Answer:
a fossil
Explanation:
Petrified wood is a fossil. It forms when plant material is buried by sediment and protected from decay due to oxygen and organisms. Then, groundwater rich in dissolved solids flows through the sediment, replacing the original plant material with silica, calcite, pyrite, or another inorganic material such as opal.
The correct answer is the fourth option. The nervous system is the system in the body which can be affected by ionizing radiation. Exposure to this kind of radiation may lead to changes in motor function or neurological disorders.
Answer:
there will be more miles of reactants
Answer: False
Explanation: The chemical hazard label indicates the class of harzard of chemical products. It appears on their Safety Data Sheet (SDS), which contains a lot of informations about these substances.
The chemical hazard label is divided into four colors and which one has a meaning (categorie) connected with a number, like:
Blue: Health hazard - If the chemical is deadly (4), extreme danger (3), hazardous (2), slightly hazardous (1) or a normal material (0).
Red: Fire hazard (flammability) - If the chemical has flash point bellow 73ºF (4), bellow 100ºF (3), above 100ºF not exceeding 200ºF (2), above 200ºF (1) or will not burn (0).
Yellow: Reactivity (it can be related to instability) - If the chemical may detonate (4), shock and heat may detonete it (3), if it can suffer a violent chemical change (2) or unstable if heated (1) or if it is stable (0).
White: Specific hazard - If the chemical is acid (ACID) or alkali (ALK), for example.
