Since silver and gold are both shiny, rare and do not corrode, they are ideal materials for making... what?
1 answer:
You might be interested in
Main advantages of DDT are the insecticide property and the knoledge about its chemical synthesis.
Explanation:
At that time in 1939 it was discovered that DDT have insecticide properties. It is a useful property because it allows inhibition of insects populations in large areas. Killing insects will reduce the diseases transmitted by them as typhus and malaria. More over you prevent the destruction of the agricultural crops by the harmful insects.
However the synthesis of the molecule was known way back in 1874. From that time it was plenty of time in which chemistry knowledge evolved so the synthesis at kilograms scale was implemented. High quantities of DDT molecule become available for the market so that in 1945 was available as agricultural insecticide.
It was discovered that DDT have bad effects for human health and also over time some insects developed resistance and their were not affected anymore by the molecule.
You may find the chemical structure of DDT in the attached figure.
Lean more:
about DDT
#learnwithBrainly
Answer:
a. The student performed the splint test incorrectly. He should of observed a popping sound when the splint was placed in the test tube.
Explanation:
It is given that a student performed an experiment where he dropped a nickel metal in to HCl solution. He observed the reaction and performed a splint test in the test tube that is filled with a gas which is formed while Nickle is dropped into the solution of HCl.
But the experiment that the student performed was incorrect. He must have observed the popping sound when the splint was placed in the test tube.
When the splint was added to the gas splint flared up. The hydrogen gas pops out when exposed to the flame.
Thus the correct option is (a).