Iowa CORE Curriculum: Key Concepts

In order to determine the (professed) most important science concepts in the Iowa CORE Curriculum, I check the Performance Standards. What does the state want 8th graders to be able to do?
The "High Performance Level" is evaluated as follows.

High Performance Level: Understands ideas related to Earth, the universe, and the life sciences. Understands ideas related to the physical sciences and often can demonstrate the skills of scientific inquiry.

• Distinguished: Understands ideas related to Earth, the universe, and the life sciences. Understands ideas related to the physical sciences and can demonstrate the skills of scientific inquiry. 

Wow. Thank you, Iowa. That was clear. Ok, I'm not being completely fair. That was a Performance Standard. Essential Concepts and Skills are clearer:

	Understand and apply knowledge of processes and changes on or in the earth’s land, oceans, and atmosphere.
The surface of the earth changes. Some changes are due to slow processes, such as erosion and weathering, and some changes are due to rapid processes such as landslides, volcanic eruptions, floods and earthquakes.

That's it? That's all I need to teach in grades three through five ?(Category: Earth & Space/ Subcategory: Land, oceans, atmosphere).
I am still adjusting to Iowa CORE. I can't help it. I'm used to Texas state standards, which are very detailed and probably closer to individual district or area curriculum guidelines in Iowa. So, I'm trying to re-order my thinking to "Thank you Iowa, for giving broad guidelines and allowing me flexibility" instead of "That's not enough information!"

Ahem. On to those Key Concepts
Primary Students (K-2) focus on observing and identifying big concepts. Not much analysis or evaluation going on yet, but understanding concepts and being able to regurgitate or represent their knowledge. This is not to say that K-2 students shouldn't engage in Inquiry. They still need the inquiry process to supplant prior "pre-conceptions" with new facts. Math used is mostly for measurement.-

3rd-5th grade students move forward to deeper processes and understanding that experiments can have different variables and different outcomes. Mathematics in science increase from measurements to equations.

Although I won't* be teaching Science to 6th-8th graders, I immediately notice a spike in vocabulary. Students are expected to know the terminology for processes and phenomena, not just understand how they work. (Although that is certainly a pre-requisite!)

*Yes, I know, never say never. I just mean "won't" based on my current endorsements and foreseeable future.