write the name of the first twenty elements with their symbols and their atomic number​

Answer:

Difference in temperature.

Explanation:

Conduction is the movement of heat energy through a substance or from one substance to another by direct contact of atoms and molecules. Heat moves directly from one molecule to another. The heat energy speeds up the movement of the atoms and they collide with other molecules setting them into faster motion.

Because 5.00 mL is a small amount, the best tool he could use is a pipette.

Pipette or sometimes spelled as pipet can be used to transport liquid samples. It is made out of glass or plastic and can is usually used to transfer measured volumes of liquid from one container to another.

Before the pipette was invented, scientists used to use straws and they would suck in the samples carefully.

Hence 5.00 mL is a small amount, the best tool he could use is a pipette.

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Mass of magnesium (Mg) = 0.12 g

Atomic mass of Mg = 24.31 g/mol (from periodic table)

Number of moles of Mg = Mass of Mg / Atomic mass of Mg

= 0.12 g / 24.31 g/mol

= 0.00494 mol

Number of moles of O₂ = Number of moles of MgO produced / 2

= 0.00650 mol / 2

= 0.00325 mol

When the experiment is performed without the crucible cover, the magnesium oxide created reacts with any oxygen in the air. When more oxygen reacts with the magnesium, the amount of magnesium oxide generated will be larger than when the experiment was run without a cover on the crucible.

Also, any water vapour or other gases in the air may react with the magnesium oxide, influencing the final product's mass. As a result of the existence of extra reactants in the air, the mass of magnesium oxide formed will change when the crucible is not covered.

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Answer:

The correct option is;

Cylinder A contains a gas that has a temperature closest to absolute zero

Explanation:

From the kinetic theory of gases, the average speed of a gaseous molecule is found from the following equation;

\(v_{rms} = \sqrt{\frac{3\cdot R \cdot T}{MW} }\)

Where:

\(v_{rms}\) = rms speed which is the square root of the average of the velocities of the gas molecules squared which is used in place of the average of the gas molecules as the sum of the velocities of all the gas molecules in the cylinder is zero

R = Universal gas constant = 8.3145 J/(mol·K)

MW = Molecular weight of the gas

Hence where we have;

\(v_{rmsA}\) = Average velocity of gas A = 0.0000001 m/s

\(v_{rmsB}\) = Average velocity of gas B = 0.3 m/s

Since, R and MW are constant for the gas in cylinder A constant, therefore, as \(v_{rmsA}\) ≈ 0 m/s, the temperature, \(T_A\), of gas A is closest to absolute zero.

Answer:

30 g

Explanation:

According to Mendeleev's theory, the total mass of the reactants and products are the same.

In a process known as nucleosynthesis, fusion powers stars and creates nearly all elements. As a main-sequence star, the Sun generates its energy through the nuclear fusion of hydrogen nuclei into helium. Each second, the Sun's core fuses 620 million metric tons of hydrogen and produces 616 million metric tons of helium. The fusion of lighter elements in stars has energy and mass that is always present.

Nuclear fusion reactions power the Sun and other stars. A fusion reaction occurs when two light nuclei combine to form a single heavier nucleus. Because the total mass of the resulting single nucleus is less than the mass of the two original nuclei, the process releases energy. The remaining mass is converted into energy.

The occurrence of nuclear fusion in stars causes energy to be released from the core in the form of heat or light, or sometimes another nucleus. According to this, nuclear fission in stars virtually releases all elements.

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Answer:

thor.. is 90 years old ?

Explanation:

thats how i remembered it lol

Thorium  an element , future in radioactive and nuclear reactors as well as nuclear science.

It is defined as a substance which cannot be broken down further into any other substance. Each element is made up of its own type of atom. Due to this reason all elements are different from one another.

Elements can be classified as metals and non-metals. Metals are shiny and conduct electricity and are all solids at room temperature except mercury. Non-metals do not conduct electricity and are mostly gases at room temperature except carbon and sulfur.

The number of protons in the nucleus is the defining property of an element and is related to the atomic number.All atoms with same atomic number are atoms of same element.Elements combine to give compounds.

