Atoms and Molecules
What is the smallest chemical unit of matter?
Atom
What makes up air?
Bonus- give the percentage of each gas
Nitrogen- 78%
Oxygen- 21%
Other gases- 1%ish
If atmospheric pressure is exerted on all things, why don't we get crushed?
The air pressure inside your body counteracts the air pressure outside your body.
Why is water a liquid at room temperature, when other chemicals similar to water are gases at the same temperature?
Hydrogen bonding keeps water molecules close together and limits their movement somewhat. As a result, water is a liquid at room temperature when other chemically similar substances are gases.
What are the 3 main layers of the earth?
Crust, Mantle, Cord
What do we call it when 2 or more atoms link together to make a substance with unique properties?
Molecule
Suppose you left a glass of water outside on two different days. On the first day, it is warm and humid. On the second day, it is the same temperature, but the humidity is low. Each day, you measure how long it takes the water to completely evaporate from the glass. On which day will the times it takes the water to evaporate be the smallest?
The water will take the least time to evaporate on the second day. When humidity is high, there is already a lot of water vapor in the air. Thus, water vapor does not evaporate very quickly. On low humidity days, there is little water vapor in the air, so water evaporates quickly.
What are the two general layers of the atmosphere?
Bonus: Name the regions within the layers
Homosphere- ground level to 80km up
Troposphere, Stratosphere, Mesosphere
Heterosphere- 80km to 2,415km
Thermosphere, Exosphere
Why does solid water (ice) float, whereas many other solid substances would sink when placed in their liquid form?
What are the 3 types of rock?
Bonus: define how each is made
Sedimentary: chemical rxns cement sediments together, hardening them
Igneous: forms from molten rock (lava)
Metamorphic: igneous or sedimentary rock that has been changed as a result of great pressure or temperature (marble)
What do we call the quantity of a substance within a certain volume?
Concentration
Why do humans need oxygen??
Oxygen is necessary for combustion, which is the chemical reaction that supply energy for our bodies.
Does temperature measure heat? Explain.
No. Temperature is a measure of the energy of random motion in a substance's molecules. When the temperature is high, the molecules in the air colliding with your skin have much more energy than the molecules in your skin. As a result, energy is transferred from the air to you, which makes you hotter.
How much of earth's surface is covered in water, and what do we call the sum of all water on the planet?
71% is covered with water.
The hydrosphere is the sum of all water on a planet.
Name the 4 basic types of clouds.
Cumulus
Stratus
Cirrus
Lenticular
The chemical formula for baking soda is NaHCO3. How many atoms make up one molecule of baking soda?
6
What two major functions for the maintenance of life on earth does carbon dioxide play?
1. Through photosynthesis plants convert CO2 and H2O into glucose.
2. It helps regulate the temperature of the earth through the greenhouse effect. CO2 and other gases trap a large fraction of the light that the earth radiates, allowing that light to warm the atmosphere. Without this process, the earth would be lose too much heat, and not be able to support life.
What happens to temperature as altitude increases? Why?
Temperature decreases with altitude in the troposphere, increases in the stratosphere, and then decreases again in the mesosphere. Ozone gas is in the stratosphere, therefore there are more molecules bumping into each other in that area, increasing the temperature in that area.
What is the process by which water is continuously exchanged between earth's various water sources, and what are the steps in this process?
Hydrologic Cycle: evaporation, transpiration, condensation, precipitation, evaporation
Name 2 factors that influence an area's weather.
Water vapor in the atmosphere (condensation/precipitation)
Thermal energy (temperature)
Uneven distribution of thermal energy (winds/fronts)
Water does not dissolve gasoline. Is gasoline most likely made up of ionic, polar, or non-polar molecules? Why?
What is ozone?
Ozone is a molecule composed of three oxygen atoms, which makes a filter in the atmosphere. When the harmful ultraviolet light from the sun hits an ozone molecule, it is destroyed, so it does not reach the surface of the earth.
What do we see as a result of high-energy collisions between ionized particles in the ionosphere?
Bonus: How are these particles ionized?
The auroras are seen because these collisions involve a lot of energy, and some of that energy is converted to light.
Various types of radiation from the sun collide with the atoms in the ionosphere and rip some of the electrons away, which causes them to become electrically charged. When an atoms turns into an ion, we say that it has been ionized.
What are cloud condensation nuclei?
Small airborne particles upon which water vapor condenses to form clouds.
How are scientists reasonable certain that substances in the core of the earth are in motion?
The earth has a magnetic field that must be caused by the motion of electricity.