Oh For God Sake Please Can any Super Genius Or a top Contributor Answer These Question.?

Question

Its my 3 time I am asking This question. In other words I lost 15 POINTS.

*How Are the size of nanoparticles different from the normal sized particle of titanium oxide?

*Suggest how the size of nanoparticles might help them to enter the body more easily?

*And any 2 advantages of using nanoparticles in Sun creams?

(If you likeYou may answer each question in Just a Few SENTENCES)

Answer 1

heres a thought, do your own homework!!!!

Answer 2

I HATE BIOLOGY!!!

Answer 3

Nanoparticles, which are less than 100 nanometers in size, have long been familiar as by-products of combustion or constituents of air pollution; but increasingly, researchers are designing and synthesizing ultrasmall particles to take advantage of their novel properties. Most toxicologists agree that nanoparticles are neither uniformly dangerous nor uniformly safe, but that the chemical and physical properties that make them potentially valuable may also make their toxicities differ from those of the same materials in bulk form.

One of the reasons for concern about nanoparticles' toxicity has to do with simple physics. For instance, as a particle shrinks, the ratio of its surface area to its mass rises. A material that's seemingly inert in bulk thus has a larger surface area as a collection of nanoparticles, which can lead to greater reactivity. For certain applications, this is an advantage; but it can also mean greater toxicity. "The normal measure of toxicity is the mass of the toxin, but with nanomaterials, you need a whole different set of metrics," says Vicki Colvin, a professor of chemistry at Rice University in Houston and a leading expert on nanomaterials.

Beyond the question of increased reactivity, the sheer tininess of nanoparticles is itself a cause for concern. Toxicologists have known for years that relatively small particles could create health problems when inhaled. Researchers have found evidence that the smaller particles are, the more easily they can get past the mucus membranes in the nose and bronchial tubes to lodge in the alveoli, the tiny sacs in the lungs where carbon dioxide in the blood is exchanged for oxygen. In the alveoli, the particles face the white-cell scavengers known as macrophages, which engulf them and clear them from the body. But at high doses, the particles overload the clearance mechanisms.

It is the potential growth, however, of technologies involving precisely engineered nanoparticles, such as buckyballs and their near cousins, carbon nanotubes, and the use of these new materials in consumer products that has made the question of toxicity particularly urgent.

In addition to questions about how easily nanoparticles can penetrate the body, there is also debate over where they could end up once inside. Günter Oberdörster, a toxicologist at the University of Rochester, found that various kinds of carbon nanoparticles, averaging 30 to 35 nanometers in diameter, could enter the olfactory nerve in rodents and climb all the way up to the brain. "There is a possibility that because of their small size, nanoparticles can reach sites in the body that large particles cannot, cross barriers, and react," says Oberdörster.

Answer 4

* Nanoparticles are more spherical in shape and readily overlap. This is due to less conglomeration. They are much smaller in size, on the micron level.

* Spherical nature and small size means easier entrance to pores and membranes, as well as inhalation. They are not as likely to create an obstruction. Since they can enter the body more easily, especially inhalation, they are a greater toxicological concern.

* Small size means thinner coatings and thus more transparency then standard sized creams.

* Smaller size also means they can be more closely compacted in a film and thus offer higher UV blocking.

Answer 5

Ok then. it would help you alot if you researched your own homework.  Then you could answer the questions yourself and enjoy taking the credit for having done it.