General Science Questions

Potentially hazardous foods are foods that might contain food poisoning bacteria and are capable of supporting growth of these bacteria or formation of toxins to levels that are unsafe for consumers, if the foods are not stored at correct temperatures. Toxins are poisonous chemicals produced by some types of bacteria.

The food can be left at room temperature until it reaches 60 deg C because food-poisoning bacteria will not multiply at 60 deg C or above. However, do not leave food cooling at room temperature unless you are sure that the temperature of the food is still at least above 60 C.

PTH - Parathyroid hormone which balances calcium levels if they are low.

A microscope is an instrument that magnifies objects. Cells that were first observed by Robert Hooke in the year 1665 in the compound microscope.

Molten rock inside the earth is called Magma.