Stars and the Universe
Name the 5 stages in the life of a medium-sized star in order.
nebula, protostar, star, red giant, white dwarf
What did Aristotle believe that "all matter" was made of?
List 3 properties of metals.
2. Good conductors
3. Flexible (malleable and ductile)
Condensation is when a gas changes to a liquid. Evaporation is when a liquid changes to a gas.
suspension
How do stars make energy?
They fuse hydrogen atoms into helium ones.
How do atoms link together to form a molecule?
They share their electrons.
List 3 properties of nonmetals.
1. Dull
2. Good insulators (poor conductors)
3. Brittle
What is sublimation? Give an example of a substance that does this at standard temperature and pressure.
It's when a solid turns directly into a gas. Dry ice (frozen CO2) does this at standard temperature and pressure.
A colloid; ex: smoke, fog, mayonnaise, etc...
How do really large stars end their lives?
Most carbon atoms have 6 protons, 6 neutrons and 6 electrons. What is the atomic number of carbon? How do you know?
How can you describe the properties of metalloids?
They have properties between metals and nonmetals. Ex: They conduct electricity better than nonmetals but not as well as metals.
Thermal expansion is when substances increase in volume due to added heat.
Thermal contraction is when substances decrease in volume when heat is removed.
What is a homogeneous mixture involving a metal and another solid (usually another metal)? Give an example of one of these.
An alloy; ex: steel (iron + carbon), brass (copper +zinc)
What color are the hottest stars? How about the coolest ones?
Hottest - blue
Coolest - Red
It's about 12. You can find this by adding the protons and neutrons.
Give an example of how we'd use each of the following elements:
- aluminum
- argon
- boron
Aluminum - mirrors and food wrapping
Argon - Used in electric lighting
Boron - Used in the construction of aircraft
What usually happens to a substance's density when it freezes? How is water unusual in this regard?
Usually, when a substance freezes, it becomes more dense. However, when water freezes, the molecules spread farther apart and it becomes less dense.
Makadoo is a cook working in a restaurant. The chef asks her to make a sugar water solution. After tasting the solution, the chef tells her that it should be more concentrated. How can Makadoo make it more concentrated?
Makadoo can simply add more of the solute (sugar). If necessary, she can heat the solvent to get more sugar to dissolve.
How does a medium-sized star, like our Sun, end its life?
As a white dwarf
How is the periodic table organized? (there are 2 parts to this answer)
The elements are ordered from lowest atomic number to highest. Elements in the same column have similar properties.
Give an example of how we'd use each of the following elements:
- chlorine
- silicon
- copper
- silicon - used to make computer chips
- copper - used in electrical wiring
How are evaporation and boiling similar? How are they different?
Similarity - They both involve a liquid changing to a gas.
Differences - Evaporation is the slow change from a liquid to gas at temps below the boiling point. It happens only on the surface of a liquid.
Boiling happens at the boiling point, and the change occurs all throughout the water sample.
Professor Makadoo has a solution of 2 liquids that have different boiling points. What method can she use to separate them?
Professor Makadoo can use distillation to separate them.