Which of the following is the basis for arranging the elements in the modern periodic table?

Answer:

Chemical energy is converted into thermal and mechanical energy while kinetic energy into potential energy.

Explanation:

As the breakdown of food started, the chemical energy present in the food substances converted into thermal energy and mechanical energy. Thermal or heat energy is used to maintain the body's temperature while mechanical energy is used in other activities such as movement of muscles. Kinetic energy is also converted into potential energy when the object moves from top of a place such as hill.

As the food burned, chemical energy was transformed into thermal energy. Thus, a form of potential energy was converted to a form of kinetic energy.

Hope I helped! :)

Answer:

The correct answer is option c. "a liquid vaporizes and condenses at the same rate"

Explanation:

In chemistry, dynamic equilibrium is defined as a state where the reaction rate of a forward reaction is equal to the reaction rate of the backward reaction. In this case, the reactions that participate in the system are the vaporization of a liquid and the condensation of a gas. Therefore, dynamic equilibrium is established when a liquid vaporizes and condenses at the same rate.

Answer:

1. False, water can't because its liquid

2. True, it dissolves more substances than any other liquid

3. False,stirring speeds up the rate of dissolving

Hope this helped

Answer:

Fish, marine mammals and seabirds are being injured and killed by plastic corruption /pollution, and it is believed that 700 species could go deceased because of it. ... Losses are generally influenced by the ingestion of plastics, starvation, suffocation, virus, drowning and entrapment.

You can thank me and google

) Copper density= 8.96 g/cm³ Copper volume= 51.3c.m.3  Copper density = M/V8.96= M/51. M= 459.68g.m.

Answer:

350J

Explanation:

Based on the first law of thermodynamics, which is the law of conservation of energy, energy can neither be created nor lost but can only be transformed. This implies that energy input of a system must equate the energy output as no energy can be lost.

In this case regarding an unlit match that contains 1000J of chemical energy. It burns to emit light energy and heat/thermal energy. If the amount of emitted thermal energy measured is 400J and the remaining/left over amount of chemical energy is 250J, this means that the missing amount of energy has been emitted as light energy.

To find the amount of light energy emitted, we say;

Amount of chemical energy - (thermal energy emitted + remaining chemical energy)

= 1000 - (400 + 250)

= 1000 - 650

= 350J

Hence, the amount of light energy emitted is 350J. This satisfies the law of conservation of energy because the output energy is equal to the total energy in the system.

Answer:

[tex] \boxed{\sf Volume \ of \ plastic \ used = 10.14 \ cm^3} [/tex]

Given:

Mass = 14.0 g

Density ([tex] \rho [/tex]) = 1.38 g/cm³

To Find:

Volume (V)of the plastic used to make water bottle

Explanation:

Formula:

[tex] \boxed{ \bold{Density \ (\rho) = \frac{Mass \ (m)}{Volume \ (V)}}}[/tex]

Substituting value of m & density in the formula:

[tex] \sf \implies 1.38 = \frac{14.0}{V} \\ \\ \sf \implies V = \frac{14.0}{1.38} \\ \\ \sf \implies V = 10.14 \ cm^3 [/tex]

[tex] \therefore [/tex]

Volume of the plastic used to make water bottle = 10.14 cm³

Answer:

It will be 1663500mg

Explanation:

Answer:

56.0kJ/mol

Explanation:

The reaction of NaOH with HCl is:

NaOH + HCl → H₂O + NaCl + ΔH

Where ΔH is the heat of reaction that is released per mole of reactants,

The moles that reacts are:

100mL = 0.1L * (1mol / L) = 0.1 moles reacts

To find the heat released in the coffee cup calorimeter, you use the equation:

Q = m×ΔT×C

Where Q is heat released,

m is mass of the solution

ΔT is change in temperature (Final temperature - Initial temperature)

C is specific heat of the solution (4.18J/g°C)

Mass of the solution is:

100mL + 100mL = 200mL

Density of the solution is 1.0g/mL. The mass is 200g

Change in temperature is 31.3°C - 24.6°C = 6.7°C

Replacing:

Q = m×ΔT×C

Q = 200g×6.7°C×4.18J/g°C

Q = 5601.2J

This is the heat released per 0.1mol. The heat released per mole (Enthalpy change for the neutralization of HCl by NaOH is:

5601.2J / 0.1 moles = 56012J / mol =

56.0kJ/mol

Boiling Point, Melting Point, Viscosity, Surface Tension. Decrease: Vapor Pressure.

