We’re being asked to **determine the mass of one CdSe quantum dot** given that it has a **diameter of 6.5 nm** and a **density of 5.82 g/cm ^{3}**.

Recall that ** density** is the ratio of the mass and volume of an object:

$\overline{){\mathbf{density}}{\mathbf{=}}\frac{\mathbf{mass}}{\mathbf{volume}}}$

Also, the ** volume of a sphere** is given by:

$\overline{){\mathbf{V}}{\mathbf{=}}\frac{\mathbf{4}}{\mathbf{3}}{{\mathbf{\pi r}}}^{{\mathbf{3}}}}$

where:

**r** = radius. Recall that diameter = 2r.

Very small semiconductor crystals composed of approximately 1000 to 100,000 atoms, are called quantum dots. Quantum dots made of the semiconductor CdSe are now being used in electronic reader and tablet displays because they emit light efficiently and in multiple colors depending on dot size. The density of CdSe is 5.82 g/cm^{3}.

What is the mass of one 6.5-nm CdSe quantum dot?

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Density concept. You can view video lessons to learn Density. Or if you need more Density practice, you can also practice Density practice problems.

What professor is this problem relevant for?

Based on our data, we think this problem is relevant for Professor West's class at UGA.