1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
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
Determine the molecular formula of a compound with an empirical formula of NH2 and a formula mass of 32.06 amu
Lilit [14]
N2H4

<span>Each nitrogen weighs 14.01 and each H weighs 1.01. !4.01+14.01+1.01+1.01 = 32.06 (roughly) </span>

4 0
2 years ago
Read 2 more answers
What volume will be occupied by 33.0 grams of CO2 at 500 torr and 27 °C?
wlad13 [49]

Answer:

V = 27.98 L

Explanation:

Given data:

Mass of CO₂ = 33.0 g

Pressure = 500 torr

Temperature = 27°C

Volume occupied = ?

Solution:

Number of moles of CO₂:

Number of moles = mass/molar mass

Number of moles = 33.0 g/ 44 g/mol

Number of moles = 0.75 mol

Volume of CO₂:

PV = nRT

R = general gas constant = 0.0821 atm.L/ mol.K  

Now we will convert the temperature.

27+273 = 300 K

Pressure = 500 /760 = 0.66 atm

By putting values,

0.66 atm×V = 0.75 mol × 0.0821 atm.L/ mol.K  × 300 K

V = 18.47 atm.L/0.66 atm

V = 27.98 L

4 0
2 years ago
The density of a pure substance is its mass per unit volume. The density of cresol has been measured to be 1024 g/L . Calculate
Ierofanga [76]

Answer: The mass of 405 ml of cresol is 415 grams

Explanation:

Density is defined as the mass contained per unit volume.

Density=\frac{mass}{volume}

Given : Density of cresol = 1024 g/L

Volume of cresol = 405 ml = 0.405 L   ( 1L=1000ml)

Putting in the values we get:

1024g/L=\frac{mass}{0.405L}

mass=1024g/L\times 0.405L=415g

Thus mass of 405 ml of cresol is 415 grams

3 0
3 years ago
The ____ are new substances that are created following a chemical reaction. *
KonstantinChe [14]

Answer:

b

Explanation:

8 0
2 years ago
A 5 mL sample of an unknown liquid is placed into a 250 mL flask that has had all of the air removed. The pressure measured in t
Brrunno [24]

Answer:

See explanation below

Explanation:

In this case, we can use the Boyle's law. Assuming that the temperature of both trial remains constant, then:

P₁V₁ = P₂V₂    (1)

You should note that this expression is usable when you are dealing with gases. However, we can treat this unknown liquid as a gas, because all the air on the flask is removed, and we can assume that the liquid can behave like an ideal gas.

So using the above expression, we can solve for P₂:

P₂ = P₁V₁ / V₂    (2)

In this case, we already have the values of presures and volume, so replacing in this expression:

P₂ = 34.5 * 5 / 214

<h2>P₂ = 0.806 kPa</h2>

This should be the pressure of the liquid.

Hope this helps

8 0
2 years ago
Other questions:
  • Assume an object A mass of 36.240 g and it’s density is 5.40 g/mL. What is it’s volume
    8·1 answer
  • Question 8 of 10
    9·2 answers
  • Which of the following is an examples of pseudoscience
    15·1 answer
  • Calculate the mass of 2.50 mol of methanol.
    11·2 answers
  • iron will react with oxygen to produce Fe2O3. how many grams of Fe2O3 will he produced if 0.18 mil of Fe reacts?
    11·1 answer
  • What is the theoretical yield of cyclohexene (in grams) that could be formed from 0.105 moles of cyclohexanol and 0.0444 moles o
    6·1 answer
  • What are the four most important elements on earth?
    12·2 answers
  • In the reaction of 3NO2 + H2O + NO + 2HNO3, if 6.0 moles of NO2 are present how many moles of NO are produced?
    14·1 answer
  • 3Mg(OH), + 2АІСІ,<br> 3MgCI,<br> +<br> 2Al(OH),<br> I need this asap
    15·1 answer
  • the roof of a building is 0.2km^2. during a rainstorm, 5.5 cm of rain was measured to be sitting on the roof. what is the mass i
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!