Which one of the following is the value of one nanometer?
- A.10⁻⁷ cm
- B.10⁻⁶ cm
- C.10⁻⁴ cm
- D.10⁻³ cm
Correct answer
Explanation
The correct answer is A, 10⁻⁷ cm. One nanometre is 10⁻⁹ metre, and since one metre is 100 (10²) centimetres, it equals 10⁻⁷ centimetre.
The prefix nano means one billionth. So 1 nm = 10⁻⁹ m = 10⁻⁹ × 10² cm = 10⁻⁷ cm. The nanometre is the natural unit for very small things: visible light has wavelengths of about 400 to 700 nm, and nanotechnology deals with materials from about 1 to 100 nm in size. One nanometre is also ten angstroms, since an angstrom is 10⁻¹⁰ m.
B is wrong: 10⁻⁶ cm is 10⁻⁸ m, which is ten nanometres.
C is wrong: 10⁻⁴ cm is 10⁻⁶ m, which is one micrometre (micron), a thousand nanometres.
D is wrong: 10⁻³ cm is 10⁻⁵ m, which is ten micrometres.
Exam tip: milli 10⁻³, micro 10⁻⁶, nano 10⁻⁹, pico 10⁻¹² of a metre; to convert metres to centimetres, add 2 to the power.
Practice Questions
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- B.diploid zygote
- C.non-motile male gametes
- D.motile male gametes
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- A.One
- B.Two
- C.Three
- D.Four
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- B.CₙH₂ₙ₋₂
- C.CₙH₂ₙ₊₁
- D.CₙH₂ₙ₋₁
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- B.Malaria
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- A.N-m
- B.N/m
- C.N-m²
- D.N/m²
Show answer
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Read the full explanation →