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Answer:

CH4

- 4 electron

- 0 electron

- the geometry of Ch4 is tetrahedral

AlF3

- 3 electron

- 0 electron

- the geometry is trigonal planar

CCl4

- 4 electron

- 0 electron

- the geomotry is tetrahedral

SeH2

- 2 electron

- 2 electron

- the geometry is V shape

Answer:

1. 3.6 x 10^-2

2. 2 x 10^2

3. 5 x 10^8

4. 1.8 x 10^-1

Explanation:

Neutralization reactions are typically exothermic, which means they release heat energy. As a result, they are enthalpically favored, or thermodynamically favorable.

The energy released in a neutralization reaction is due to the formation of ionic bonds in the salt product and the breaking of hydrogen bonds in the acid and base reactants. The ionic bonds in the salt are stronger than the hydrogen bonds in the acid and base, so the reaction releases energy as these bonds are formed.

The release of heat energy in a neutralization reaction makes it energetically favorable, or enthalpically favored, which means that it will occur spontaneously under standard conditions. The release of heat energy is also why neutralization reactions are often used in exothermic heat-absorbing applications, such as in heat-pack warmers or in some chemical heating and cooling systems.

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The temperature of the physics book increasing as the chemistry book slides across it is the difference when motion is faster.

Because the molecules have kinetic energy, molecular motion rises with rising temperature and decreases with falling temperature. At absolute zero, molecular motion comes to a complete standstill.

This is defined as the degree of hotness or coldness of a body and it increases when there is more friction.

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Answer:

The speed of the particles increases for both books, and the temperature of the physics book increases even more.

Explanation:

edmentum

Answer:

I think it's the last one I'm sorry if it's wrong

Explanation:

it sounds like it fits

Answer:

sp³-s sigma bond.

Hope that was the answer

True

Aldehydes are alkane-derived compounds containing the functional group (-CO-) located at the end of the parent carbon chain

The general structure is R-CHO with the molecular formula CnH2nO

Naming is generally the same as the alkane by replacing the suffix with -al

Acetaldehyde(ethanal) is an aldehyde which has 2 C atoms  with formula

\(\boxed{\bold{C_2H_4O}}\)

The bond between the C atom and the O atom is a double bond

So the C atom has a single bond with H and alkyl and double bonds with O

R - C - H

     ||

    O

Answer:

1d and 2d is the answer. Hope it helps

Following are the KMT's five central tenets: The particles in a gas are constantly moving at random speeds, their total volume is tiny, they do not interact with one another physically, and their collisions are entirely elastic.

Gases will depart from the ideal gas law when the Kinetic Molecular Theory's five postulates fail, and there are five postulates in total.

The relationship between a gas particle's average kinetic energy and temperature is direct. The speed at which the gas molecules move rises with temperature.

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Answer:Argon is an element on the periodic table. It is a member of the noble gasses, meaning that it is a monoatomic pure gas. In other words, argon gas particles are simply pure single atoms of argon. ... Finally, water is a polyatomic molecule H2O composed of two atoms of hydrogen and one atom of oxygen.

Explanation:

The final volume of the system is 20.75 liters. This can be calculated by using the ideal gas law equation, PV = nRT, where:

Since the change in internal energy is -325 J, and the heat lost is 155 J, we can calculate the temperature of the system using the equation ΔU = nCvΔT, where Cv is the molar heat capacity of an ideal gas at constant volume (7/2 R).

Plugging in our values, we get ΔT = -325/(7/2 * 0.08206 * 4) = -6.5 K. We can then use this temperature and the pressure from before to calculate the volume of the system using the ideal gas law, resulting in V = nRT/P = (4 mol)(0.08206 L atm mol-1K-1)(273.5 K)/(1.00 atm) = 20.75 L.

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After the solutions are mixed, a white precipitate of calcium oxalate will form, while the Li+ and Cl- ions will remain in the resulting solution.

When the solutions of CaCl2 and Li2C2O4 are mixed, a double displacement reaction occurs. The calcium ions (Ca2+) from CaCl2 react with the oxalate ions (C2O42-) from Li2C2O4 to form a precipitate of calcium oxalate (CaC2O4) according to the following equation:

CaCl2 + Li2C2O4 → CaC2O4 + 2 LiCl

Since calcium oxalate is insoluble in water, it will form a solid precipitate. The precipitate will appear as a white, finely divided solid in the solution. The remaining ions, Li+ and Cl-, will stay in the solution.

