<span>There are pros and cons as to whether CCA-treated (pressure-treated) wood should be removed from existing structures, and both sides are subjective.
Some of the arguments for leaving it include:
*When burned, the wood can release dangerous, and sometimes, lethal fumes.
*If buried in a landfill, the chemicals can soak into the ground and eventually contaminate ground water.
*Removing it can expose people to arsenic
*It is costly to remove an existing infrastructure that may or may not be harming people
*Studies conducted within the past decade have determined structures containing CCA-treated wood pose no hazard
*Studies also concluded that children who played on CCA-treated playgrounds were exposed to arsenic levels lower than those that naturally occur in drinking water
Some of the arguments for removing it include:
*The EPA determined that some children could face higher cancer risks from exposure to CCA-treated wood
*If removed, it will need to be disposed of and, as discussed above, that creates another set of problems that could affect a community's health.
A possible solution is to leave existing CCA-treated wood in place but seek viable, safe alternatives for future structures.</span>
Answer:
From Top to Bottom:
- Democritus coming up with the concept of an atom
- Dalton discovering that atoms are the smallest part of an element
- Rutherford discovering the nucleus of an atom
- Thomson discovering electrons
- Bohr modeling electrons orbiting the nucleus
- Schrodinger modeling electrons in the electron cloud
Explanation:
The best way to think about this is from the inside out. Democrats (who lived long before any of the other scientists mentioned) was the one who thought of the idea of the atom. - Therefore, this must be first because all other choices are elaborations on the idea that atoms exist. Next must be Dalton. Dalton saw atoms as "cannonballs" if you will; a solid mass. So then after that, Rutherford and his gold foil experiment (he discovered that some rays he shot through gold foil were deflected back; ie the existence of concentrated areas in an atom, ie the nucleus). Then we get into the information on electrons. We must start with discovery (Thomson). Heres where it gets complicated. Electrons don't <em>actually </em>orbit the nucleus, they exist in electron clouds. So it would be Bohr, who came up with the idea that electron exist outside the nucleus, then Schrodinger, who elaborated on Bohr's theory. Hope this helps!
Nat, Junior
Accel + AP Chem student
Answer:
4. Principal and Azimuthal (subsidiary) quantum number
5.Principal, Azimuthal (subsidiary), and magnetic quantum number
6. 10 electrons
7. 32 electrons
8. 36 electrons
Explanation:
4. Principal and Azimuthal (subsidiary) quantum number because in 4d, 4 represent principal quantum number and d- represents azimuthal quantum number (having l- value as 3)
5.Principal, Azimuthal (subsidiary), and magnetic quantum number are the first three because 2 stands for principal, s-for azimuthal (l=0) and magnetic quantum number for s- orbital= 0
6. 10 electrons, because for sublevel with l= 3, is a d-sub-level, and d- can take 10-electrons
7. 32 electrons, using the relationship 2×n^2 for the maximum number of electrons in a shell,
,n= 4 , hence 2×4^2= 32
8. 36 electrons, because n=4 and n= 3 can have the maximum configuration of [Ar]4s^2 3d^10 4p^6
This will sum up to 36- electrons, since Argon has 18 -electrons.
18+2+10+6=36 electrons
Answer:
I think it will option D hope it helps
Evaporation happens<span> when atoms or </span>molecules<span> escape from the liquid and turn into a vapor. Not all of the </span>molecules in a liquid have the same energy. <span>Sometimes a </span>liquid<span> can be sitting in one place (maybe a puddle) and its molecules will become a </span>gas<span>. That's the process called </span>evaporation<span>. It can happen when liquids are cold or when they are warm. It happens more often with warmer liquids. You probably remember that when matter has a higher temperature, the molecules have a higher </span>energy<span>. When the energy in specific molecules reaches a certain level, they can have a </span>phase change<span>. Evaporation is all about the energy in individual molecules, not about the average energy of a system. The average energy can be low and the evaporation still continues. </span>
