A radioactive substance loses its mass at a rate of 12% every second. At the beginning of an experiment, the substance has a mass of 6 cg. Which of the following equations best models the exponential function of this situation?

A. 3.60 cg
B. 0.72 cg
C. 3.17 cg
D. 0 cg
E. 5.28 cg

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.

answer: both chords and diameters have two endpoints on a circle. diameters must intersect the center of a circle.