What was the plum-pudding atomic model? A. A description of atoms being balls of positive charge with electrons scattered outside B. A description of electrons orbiting the nucleus of the atom C. A description of electrons scattered inside the atom D. A description of negative charges being suspended between balls of positive charge

Answer:

A chemical element

Explanation:

A chemical element consists of only one type of atom.

Answer:

2.01 A

Explanation:

Para esta pregunta debemos empezar por la semi-reaccion del plomo:

[tex]Pb^+^2~_(_a_q_)~+~2e^-~->~Pb_(_s_)[/tex]

Se intercambian dos electrones en la semi-reacción del plomo. Si tenemos en cuenta la ecuación:

[tex]n=\frac{I*t}{z*F}[/tex]

Donde:

n= Moles depositados

I= Intensidad de corriente (en Amperios)

z= Numero de electrones intercambiados

F= Constante de faraday = 96484 C/mol

t=tiempo (en segundos)

Que conocemos de esta ecuación?

Los moles (se pueden calcular a partir de la masa atómica del plomo, 207.2 g/mol)

[tex]2.6~g~Pb\frac{1~mol~Pb}{207.2~g~Pb}=0.0125~mol~Pb[/tex]

El tiempo (hay que convertirlo a segundos):

[tex]20~min\frac{60~s}{1~min}=1200~s[/tex]

Z (Numero de electrones)

De acuerdo a la semi-reacción son intercambiados 2 electrones.

Por lo tanto podemos resolver para "I":

[tex]I=\frac{n*z*F}{t}=\frac{0.0125~mol*2*96484\frac{C}{mol}}{1200~s}[/tex]

[tex]I~=~2.01~\frac{C}{s}=2.01~A[/tex]

Espero que sea de ayuda!

Answer:

[tex]1.63 \times {10}^{24} [/tex]

one atom of an element = 6.02 \times {10}^{23} atom

The mass of one atom of sulphur = 32g

The mass of one atom of aluminium = 27g

so one atom of aluminium = 6.02 \times {10}^{23}

27g of AL = 6.02 \times {10}^{23} atom

2.70g of AL = X atoms

Then you cross multiply ........

and get the answer

.

Answer:

The biological sample that pregnancy tests use to detect pregnancy is urine

Answer:

yes

Explanation:

the urine in the the tester will find hormones to determine if pregnant or not

Answer:

The government allocates a budget for research every year. The spending of that money is determined by government priorities. Some of the money is spent directly, in government-funded research centers.

Other money is distributed to other research institutions.

Money spent by other institutions for research has no government oversight.

Explanation:

Answer:

volcanic eruption.

mark my answer as brainlest......

Answer:

there is an increase by 0.18 V in the cell voltage.

Explanation:

The given equation of the reaction can be well written as

[tex]2AgCl_{(s)} + Zn _{(s)} \to 2Ag_{(s)} + 2 Cl^- _{(aq)}+ Zn^{2+}_{(aq)}[/tex]

By application of Nernst Equation ; we have the expression

[tex]E_{cell} = E^0- \dfrac{0,059}{n}log (\dfrac{[product]}{[reactant]})[/tex]

here in the above equation;

n = number of electrons transferred in the equation of the reaction

n = 2

Also;

[tex]E^0 = E_{cathode} - E_{anode}[/tex]

[tex]E^0 = E_{Ag^+/Ag} - E_{Zn^+/Zn}[/tex]

[tex]E^0 = +(0.80 \ V) - (-0..76 \ V)[/tex]

[tex]E^0 = (0.80 \ V +0..76 \ V)[/tex]

[tex]E^0 = 1.56 \ V[/tex]

If the zinc ion concentration is kept constant at 1 M; we have:

[tex]E_{cell} = E^0- \dfrac{0.059}{n}log (\dfrac{[product]}{[reactant]})[/tex]

[tex]E_{cell} = 1.56 - \dfrac{0.059}{2}log ({[Zn^{2+} ]}{[Cl^{2-}]})[/tex]

[tex]E_{cell} = 1.56 - \dfrac{0.059}{2}log (1)[/tex]

Since log(1) = 0

Therefore;

[tex]E_{cell} = 1.56\ V[/tex]

When the chlorine ion concentration is decreased from 1 M to 0.001 M; we have;

[tex]E_{cell} = E^0- \dfrac{0.059}{n}log (\dfrac{[product]}{[reactant]})[/tex]

[tex]E_{cell} = 1.56 - \dfrac{0.059}{2}log ({[Zn^{2+} ]}{[Cl^{2-}]})[/tex]

[tex]E_{cell} = 1.56 - \dfrac{0.059}{2}log ({[1*0.001^2}]})[/tex]

[tex]E_{cell} = 1.56 - 0.0295 \ * \ log ({[1*10^{-6}}]})[/tex]

[tex]E_{cell} = + 1.737 \ V[/tex]

The change in voltage = [tex]E_{cell} - E^0[/tex]

=( 1.737 - 1.56 )V

= 0.177 V

≅ 0.18 V

Thus; from the following observation; there is an increase by 0.18 V in the cell voltage.

The voltage of the cell increased by 0.18 V.

