Lyndon is investigating whether putting plastic on her windows will seal out cold winter drafts. she covers a window on the south side of her house with plastic and measures the inside temperature near the window. she also measures the inside temperature near a window without plastic on the north side of her house. the windows are the same size and design. why is this not an ideal controlled investigation?
a. the windows should be different sizes to introduce variation.
b. the drafts at each window may be different because the windows aren’t near each other.
c. temperature isn’t a good indicator of cold winter drafts.
d. outside temperature is a better indicator of cold winter drafts than inside temperature.
e. the type of plastic used in the investigation isn’t mentioned.

the answer is b. the drafts at each window  may be different because the windows aren't near each other

Answer is: B.The drafts at each window may be different because the windows aren’t near each other.

The two main variables in an experiment are the independent and dependent variable.

Dependent variable (in this example temperature) is the variable being tested and measured in a scientific experiment.

Dependent variables depend on the values of independent variables (in this example the draft). The dependent variables represent the output or outcome whose variation is being studied.

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.