In Science Class . .. Weeks of 1/16 and 1/23

5th Grade: Last week and this week, we've continued our study of evaporation. Students put the same amount of water in different sized containers (with different surface areas) and measured how much water evaporated over the weekend. We found that the containers with the most surface area (water spread out) had highest evaporation rates, while our tall, thin vials barely lost any water to evaporation. Next up, we'll be looking more closely at the atmosphere and water cycle.
Key questions:

• What did your group find out about evaporation? (Evaporation happens more quickly in areas with higher temperature and in containers with larger surface area)
• What process is the opposite of evaporation? (Evaporation is the process of a liquid changing phase to a gas. Condensation is the process of a gas turning to a liquid. Freezing is liquid to solid while melting is solid to liquid.)

4th Grade: Last week, we examined the mineral property of hardness. Student experimented and found that "harder" minerals can scratch softer ones. We scratched four minerals with our fingernail, an aluminum nail, and a paper clip. The hardest mineral, quartz, could not be scratched by any of the tools, while gypsum, the softest, could be scratched by all three tools. This week, we discussed the Mohs Hardness Scale, which ranks minerals on a scale of 1-10 based on their hardness. Gypsum was a "2" while quartz was a "7." Often times, gemstones like emeralds, rubies, etc are high up on the hardness scale. Diamonds are a "10."

• What minerals were softer? How did you know? (Gypsum and calcite were softest and could be scratched by at least 2 of the tools. Fluorite and quartz were harder and couldn't be easily scratched.)
  
• What mineral was the hardest? (Quartz was hardest and could not be scratched by anything. FYI, it's a "7" on the Mohs hardness scale.)
  
• As we look at the hardness scale, can a "3" scratch a "5" mineral? What about the other way around? (A "3" mineral cannot scratch a "5" mineral because a "5" is harder, but a "5" mineral can make a mark on a "3" mineral.