Answer:

Bent or Anglar, Polar

Explanation:

Took Test

Answer:

a. [Weak acid] = 0.099999949M

[Conjugate base = 5.0119x10⁻⁸M

b.  pH = 1.84. Is not a good buffer

c. pH = 6.97

Explanation:

a. To find pH of the buffer we must use Henderson-Hasselbalch formula:

pH = pKa + log [Conjugate base] / [Weak acid]

2.0 = 8.3 + log [Conjugate base] / [Weak acid]

5.01x10⁻⁷ = [Conjugate base] / [Weak acid] (1)

As concentration of the buffer is 0.1M = [Conjugate base] + [Weak acid] (2)

Replacing (2) in (1):

5.01x10⁻⁷ = 0.1M - [Weak acid] / [Weak acid]

5.01x10⁻⁷ [Weak acid] = 0.1M - [Weak acid]

[Weak acid] = 0.099999949M

[Conjugate base] = 5.0119x10⁻⁸M

b. The conjugate base reacts with the HCl. Moles of HCl are:

1.5x10⁻³L * (3.0mol / L) = 4.5x10⁻³ moles HCl

As the conjugate base contains just 5x10⁻⁸ moles. Almost all HCl doesn't react and pH =

[H⁺] = 4.5x10⁻³ moles + 1x10⁻² moles (Initial moles H⁺) / L = 0.0145M

pH = -log [H⁺]

pH = 1.84

As the concentration of the conjugate base is <<< than weak acid. In this pH, Tris is not a good buffer. As general rule a good buffer works pH between pKa ± 1.

c. Now, NaOH reacts with the weak acid producing conjugate base.

The new moles are:

[Weak acid] = [Weak acid] = 0.099999949M - 4.5x10⁻³ = 0.0955

[Conjugate base] = 5.0119x10⁻⁸M + 4.5x10⁻³ = 4.5x10⁻³

pH = pKa + log [Conjugate base] / [Weak acid]

pH = 8.3 + log [4.5x10⁻³] / [0.0955]

pH = 6.97

Following are the response to the given points:

For question a)

The concentration of Tris buffer [tex]\text{(Tris buffer)} = 0.1\ M[/tex]

Using formula:

[tex]\text{[ Tris buffer ] = [ Conjugate base ] + [ Acid ]}[/tex]

[tex]0.1 M = \text{ Conjugate base +Acid } \\\\ \text{Acid} = 0.1\ M - \text{ Conjugate base } .............(a)[/tex]

Using the Henderson-Hasselbalch equations

[tex]\to pH = pKa + \log \frac{\text{ Conjugate base }}{ Acid}\\\\\to 2.0 = 8.3 + \log \frac{\text{ Conjugate base }}{ Acid}\\\\\to \log \frac{\text{ Conjugate base }}{ Acid} = 2.0 - 8.3\\\\\to \log \frac{\text{ Conjugate base }}{ Acid} = - 6.3\\\\\to \frac{\text{ Conjugate base }}{ Acid}= 10-6.3\\\\\to \frac{\text{ Conjugate base }}{ Acid} = 5.01 \times 10^{-7}\\\\\to \text{Conjugate base} = 5.01 \times 10^{-7} \times \ Acid ..............(b)[/tex]

Putting the value of equation (b) in equation (a):

[tex]\text{Acid } = 0.1\ M - 5.01 \times 10^{-7}\\\\\text{Acid } = 0.1 M \ ( approx.)[/tex]

from equation (b)

[tex]\to \text{Conjugate base} = 5.01 \times 10^{-7} \times 0.1\ M= 5.01 \times 10^{-8}\ M\\\\[/tex]

