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stira [4]
3 years ago
7

Are blue stars young or old? How can you tell?.

Chemistry
1 answer:
andriy [413]3 years ago
4 0
Astronomers measure the brightness of stars using light-years. This means that the light we see now left in that years ago, traveling through space in that distance at kilometer per second.

A star is born, it radiates energy for a long time, toward the end it expands, it may or may not explode, and then it dies. It vary in sizes, masses and surface temperature range. The colors of stars reflect their surface temperature. Their relative brightness is expressed in a scale of six magnitudes. The brightest the stars are first-magnitude stars, while the dimmest are sixth-magnitude stars.
 
The lower the number, the brighter the star.

For example:
                      Star color                        Surface Temperature
                     Blue-white                         around 25 000 K & higher
                     white                                  around 10 000 K
                     yellow                                around 7 000 K
                     Red                                    around 5 000 K & lower

You might be interested in
Alcl3+Na =NaCl+ Al .did Al change oxidation number
saul85 [17]

Answer:

yes it is ( From +3 to 0 )

Explanation:

If this is the balanced equation:

AlCl3     +    3Na ——>    3NaCl      +      Al

Al      Cl        3Na             Na     Cl            Al

+3     -3        0                    +1       -1            0

5 0
4 years ago
Which statement describes what it means for a planet’s orbit to be elliptical?(1 point)
sesenic [268]

Using the concepts of ellipse and the universal law of gravitation it can be found that the correct answer is:

      a) The planet’s path around the sun is not a perfect circle and is shaped like an oval.

The universal gravitational law establishes that the force between two bodies is proportional to their mass and inversely proportional to the square of their distance, when one of the bodies has much greater mass than the other, the body with greater mass experiences less rotational acceleration.

In the case of the sun and the planet, the sun is many orders of magnitude more massive than the planets, therefore, it is almost fixed in the center and the lighter planets rotate around it, where the sun is in the focus of the ellipse orbit.

In the special case that the two foci coincide, there is a circular movement, but the most general is that there is some separation between the foci, so the movement is elliptical with the sun located in one of the foci.

Let's analyze the claims of this exercise

a) True. When the orbit is not a perfect circle, you have an elliptical orbit, this is the most common case.

b) False. The axis of the planet has no effect on the orbit, it affects the intensity of the radiation that reaches the planets

c) False. Circular motion is a special case of elliptical motion when the two foci coincide

d) False. The axis of the planet influences the intensity of radiation reaching the surface, but not the shape of the orbit of the plant.

Using the concepts of ellipse it can be found that the correct answer is:

      a) The planet’s path around the sun is not a perfect circle and is shaped like an oval.

learn more about planetary motion here:

brainly.com/question/4978861

3 0
3 years ago
Salt is dissolved in a flask of tap water. Distilling the mixture causes the salt to separate from the water. Which type of ener
Alik [6]
Heat energy is required.
In distillation, the solution is first heated, where heat energy is required, such as using a bunsen burner.
When the solution is heated, the water may reach its boiling point and evaporate. However, salt does not. When water molecules evaporates, it travels through a condenser that cools it down into liquid again. Therefore we get pure water. Salt is also obtained in the original beaker.
Therefore to first start this process, heat energy is required.
6 0
3 years ago
Read 2 more answers
Examination of the first few successive ionization energies for a given element usually reveals a large jump between two ionizat
gladu [14]

Answer:

See Explanation

Explanation:

Ionization energy refers to the energy required to remove an electron from an atom. Metals have lower ionization energy than non metals since ionization energy increases across a period.

One thing that we must have in mind is that it takes much more energy to remove an electron from an inner filled shell than it takes to remove an electron from an outermost incompletely filled shell.

Now let us consider the case of magnesium which has two outermost electrons. Between IE2 and IE3 we have now moved to an inner filled shell(IE3 refers to removal of electrons from the inner second shell) and a lot of energy is required to remove an electron from this inner filled shell, hence the jump.

For aluminium having three outermost electrons, there is a jump between IE3 and IE4 because IE4 deals with electron removal from a second inner filled shell and a lot of energy is involved in the process hence the jump.

Hence a jump occurs each time electrons are removed from an inner filled shell.

7 0
3 years ago
Conditions for an experimental chemistry reaction require a temperature of 300 K. The temperature in the lab is 55 F. Which of t
OLga [1]
The suggested answers are for K=298 degrees and the nearest correct answer seems to be increase the room temperature by 22 degrees Fahrenheit. But by calculation, for 300 K, then convert 300k to degrees Celsius = 300-273.15=26.85 degrees celsius. Then convert the 26.85 to degrees F, so F=9/5C + 32= 48.33+32=80.33-55F (present room temperature)=25.33 degrees F to increase the room temperature by.


6 0
3 years ago
Read 2 more answers
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