3. Robert Hooke was the first person to observe cells. He observed these cells in (a) a piece of cork.
(b) a slice of honeycomb.
(c) human blood.
(d) plaque from his own teeth.

QUESTION:- Robert Hooke was the first person to observe cells. He observed these cells in

(a) a piece of cork.

(b) a slice of honeycomb.

(c) human blood.

(d) plaque from his own teeth.

ANSWER:- (a) a piece of cork.

The cell was first discovered and named by Robert Hooke in 1665. He remarked that it looked strangely similar to cellula or small rooms which monks inhabited, thus deriving the name. However what Hooke actually saw was the dead cell walls of plant cells (cork) as it appeared under the microscope.

when the volume of gas is   changed from   717.73 ml   to 852 ml   the temperature will   change   from 315   c to 452   c

    calculation

this is calculated using the charles law formula

that is,   v1/t1 = v2/t2

          v1=?

        t1 = 315 c   into   kelvin = 315 +273 = 588 k

        v2 = 852   ml

        t2 = 425c + 273 =698 k

make v1   the subject of the formula ( by   multiplying both side by t1)

  v1=( v2 xt1) / t2

v1= (852 ml   x 588 k)/ 698 k= 717.73 ml