Sort the following molecules or ions into their proper three-dimensional molecular shapes. Drag the appropriate molecules or ions to their respective bins. 1. NBr3
2. SO2
3. SBr42+
4. SO42+
5. CF3Cl
A. Tetrahedral
B. Trigonal pyramidal
C. Bent
D. Linear
E. Trigonal planar

NBr3 - Trigonal pyramidal

SO2- Bent

SBr42+- Tetrahedral

SO42- Tetrahedral

CF3Cl - Tetrahedral

Explanation:

The shape of a molecule depends on the number of electron pairs on the valence shell of the central atom in the molecule. This is well captured in the valence shell electron poair repulsion theory.

The number of electron pairs on the outermost shell of the central atom in a molecule are called regions of electron density. According to this theory, these regions of electron density must be positioned as far apart from each other as possible to minimize repulsions between electron pairs.

This theory is the basis of the shapes of molecules shown in the answer. If a molecule has four regions of electron density, it could be trigonal pyramidal or tetrahedral in shape such as NBr3 and CF3Cl.

Note that, when deciding on the three dimensional geometry of a molecule, only the covalent bonds present are considered.

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.