Ddt, dde, pcbs and pbdes are all , dde, pcbs and pbdes are all biodegradable and do not persist in the environment btoxic at the organism level but not at the ecosystem level c teratogens non-biodegradable and subject to bioaccumulation and/or bioamplification dapproved for use as pesticides by the epa

The answer is non-biodegradable and subject to bioaccumulation and/or bioamplification.

DDT () is persistent, non-degradable insecticide and organic pollutant readily accumulated to soils and consequently affects organisms.
DDE () is non-degradable pesticide toxic to birds at the first place.
PCBs (polychlorinated biphenyls) are non-degradable organic compounds  very toxic to the environment.
PBDEs (polybrominated diphenyl ethers) are non-degradable compounds very toxic to environment, even able to affect brains of animals in the development period.

Heat is involved in chemical change in two ways; chemical changes either result in heat being added to or removed from an object, and chemical changes require a certain amount of heat before they can take place.

First up write the aim
then write the materials reqd.
then the procedure which you follow
then observation
then conclusion
then you can write lab safety rules or precautions(you can avoid if u want).
lemme' give an example
aim: to observe the double displacement reaction
materials reqd: bacl2 and na2so4, test tubes and a dropper
procedure:
1. take bacl2 in a test tube and na2so4 in the other.
2. then pour bacl2 into na2so4 solution.
3. observe
observation:
you will see that a white precipitate is formed called baso4. along with that common salt or nacl is formed.
the equation is
bacl2+na2so4=baso4+2nacl
conclusion:
a double displacement reaction is observed.
hope it