Questions

High frequency sound attacks the tympanic memberane and makes it defective. 120 decibles is too high a pitch to be heard and therefore it impairs the hearing ability.

The Bacteria that causes Food Borne illness are called Food Borne Pathogens. Most of the pathogens are mesophilic in nature, optimum temperature may be around 20-45 degree celsius. This range of temperatures is often called the "Danger Zone." Dry foods do not support the growth of bacteria.

In order to kill pathogenic bacteria you need temperatures above 74ºC. Temperature is the easiest factor to control in order to prevent bacterial growth.

Ostrich

Joseph F. Glidden - Father of Barbed Wire.

• Glidden was born in New York in 1812. He invented Barbed Wire in 1873 and was granted the patent on Nov. 24, 1874. After a three year battle over the patent, which he eventually won received a patent for the modern invention in 1874 after he made his own modifications to previous versions.

The halogens make up group 17 in the periodic table.

They are five elements:

Chlorine (Cl)

Fluorine (F)

Bromine (B)

Iodine (I)

Astatine (At).

But astatine is not purely halogen as it is radioactive.