Therefore,

[tex]\to \text{Acid} = 0.1\ M\\\\ \to \text{Conjugate base} = 5.01 \times 10^{-8}\ M[/tex]

For question b)

[tex]\to \text{Number of moles of HCl} = 3.0\ M \times 0.00152\ L= 0.0045 \ moles\\\\\to \text{Number of moles Conjugate base in 1 L of buffer} = 5.01 \times 10^{-8}\ M \times 1\ L = 5.01 \times 10^{-8}\ moles\\\\ \to \text{Number of moles of weak acid} = 0.1\ M \times 1\ L = 0.1\ moles\\\\[/tex]

Now we need all the conjugate bases for neutralizing the [tex]HCl[/tex]

therefore

Calculating the molarity of  [tex]HCl[/tex] in the solution [tex]= \frac{0.0045\ moles}{1\ L} = 0.0045\ M[/tex]

[tex]\to H^+ \ in \ HCl = 0.0045 \ M\\\\p_H = 2.0\\\\\therefore \\\\ H^+ \ in \ buffer = 10^{-2}\ M = 0.01\ M \ ( \because \ p_H = - \log [ H^+]\ and\ [ H^+ ] = 10-p_H )[/tex]

Now Total concentration of [tex]H^+ \ i.e\ [H^+][/tex]

[tex]\to Total = 0.0045 + 0.01 = 0.0145\ M\\\\\to pH = - \log 0.0145\\\\\to pH = - ( - 1.84 )\\\\\to pH = 1.84\\\\[/tex]

For question c)

Number of moles of [tex]NaOH = 3.0 \ M \times 0.00152\ L= 0.0045\ moles\\\\[/tex]

[tex]\to \text{Number of moles Conjugate base ( say A-) in 1\ L of buffer} = 5.01 \times 10^{-8}\ M \times 1 \ L = 5.01 \times 10^{-8}\ moles \\\\ \to \text{Number of moles of weak acid ( say HA )} = 0.1\ M \times 1\ L = 0.1\ moles[/tex]

Now ICF table is :

[tex]HA + OH^- \longrightarrow A^- + H_2O[/tex]

[tex]\text{I 0.1 mol 0.0045 mol 5.01 x 10-8 mol}\\\\\text{C - 0.0045 mol - 0.0045 mol + 0.0045 mol}\\\\\text{F 0.0955 mol 0 mol 0.0045 mol ( approx. )}\\\\[/tex]

Using Henderson-Hasselbalch:

[tex]\to pH = 8.3 + \log \frac{0.0045}{ 0.0955} \\\\\to pH = 8.3 + \log 0.04712\\\\\to pH = 8.3 - 1.3268\\\\\to pH = 6.97[/tex]

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Answer:

1. A PROTON HAS A +1 CHARGE

2. A PROTON HAS A MASS OF ABOUT 1.0 amu

3. THE NUMBER OF PROTONS DETERMINES THE IDENTITY OF AN ELEMENT

Explanation:

The proton is one of the three particles that make up the atom. Proton is a positively charge particle with a +1 charge. It neutralizes the negative charge of the electrons outside of the nucleus of the atom as the proton are located inside the nucleus of the atom. Proton has a mass of 1.0 amu which is about 1.67 * 10^-27 kg. The addition of the proton and the neutrons gives the molar mass of the atom.

Also, the identity of the cell that is the atomic number which gives the position of the element in the periodic table and also shows the individual characteristics of the atoms is determined by the number of protons in the nucleus of the atoms.

All the above options are true in regard to a proton.

Answer: the mass will be same

Answer:

the mass wouldnt be the same because of the ashes in the jar

Explanation:

Answer:

51.51 amu .

Explanation:

The atomic mass 52 amu has percentage of 79.5%

The atomic mass 49 amu has percentage of 8%

The atomic mass 50 amu has percentage of 12.5 %

Average atomic pass will be weighted average of their atomic weights

= 52 x .795 + 49 x .08 + 50 x .125

= 41.34 + 3.92 + 6.25

= 51.51 amu .  

Answer:

We can be safe in a science laboratory by following all directions and wearing gloves, goggles to protect ourselves.

