What are the properties of metal, nonmetal, and mellaloids

Metals: generally shiny, malleable, and hard. They are good conductors of electricity.

Non-metal: do not conduct heat or electricity very well. Are typically brittle and are not easily mold into shapes.

Metalloids: share characteristics of both metals and non-metals and are also called semimetals. Metalloids are typically semi-conductors, which means that they both insulate and conduct electricity. This semi-conducting property makes Metalloids very useful as a computer chip material. 

Radon-222 or rn-222 has a half-life of 3.82 days. to determine the fraction of an original sample of rn-222 that remains unchanged after 7.646 days, we calculate the amount of rn-222 remaining after 7.646 days and divide it with the original amount. using 1 gram as a basis and using half-life calculation methods, we can determine that  0.249 or 0.25  grams of rn-222 will remain, and thus the fraction remaining is 0.25 or 1/4.