The dot and cross diagram shows that a water molecule is made up of one oxygen atom joined to two hydrogen atoms, so the formula of water is H 2 O. A nitrogen molecule is made up of two nitrogen ...

(Image: NASA) Quantum dots have found applications in composites, solar cells (Grätzel cells) and fluorescent biological labels (for example to trace a biological molecule) which use both the small ...

Quantum dots are crystals of a fluorescent semiconductor material with a diameter of as few as 10 to 100 atoms (2-10 nm). They are used as labels for imaging molecules because of their very narrow ...