Explanation:

If we don't follow the rules then we might cuase a problem that we didn't want to happen and we need to wear protective gear because we need to stay safe

Answer:

a

Explanation:

Explanation:

Hey there!!

We generally use s,p,d,f formula.

So, let's do with it.

1.Neon

Atomic no. = 10

So, Its electronic configuration is;

[tex] = 1 {s}^{2} .2 {s}^{2} 2 {p}^{6} [/tex]

2.Zinc.

Atomic no. = 30

So, it's electronic configuration is;

[tex] = 1 {s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{2} 3 {p}^{6} 4 {s}^{2} 3 {d}^{10} [/tex]

3. Tungsten.

Atomic no. = 74.

So, it's electronic configuration is;

[tex] = 1 {s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{2} 3 {p}^{6} 4 {s}^{2} 3 {d}^{10}4 {p}^{6} 5 {s}^{2} 4 {d}^{10} 5 {p}^{6} 6 {s}^{2} 4 {f}^{14} 5 {d}^{4} [/tex]

4. Magnesium.

Atomic no. = 12

So, the electronic configuration is ;

[tex] = 1 {s}^{2} 2 {s}^{2} 2 {p}^{6}3 {s}^{2} [/tex]

Hope it helps...

Answer:

a heterogeneous mixture,-two substances present; two phases present

a homogeneous mixture- two substances present; one phase present

a pure substance- one substance present- one phase present

no correct response-one substance present; two phases present

Explanation:

When two substances are mixed, the mixture may be homogenous or heterogeneous. If a mixture is homogenous, then the two substances form a single phase, e.g ethanol and water.

On the other hand, a heterogeneous mixture is divided into two distinct phases, e.g kerosene and water mixture.

A single substance can only give one phase, no substance can simultaneously give two phases of the same substance in the same physical state.

Similarly, a pure substance always consists of a single phase.

Answer:

Explanation:

volume = 60cm^3

Answer:

The correct answer is:

after the vein is entered (A.)

Explanation:

The procedure in the question describes venopuncture.

Venopuncture is the method of aseptically collecting blood into the right sample containers. Using a stopper-punturing needle and a vacuum tube, the following procedure is followed:

Answer:

Explanation:

Plant cell because its shape is rectangular

Answer:

This is required answer.

Explanation:

Given that,

1,2,3,4,5,6-hexachlorocyclohexane

(a). We need to draw 1,2,3,4,5,6-hexachlorocyclohexane with all the chloro groups in axial positions

Using given data

We draw 1,2,3,4,5,6-hexachlorocyclohexane with all the chloro groups in axial positions.

When we say that all the chloro groups in axial position that means axial bonds are vertical.

(b). We need to draw 1,2,3,4,5,6-hexachlorocyclohexane with all the chloro groups in equatorial positions

Using given data

We draw 1,2,3,4,5,6-hexachlorocyclohexane with all the chloro groups in  equatorial positions.

When we say that all the chloro groups in equatorial position that means axial bonds are horizontal.

Hence, This is required answer.

Answer:

a) Heterogeneous mixture (b) Homogenous mixture (c) Pure substance (d) Pure substance

Explanation:

Homogenous mixtures contains mixture of substances with similar proportions while Heterogenous mixture contains substances with a varying proportion.

Answer:

[tex]pKa=3.58[/tex]

Explanation:

Hello,

In this case, since the pH defines the concentration of hydrogen:

[tex]pH=-log([H^+])[/tex]

[tex][H^+]=10^{-pH}=10^{-3.4}=3.98x10^{-4}[/tex]

And the percent ionization is:

[tex]\% \ ionization=\frac{[H^+]}{[HA]}*100\%[/tex]

We compute the concentration of the acid, HA:

[tex][HA]=\frac{[H^+]}{\% \ ionization}*100\%=\frac{3.98x10^{-4}}{66\%} *100\%\\\\[/tex]

[tex][HA]=6.03x10^{-4}[/tex]

Thus, the Ka is:

[tex]Ka=\frac{[H^+][A^-]}{[HA]}=\frac{3.98x10^{-4}*3.98x10^{-4}}{6.03x10^{-4}}\\ \\Ka=2.63x10^{-4}[/tex]

So the pKa is:

[tex]pKa=-log(Ka)=-log(2.63x10^{-4})\\\\pKa=3.58[/tex]

Regards.

