmg. Hence we can conclude that as the pressure decreases then volume of gas increases.

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Around the cuts you want the transition to appear on, add in and out points.

You can build a transition from one state in the lifecycle to another state using the new Transition dialog box. You can additionally specify which roles are permitted to move the object through this transition by using this feature.

A solute in a gaseous, liquid, or solid phase can dissolve in a solvent to create a solution through the process of dissolution.

Solubility. The greatest concentration of a solute that may dissolve in a solvent at a specific temperature is known as solubility.

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Answer:

A charged particle is called an ion.

A charged particle is called an ion.

Any atom or group of atoms that bears one or more positive charge is called cation and one or more negative charge is called anion.

Answer:

9

Explanation:

The mass will only be 9 if there are 4 neutrons, hope this helps

The volume of fuel is 6 liters and the temperature is about 300 degrees. Gasoline laws relate to volume, strain, temperature, and amount of fuel. New fuel volume when the temperature drops to 200 ok: the old way to fine-tune gasoline. 273 ok (0°C) and pressure 1.00 atm.

Temperature is a measure of hot or cold expressed in many scales, including Fahrenheit and Celsius. Temperature indicates the route wherein heat energy will spontaneously waft—i.e., from a hotter body (one at a better temperature) to a colder frame (one at a decreased temperature). warmness is the overall energy of the motion of the molecules of a substance, while temperature refers back to the measure of the average energy of the motions of the molecules inside the substance.

Temperature is just a size that shows the average kinetic strength of one atom or molecule. hence, whilst we say something is hot or bloodless, we're normally using some other reference factor to outline the hotness and coldness of a frame. A thermometer is a tool that measures temperature. it can measure the temperature of a stable along with food, a liquid inclusive of water, or fuel along with air.

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The mass of 6.022*10*23 atoms, molecules, or formula units make up one mole of a substance, which is known as the molar mass. This value is given in grams per mole.

The mass of a sample of a chemical compound divided by the quantity, or number of moles in the sample, measured in moles, is known as the molar mass of that compound. A substance's molar mass is a bulk characteristic rather than a molecular one.

Atomic masses:

Number of atoms:

S - 1; O - 4; H - 2;

Molar mass =  32.06 + (1.01 * 2) + (16 * 4)

                   = 98.08 g/mol

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The empirical formula of a sample of a compound that contains 72.0 g of C. 18.0 g of H, and 28.0 g of N is C₃H₉N.

Empirical formula is the notation indicating the ratios of the various elements present in a compound, without regard to the actual numbers.

The empirical formula of a compound can be calculated as follows:

C = 72.0g

H = 18.0g

N = 28.0g

Next, we divide by the atomic mass of each element as follows:

Next, we divide by the smallest mole as follows:

The empirical ratio is 3:9:1, hence, the empirical formula of the compound is C₃H₉N.

The options to the incomplete question are as follows:

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Answer:

Explanation:

a chemical reaction is a process in which the some substances go into reactant and some into products , the reactant molecule produce the new molecules in the form of product, it's also called the breaking of chemical bonds and forming the new bonds .

Polypropylene is considered as safe for use. The chemicals found in plastic products are proven to contribute to some cancers.

Its usage in high temperature applications is constrained by its high thermal expansion coefficient.

Heavily resistant to both aromatic and chlorinated solvents. It is vulnerable to UV damage.

It is well known for being challenging to paint because of its low bonding capabilities.

It is highly flammable.

Plastic containers, component parts for machinery and equipment, and even fibers and textiles are only a few applications for polypropylene.

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Answer:

D

Explanation:

The heating, rising, cooling, and sinking cycles are called convection currents. 2. A version of this same process, occurring in the mantle, is thought to be the force behind plate tectonics. ... Scientists suggest that differences in density cause the hot, plastic-like rock to be forced upward toward the surface.

0.4988699069454786 Moles of cobalt atoms are in 29.4 grams of cobalt.

In order to convert  grams of cobalt into moles of cobalt :

n = m / M,

n - number of moles.

m in grams  - specific mass.

M is the molar mass of this material.

n = 29.4 g / 58.933200 g/mol

n = 0.4988699069454786 moles

A mole is defined as 6.0221076 × [tex]10^{23}[/tex]  of any chemical unit, be it atoms, molecules, ions or others. A mole is a convenient unit to use because any substance has a large number of atoms, molecules or otherwise.

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Answer:

the answer is 0,000423

Explanation:

according to 3SF

2 hydrogen ions (protons; H-) would need to bond with the carbonate anion to create carbonic acid.

One carbon-oxygen double bond and two carbon-oxygen single bonds make up the structure of carbonic acid, as can be seen from the example given above. One hydrogen atom is joined to each of the oxygen atoms involved in a single bond with the carbon.

In the dimers of carbonic acid, bifurcated hydrogen bonds frequently occur, creating a complicated picture with several orbital interactions of different intensities. The lowest energy dimers are made up of two anti-anti monomers interacting through the strongest C=OH-O hydrogen bonds.

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