What personal experiences have you had with watching a substance change from one phase to another?

In hydrogen, the transition from level 2 to level 1 has a rest wavelength of 121.6 nm.1).Find the speed for a star in which this

soldier1979 [14.2K]

Answer:

1). $v = - 2960526m/s$

2). Toward us

3). $v = - 493421m/s$

4). Toward us

5). $v = 1480263m/s$

6). Away from us

7). $v = 3207236m/s$

8). Away from us

Explanation:

Spectral lines will be shifted to the blue part of the spectrum if the source of the observed light is moving toward the observer, or to the red part of the spectrum when it is moving away from the observer (that is known as the Doppler effect).

The wavelength at rest is 121.6 nm ( $\lambda_{0} = 121.6nm$ )

$Redshift: \lambda_{measured} > \lambda_{0}$

$Blueshift: \lambda_{measured} < \lambda_{0}$

Then, for this particular case it is gotten:

Star 1: $\lambda_{measured} = 120.4nm$

Star 2: $\lambda_{measured} = 121.4nm$

Star 3: $\lambda_{measured} = 122.2nm$

Star 4: $\lambda_{measured} = 122.9nm$

Star 1:

$Blueshift: 120.4nm < 121.6nm$

Toward us

Star 2:

$Blueshift: 121.4nm < 121.6nm$

Toward us

Star 3:

$Redshift: 122.2nm > 121.6nm$

Away from us

Star 4:

$Redshift: 122.9nm > 121.6nm$

Away from us

Due to that shift the velocity of the star can be determine by means of Doppler velocity.

$v = c\frac{\Delta \lambda}{\lambda_{0}}$ (1)

Where $\Delta \lambda$ is the wavelength shift, $\lambda_{0}$ is the wavelength at rest, v is the velocity of the source and c is the speed of light.

$v = c(\frac{\lambda_{measured}- \lambda_{0}}{\lambda_{0}})$ (2)

Case for star 1 $\lambda_{measured} = 120.4 nm$ :

$v = (3x10^{8}m/s)(\frac{120.4nm-121.6nm}{121.6nm})$

$v = - 2960526m/s$

Notice that the negative velocity means that is approaching to the observer.

Case for star 2 $\lambda_{measured} = 121.4 nm$ :

$v = (3x10^{8}m/s)(\frac{121.4nm-121.6nm}{121.6nm})$

$v = - 493421m/s$

Case for star 3 $\lambda_{measured} = 122.2 nm$ :

$v = (3x10^{8}m/s)(\frac{122.2nm-121.6nm}{121.6nm})$

$v = 1480263m/s$

Case for star 4 $\lambda_{measured} = 122.9 nm$ :

$v = (3x10^{8}m/s)(\frac{122.9nm-121.6nm}{121.6nm})$

$v = 3207236m/s$

4 0

3 years ago

What best explains whether bromine (Br) or neon (Ne) is more likely to form a covalent bond? On left, a purple circle labeled Br

blondinia [14]

Answer:

I believe the answer is Bromine forms covalent bonds because it has many electron shells, but neon has only two electron shells and is tightly bound to its electrons.

Explanation:

valence electrons are the outermost shell, so when you go through keeping that in mind it helps you find the right answer

6 0

3 years ago

Which of the following statements are true?a. Earth's geographic south pole is also a magnetic south pole. b. Scientists have ev

ANTONII [103]

Answer:

c, d, and f.

Explanation:

Let us look at each of the statements one at a time:

a. Earth's geographic south pole is also a magnetic south pole.

This is not true. Earths magnetic south pole is slightly off (2,860 km away) from earth's geographical south pole.

b. Scientists have evidence that single isolated magnetic poles, called magnetic monopoles, exist.

Nope. So far no evidence yet exists that hypothetical magnetic monopoles exist.

c. The north pole of a bar magnet will attract the south pole of another bar magnet.

True, since opposite ends of a magnet attract and like ends repel.

d. The south poles of two bar magnets will repel each other.

Also true since like poles of a magnetic repel each other.

e. The north poles of two bar magnets will attract each other.

No, the north poles of two magnets will repel each other since they have the same polarity.

f. Earth's geographic north pole is actually a magnetic south pole.

Yes. If you call the point of the needle that points north the north pole of the compass, then it points north because it is attracted to the south pole of earth's magnetic field. (like repel opposites attract)

8 0

3 years ago

9. [03.03]

Evgen [1.6K]

Answer:

Circuit one will have more current than circuit two

Explanation:

I am assuming that you have to see which circuit has the greater current in this case. Well, this is the perfect example of Ohm's Law, which states the following -

V = IR,

where V = voltage / potential difference, I = current, and R = resistance

If one circuit has twice the voltage and half the resistance of the second circuit, as voltage is directly proportional to the resistance -

2V = I( 1 / 2R ),

4V = IR,

I = 4V / R

Whereas in the second circuit -

V = IR,

I = V / R

As you can note, voltage is directly proportional to the current ( I ) as well as the resistance. The only difference between the two formulas I = 4V / R, and I = V / R is the difference in the voltage. With the voltage being 4 times greater in the first circuit, and current is 4 times greater in the first circuit as well.

Hence, circuit one will have more current than circuit two

5 0

3 years ago

Read 2 more answers

Please help :<

Artemon [7]

Answer: methyl

Explanation:

7 0

2 years ago