Answer:

No, NaCl is formed by an ionic bond, and CCl4 would be formed by covalent bonds.

Explanation:

NaCl is an ionic bond because of their opposite charges while carbon and chlorine are sharing their electrons making it a covalent bond.

Taking into account the definition of ionic and covalent bond, the bonds that chlorine forms with sodium (to form NaCl) and with carbon (to form CCl₄) are different in both compounds.

An ionic bond is a type of chemical bond that occurs when one atom gives up an electron to the other, in order for both to achieve electronic stability.

This union normally occurs between metal and nonmetal elements with different electronegativity, which means that the elements have different capacity to attract electrons.

In other words, an ionic bond is produced between metallic and non-metallic atoms, where electrons are completely transferred from one atom to another. During this process, one atom loses electrons and another one gains them, forming ions. Usually, the metal gives up its electrons forming a cation to the nonmetal element, which forms an anion.

The covalent bond is the chemical bond between atoms where electrons are shared, forming a molecule. Covalent bonds are established between non-metallic elements, such as hydrogen H, oxygen O and chlorine Cl. These elements have many electrons in their outermost level (valence electrons) and have a tendency to gain electrons to acquire the stability of the electronic structure of noble gas.

In the case of NaCl, Na is a metal while Cl is a nonmetal. So NaCl is an ionic bond.

On the other hand, in the case of CCl₄ both C and Cl are two non-metallic elements. So CCl₄ is a covalent bond.

In summary, the bonds that chlorine forms with sodium (to form NaCl) and with carbon (to form CCl₄) are different in both compounds.

Learn more about

ionic bond:

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covalent bond:

https://brainly.com/question/24900155?referrer=searchResults

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Answer:

(a) 3-bromo-1-chlorobutane

(b) 2-bromo-1-chlorobutane

(c) 3,3-dimethylcyclopentan-1-ol

(d) 1,1,2,2-tetrachloropropane

(e) 1-ethylcyclopentan-1-ol

Explanation:

We can analyze each reaction:

(a) 4-Chlorobut-1-ene + HBr

In this reaction, we have an alkene. So, we will have an addition reaction, the nucleophile "[tex]Br^-[/tex]" will be added to the most substituted carbon. In this case carbon 3 to produce 3-bromo-1-chlorobutane.

(b) 1-Chlorobut-1-ene + HBr

In this reaction, we also have an alkene. So, we will have an addition reaction, the nucleophile "[tex]Br^-[/tex]" will be added to the most substituted carbon. In this case carbon 2 to produce 2-bromo-1-chlorobutane.

(c) 4,4-Dimethylcyclopentene + H2O, H+

In this reaction, we have an alkene. So, we will have an addition reaction, the nucleophile "[tex]H_2O[/tex]" will be added to the most substituted carbon. In this case carbon 3 to produce 3,3-dimethylcyclopentan-1-ol.

(d) Propyne  + 2HCl

In this reaction, we have an alkyne. So, we will have an addition reaction, the nucleophile "[tex]Cl^-[/tex]" will be added to the most substituted carbon, but we have 2 moles of the nucleophile, so would be added 2 times and we will have as product  1,1,2,2-tetrachloropropane.

(e) Cyclopentylethene + H3O+

In this reaction, we have an alkene. So, we will have an addition reaction, the nucleophile "[tex]H_3O^+[/tex]" will be added to the most substituted carbon. But in this case, the carbon cation would be produced in carbon 1 of the ethene. So, we can have a hydride shift to produce a tertiary carbocation. With this in mind the nucleohile will be addde to this tertiary carbocation and we will have 1-ethylcyclopentan-1-ol.

See figure 1 to further explanations

Answer:

this old man looks so weird ..

Explanation:

but i m sorry .....u know the reason very well

do u wanna be my friend .