| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.70 |
| Score | 0% | 54% |
Convert -20C° to F°.
36 |
|
-4 |
|
-36 |
|
78 |
To convert from C° to F° use:
\(F° = {9 \over 5}C° + 32\)
\(F° = {9 \over 5}(-20) + 32\)
\(F° = {-180 \over 5} + 32\)
\(F° = -36 + 32 = -4\)
DNA is encoded through a combination of which of the following?
helix |
|
gametes |
|
genes |
|
nucleotides |
Deoxyribonucleic acid (DNA) is the molecule that contains genetic information. DNA is encoded through a combination of nucleotides that bind together in a specific double helix pattern.
Earth's history is divided into time periods, which of these is the shortest time period?
period |
|
eon |
|
age |
|
epoch |
The Earth is approximately 4.6 billion years old and its history is divided into time periods based on the events that took place and the forms of life that were dominant during those periods. The largest graduation of time is the eon and each eon is subdivided into eras, eras into periods, periods into epochs, and epochs into ages.
Which of the following would be used in eye glasses to correct farsightedness?
concave lens |
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convex mirror |
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convex lens |
|
concave mirror |
Unlike curved mirrors that operate on the principle of reflection, lenses utilize refraction. A convex lens is thicker in the middle than on the edges and converges light while a concave lens is thicker on the edges than in the middle and diffuses light. A common use for curved lenses is in eye glasses where a convex lens is used to correct farsightedness and a concave lens is used to correct nearsightedness.
A compound is a substance containing two or more different chemical elements bound together by what kind of bond?
molecular |
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ionic |
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covalent |
|
chemical |
A compound is a substance containing two or more different chemical elements bound together by a chemical bond. In covalent compounds, electrons are shared between atoms. In ionic compounds, one atom borrows an electron from another atom resulting in two ions (electrically charged atoms) of opposite polarities that then become bonded electrostatically.