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2 years ago

For communication to take place, there has to be:

Physics

1 answer:

aliya0001 [1]2 years ago

6 0

Communication can be anything that transmits a message.

Answer: <span>A. transmission of the message. </span>

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Which is a charcharacteristic of all ions?

ankoles [38]

An ion is created by the transfer of electrons. The metals give away the elections and become positively charged. The non - metals take on electrons.

Balance.

So an ion is any atom that either gives away or takes on electrons.

8 0

2 years ago

The following table lists the work functions of a few common metals, measured in electron volts. Metal Φ(eV) Cesium 1.9 Potassiu

Citrus2011 [14]

A. Lithium

The equation for the photoelectric effect is:

$E=\phi + K$

where

$E=\frac{hc}{\lambda}$ is the energy of the incident light, with h being the Planck constant, c being the speed of light, and $\lambda$ being the wavelength

$\phi$ is the work function of the metal (the minimum energy needed to extract one photoelectron from the surface of the metal)

K is the maximum kinetic energy of the photoelectron

In this problem, we have

$\lambda=190 nm=1.9\cdot 10^{-7}m$ , so the energy of the incident light is

$E=\frac{hc}{\lambda}=\frac{(6.63\cdot 10^{-34}Js)(3\cdot 10^8 m/s)}{1.9\cdot 10^{-7} m}=1.05\cdot 10^{-18}J$

Converting in electronvolts,

$E=\frac{1.05\cdot 10^{-18}J}{1.6\cdot 10^{-19} J/eV}=6.5 eV$

Since the electrons are emitted from the surface with a maximum kinetic energy of

K = 4.0 eV

The work function of this metal is

$\phi = E-K=6.5 eV-4.0 eV=2.5 eV$

So, the metal is Lithium.

B. cesium, potassium, sodium

The wavelength of green light is

$\lambda=510 nm=5.1\cdot 10^{-7} m$

So its energy is

$E=\frac{hc}{\lambda}=\frac{(6.63\cdot 10^{-34}Js)(3\cdot 10^8 m/s)}{5.1\cdot 10^{-7} m}=3.9\cdot 10^{-19}J$

Converting in electronvolts,

$E=\frac{3.9\cdot 10^{-19}J}{1.6\cdot 10^{-19} J/eV}=2.4 eV$

So, all the metals that have work function smaller than this value will be able to emit photoelectrons, so:

Cesium

Potassium

Sodium

C. 4.9 eV

In this case, we have

- Copper work function: $\phi = 4.5 eV$

- Maximum kinetic energy of the emitted electrons: K = 2.7 eV

So, the energy of the incident light is

$E=\phi+K=4.5 eV+2.7 eV=7.2 eV$

Then the copper is replaced with sodium, which has work function of

$\phi = 2.3 eV$

So, if the same light shine on sodium, then the maximum kinetic energy of the emitted electrons will be

$K=E-\phi = 7.2 eV-2.3 eV=4.9 eV$

7 0

3 years ago

Which relations below regarding magnetic field and electric field lines are true? 1. Magnetic field lines never begin nor end bu

Vlad1618 [11]

Answer:

Options 1 and 5 are correct

Explanation:

Magnetic field lines can never cross, the field is unique at any point in space. Magnetic field lines are continuous, forming closed loops without beginning or end. They go from the north pole to the south pole.

Magnetic field lines form closed loops but do not intersect.

Electric field lines originate at the positive charges and terminate at the negative charges. They move in a straight line and are parallel. Electric field lines neither form closed loops nor intersect.

Since, magnetic field lines form closed loops and move from North to South pole, they come out of north poles outside the magnet and into north poles inside the magnet, they also go into south poles outside the magnet and out of south poles inside the magnet.

3 0

3 years ago

Which is an example of someone responding from a personal perspective?

Anika [276]

Answer:

Explanation:

If Ami is saying she likes it then it it personal. If you are speaking from statistics and studies it is impersonal and technically not from there perspective. All of these do this except C.

5 0

2 years ago

Read 2 more answers

Please help ASAP <3 thanks

Vlad [161]

1.false
2.true
3.true
4.true
5.false/not entirely sure
6.true

7 0

2 years ago

Read 2 more answers