An antimicrobial chemical was added to a population of bacteria. the initial population was 107 living cells (10,000,000). after 2 minutes, only 106 cells still remained alive. after another 2 minutes (4 minutes of total treatment), about how many cells would still be alive?

I believe after four minutes the population of the cells would be 10^5. Antimicrobial chemicals are those chemicals or agents that destroy or kill bacteria ad other pathogens. Therefore, addition of an antimicrobial chemical in a bacteria population triggers death of the cell, and since the rate of cell division is lower than the rate of death the number of cells reduces with time.According to te above information the population reduces by a factor of 10, thus if the initial population  was 10^7 after two minutes, the population was 10^6, which means after the next two minutes the population would be (10^6)/10 which gives 10^5

Mantle convection  is the slow  creepingmotion of earth's solid silicate  mantle  caused by  convection  currents carrying  heat from the interior  to the planet's surface.[1][2]  the earth's surface  lithosphere, which rides atop the  asthenosphere  (the two components of the  upper mantle), is divided into a number of  plates  that are continuously being created and consumed at their opposite  plate boundaries. accretion occurs as mantle is added to the growing edges of a plate, associated with  seafloor spreading. this hot added material cools down by  conduction  and  convection  of heat. at the consumption edges of the plate, the material has thermally contracted to become dense, and it sinks under its own weight in the process of  subduction  usually at an  ocean trench.[3]this subducted material sinks through the earth's interior. some subducted material appears to reach the lower mantle,[4]  while in other regions, this material is impeded from sinking further, possibly due to a phase transition from  spinel  to  silicate perovskiteand  magnesiowustite, an  endothermic reaction.[5]the subducted oceanic crust triggers  volcanism, although the basic mechanisms are varied. volcanism may occur due to processes that add buoyancy to partially melted mantle causing an upward flow due to a decrease in density of the partial melt.secondary forms of convection that may result in surface volcanism are postulated to occur as a consequence of intraplate extension[6]  and  mantle plumes.[7]it is because the mantle can convect that the  tectonic plates  are able to move around the earth's surface.[8]mantle convection seems to have been much more active during the  hadean  period, resulting in gravitational sorting of heavier molten  iron, and  nickel  elements and  sulphides  in the core, and lighter  silicate minerals  in the  mantle.

Swating at a bee and it stings

if, i suppose that a bee stings me swinging my hand away from a bee. then that if, i persist patient when a bee or wasp areas on your surface to investigate a scent or to take h2o and i secreting heavily, the bug ultimately will move of its personal agreement. if i don't need to set for it to disappear, lightly and gently wipe it off with a part of the paper.