1. The Hertzsprung-Russell diagram below shows how the brightness, surface temperature, and color of stars are related.stars would be
A. Barnard’s Star is less bright than the sun, has a surface temperature below 3,800 K, and is red.
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2. The Milky Way galaxy is described as a disk of stars orbiting a central point on the disk. Which of these best explains why people on Earth cannot see the entire shape of the Milky Way?
A. Earth is a part of this galaxy.
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3. A student learns that the sun is classified as a medium-size star and that many stars are much bigger and brighter. However, the student observes that other stars look very dim, even through a telescope.Why do other stars look much dimmer than the sun?
D. As light from other stars travels through space, it gets reflected.
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4. The sun is a mid-sized, main sequence star. What stage is next in the life cycle of the sun?
A. red giant
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5. In November 2013 an object orbiting the sun seemed to disappear behind the sun. When a satellite did not detect the object, astronomers thought that the object had been destroyed when it passed close to the sun. However, when another satellite detected a small, bright object with a fan-shaped tail, astronomers proposed that the object was not destroyed.What type of object were astronomers most likely observing?
A. A comet
Image result for why do gases exert pressure
The molecules are continually colliding with each other and with the walls of the container. When a molecule collides with the wall, they exert small force on the wall The pressure exerted by the gas is due to the sum of all these collision forces.The more particles that hit the walls, the higher the pressure.
Answer:
Neutrons- 9 Electrons- 8
Explanation:
Protons equals electrons and since the atomic# of oxygen is 8, 8 is the proton and 8 will be the electrons a s well since it isn't an ion. You subtract 8 from the 17 to get 9 as the neutron.
Answer: The entropy change of the surroundings will be -17.7 J/K mol.
Explanation: The enthalpy of vapourization for 1 mole of acetone is 31.3 kJ/mol
Amount of Acetone given = 10.8 g
Number of moles is calculated by using the formula:
Molar mass of acetone = 58 g/mol
Number of moles = 
If 1 mole of acetone has 32.3 kJ/mol of enthalpy, then
0.1862 moles will have = 
To calculate the entropy change for the system, we use the formula:
Temperature = 56.2°C = (273 + 56.2)K = 329.2K
Putting values in above equation, we get
(Conversion Factor: 1 kJ = 1000J)
At Boiling point, the liquid phase and gaseous phase of acetone are in equilibrium. Hence,
Answer:
The answer to your question is: 0.25 l
Explanation:
Data
P1 = 1 atm
V1 = 0.5 l
P2 =2 atm
V2 = ?
T = constant
Formula
V1P1 = V2P2
Clear V2 from the formula
V2 = V1P1/P2
Substitution
V2 = (0.5)(1)/2 substitution
= 0.25 l result