Therefore, after the solutions are mixed, a white precipitate of calcium oxalate will form, while the Li+ and Cl- ions will remain in the resulting solution.

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2Al + 3Br\(_{2}\) ⇒2AlBr\(_{3}\)

Answer:

Explanation:

En este caso para formular los compuestos, debes identificar el grupo funcional principal de la molecula. Una vez que eso está hecho, puedes intentar formularlo.

Empezaremos primero identificando el grupo funcional principal de la molécula, para luego formularlo correctamente.

Dietil eter: la terminación eter al final significa que pertenece al grupo de los éteres, el cual tiene como formula general R - O - R.

Etanol: debido a que termina en ol, este grupo pertenece a los alcoholes. Para formularlo solo se dibuja la molecula del etano, junto a un enlace con el grupo OH, como su formula general R - OH.

Propanotriol: igualmente termina en ol, por lo tanto es un alcohol, sin embargo, en este caso, tambien tiene la terminación prefija tri, asi que significa que hay 3 grupos OH en la molecula.

Acido propanodioico: esta es sencilla, porque empieza como acido, y solo hay un grupo funcional que empieza así y son los acidos carboxilicos, es decir, el grupo COOH (R - COOH) que es el carboxilo. Tiene el prefijo di, antes del oico, por lo que son dos carboxilos presentes en la molecula.

Pentanal: el sufijo al, significa que pertenece al grupo de los aldehidos, en este caso, posee el grupo carbonilo H - C = O.

Pentano - 2,4 - diona: la terminación ona significa que pertenece al grupo de las cetonas, (R - CO - R), parecido a los aldehidos, con la diferencia de que tiene grupos alquilos en lugar de un hidrogeno.

Metanoato de metilo: la terminación ato de ilo, pertenece a los esteres, (R - COOR) derivado de los acidos carboxilicos.

De aqui en adelante solo mencionaré los grupos funcionales pues ya se explicó el por que, por sus terminaciones:

Ciclohexano - 1.3 - diol: este pertenece a los alcoholes.

Acido heptanoico: acido carboxilico

Ciclobutil metil eter: eteres

Acetato de etilo: ester

2-metilbenzaldehído: aldehído unido a un grupo aromatico como el benceno.

Ciclohexanona: un ciclo (cadena cerrada) unido a un grupo carbonilo.

Butanona: cetona.

Observa la foto adjunta para que veas la formulación de cada una:

Answer:

the particles expands

The molarity is 0.112 M. if that is prepared by dissolving 2.24 grams of naoh in enough deionized water to make 500.0 ml of solution .

Molarity is mathematically defined as Molarity = Number of moles of solute Volume of solution in litre. As the number of moles  solute is measured in mol and the volume of solution will be in litre . So, the unit of molarity is mol L - 1 .

Molarity  also known as molar concentration and is represented by “M”. For example,  solution of 1M of sodium chloride dissolved in water has a molarity of 1M. A number of moles of solute can be calculated by dividing mass by the molecular weight of the solute.

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Answer:

Chemical reaction, not physical

Explanation:

Answer:

A. A as concentration decreases.

Explanation:

A represents a reactant and B is a product, the concentration of the latter increases at the expense of the concentration of the former. Hence, A is the reactant of the chemical reaction as its concentration decreases.

Yes, a metal will always be produced at one electrode during electrolysis.

An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit.

An electrode can be anode or cathode. During electrolysis, that is , the decomposition of a chemical compound by electricity, a metal will be deposited at the cathode.

Thus, a metal will always be produced at one electrode during electrolysis.

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Answer: FALSE

Explanation: Often, gases rather than metals form at electrodes, especially if it involves the electrolysis of a solution.

Answer:

20 to 50 million

Explanation:

It woukd decrease.

I am sure its correct you can trust me becuase I took the test.

Answer:

The speed of the wave decreases.

Explanation:

When light waves do pass through a medium, any solid, liquid, or gas, the speed of the waves actually decreases. Solids are more dense than liquids, so they decrease the speed of light even more.


(I did the quiz btw!!)