11.66
A carbon atom, with a half-full outer shell of electrons - four in a shell that can hold eight - readily shares its electrons with other atoms and forms a vast number of molecules, many of which are the organic molecules that form the bulk of living matter. Looking at the periodic table in the Study Area, what other element do you think might play a role like carbon in life forms on some other planet?
Essay answers are limited to about 500 words (3800 characters maximum, including spaces).
11.58
The atoms that constitute your body are mostly empty space, and structures such as the chair you're sitting on are composed of atoms that are also mostly empty space. So why don't you fall through the chair?
Essay answers are limited to about 500 words (3800 characters maximum, including spaces)
12.40
Your friend says that the primary difference between a solid and a liquid is the kind of atoms in the material. Do you agree or disagree, and why?
Essay answers are limited to about 500 words (3800 characters maximum, including spaces).
12.46
What happens to the density of water when it freezes to become ice?
Essay answers are limited to about 500 words (3800 characters maximum, including spaces).
12.64
Why is it easier to start a fire with kindling rather than with large sticks and logs of the same kind of wood?
Essay answers are limited to about 500 words (3800 characters maximum, including spaces).
13.54
Why is blood pressure measured in the upper arm, at the elevation of your heart?
Essay answers are limited to about 500 words (3800 characters maximum, including spaces).
14.55
When an air bubble rises in water, what happens to its mass, volume, and density?
Essay answers are limited to about 500 words (3800 characters maximum, including spaces).
14.100 Two identical balloons of the same volume are pumped up with air to more than atmospheric pressure and suspended on the ends of a stick that is horizontally balanced. One of the balloons is then punctured. Is the balance of the stick upset? If so, which way does it tip?
(Figure 1)
Essay answers are limited to about 500 words (3800 characters maximum, including spaces).
11.42
Your friend says that what makes one element distinct from another is the number of electrons about the atomic nucleus. Do you agree wholeheartedly, partially, or not at all? Explain.
Essay answers are limited to about 500 words (3800 characters maximum, including spaces).
