Brad's teacher dropped a whole box of metal tacks onto the floor. His teacher then shares with the class that they will participate in a design challenge. Brad's teacher explains the criteria and constraints for the design challenge. Each team is challenged to design a device to try to pick up as many of the tacks as possible. The design can contain only one magnet. Each team will get only one pass of their device over the tacks. The team that picks up the most tacks will win the design challenge. Brad's team has several ideas for a winning design. Evaluate who has the idea for the kind of magnet that will MOST LIKELY pick up the most tacks.
A) Mary thinks they should use a bar magnet.
B) Paul thinks they should use a ceramic magnet.
C) Michael thinks they should use an electromagnet.
D) Kelly thinks they should use a horseshoe magnet.

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-

a) the particles of the chair are strongly held together.

a saline water is fed to a reverse osmosis unit at flow rate o rotameter connected to reject (retentate) line reads 8 installed in reject and permeate line reads 15.2 milli siemens/cm and 300 micro siemens/com respectively.

28528289 29823282 8298232 39858