The equation of the reaction is; 2AgCl(s) + Zn(s) → 2Ag(s) + 2Cl– + Zn2+

We know that;

E°cell = 1.36 - (-0.76) = 2.12 V

If the cells are both at 1M concentration the Ecell = E°cell = 2.12 V

When the concentration of Cl- decreased from 1 M to 0.001 M

Ecell =  E°cell - 0.0592/n log Q

Substituting values;

Ecell = 2.12 V -  0.0592/2 log (1 × (0.001)^2)

Ecell = 2.298 V

Increase in voltage = 2.298 V - 2.12 V = 0.18 V

Learn more: https://brainly.com/question/165414

Answer:Drinking straw

Explanation: my quiz said so

The object that represents the best model of one of the phloem cells is the drinking straw.

Phloem may be defined as a type of vascular tissue in plants that significantly conducts the passage of sugars and other metabolic products from the leaves to the roots. This mediates the migration of sugar which is synthesized in the leaves during photosynthesis.

Apart from this, the phloem also regulates the movement of nutrients from the roots to the upper part of the body. This function of phloem cells shares homology with the object known as a drinking straw that mediates the transport of any fluid in both directions.

Therefore, a drinking straw is an object that represents the best model of one of the phloem cells.

To learn more about Phloem cells, refer to the link:

https://brainly.com/question/3138900

#SPJ2

Your question seems incomplete. The most probable complete question is as follows:

The mole is used to measure small particles like atoms and molecules.  The 4 moles of silver is equivalent to [tex]\bold{2.408 x 10^2^4 }[/tex] atoms.

Given here,

The number of atoms

[tex]\bold{2.408 x 10^2^4 }[/tex]

Number of moles = ?

1 mol of substance = [tex]\bold{ 6.02 x10^2^3}[/tex]

Hence,

moles of silver,

[tex]\bold {= \dfrac {2.408 x 10^2^4 } { 6.02 x10^2^3} }}\\\\\bold {= 4 mol}[/tex]

Therefore, the 4 moles of silver is equivalent to [tex]\bold{2.408 x 10^2^4 }[/tex] atoms.

To know more about mole concept, refer to the link:

https://brainly.com/question/20483253

Answer:

Side photo

A small still is separating propane and butane at 135 °C, and initially contains 10 kg moles of a mixture whose composition is x = 0.3 (x = mole fraction butane). Additional mixture (x = 0.3) is fed at the rate of 5 kg mole/hr. The total volume of the liquid in the still is constant, and the concentration of the vapor from the still (xp) is related to x, as follows: Xp = How long will it take for X, to change from 0.3 to 0.35.

Answer: A swimming pool at 40°C is at a lower temperature than a cup of tea at 90°C. However, the swimming pool contains a lot more water. Therefore, the pool has more thermal energy than the cup of tea even though the tea is hotter than the water in the pool.

Explanation: Heat and Temperature do not mean the same thing. ... A swimming pool at 40°C is at a lower temperature than a cup of tea at 90°C. However, the swimming pool contains a lot more water. Therefore, the pool has more thermal energy than the cup of tea even though the tea is hotter than the water in the pool.

Answer:

Kinetic energy of boy just before hitting the ground is [tex]\approx[/tex]1000 J.

Speed of boy just before hitting the ground is 7.67 m/s

or 17.16 mi/hr.

Explanation:

Given that:

Mass of boy = 75lb = 34 kg

Height, h = 10ft = 3m

To find:

Kinetic energy of boy when he hits the ground.

As per law of conservation of energy The potential energy gets converted to kinetic energy.

[tex]\therefore[/tex] Kinetic energy at the time boy hits the ground = Initial potential energy of the boy when he was at the Height 'h'

The formula for potential energy is given as:

[tex]PE = mgh[/tex]

Where m is the mass

g is the acceleration due to gravity, g = 9.8 [tex]m/s^2[/tex]

h is the height of object

Putting all the values:

PE = [tex]34 \times 9.8 \times 3 \approx 1000\ J[/tex]

Hence, Kinetic energy is [tex]\approx[/tex]1000 J.

Formula for Kinetic energy is:

[tex]KE = \dfrac{1}{2}mv^2[/tex]

where m is the mass and

v is the speed

Putting the values and finding v:

[tex]1000 = \dfrac{1}{2}\times 34 \times v^2\\\Rightarrow v^2 = 58.82\\\Rightarrow v = 7.67\ m/s[/tex]

Given that:

1 m = 1.094 yd and 1 mi = 1760 yd

[tex]\Rightarrow 1609\ m = 1\ mi[/tex]

Converting 7.67 m/s to miles/hour:

[tex]\dfrac{7.67 \times 3600}{1609}=17.16\ mi/h[/tex]

Answer:

172.385 g/mol

Explanation:

Magnesium Tartrate is C4H4MgO6

C - 12.01 g/mol

H - 1.01 g/mol

Mg - 24.305 g/mol

O - 16.00 g/mol

12.01(4) + 1.01(4) + 24.305 + 16(6) = 172.385 g/mol

Answer:

172.38

Explanation:

[tex]C_4H_4MgO_6\\C=12.01\\H=1.01\\Mg=24.30\\O=16.00\\\\4(12.01)+4(1.01)+24.30+6(16.00)\\48.04+4.04+24.30+96\\=172.38[/tex]

C = 12.01

H=1.01

Mg=24.30

O =16.00

4(12.01)+4(1.01)+24.30+6(16.00)

48.04 +4.04+24.30+96

=172.38