Juju.01) 5 geologic events a group of students designed an experiment in an ice rink to represent the solar system. the steps of the experiment are listed below. 5: geologic events 1. choose a student to represent the sun. the planets are represented by two tennis balls. 2. ask the student to hold the tennis balls in each palm and spin on the ice with arms stretched out. 3. ask the student to draw in the arms after about 10 spins. 4. observe the student's arms rotate faster when they are closer to the body. 05 geologic events enors) the experiment most likely demonstrates that (2 points) 07 discussion-based sessment/module planets exert gravitational force on the sun the sun exerts gravitational force on the planets 3.07 discussion-based ssessment speed of a planet depends on its distance from the sun new version available! (3.0.119) get it now submit 18.07: module exam description

part 1: the half-life of the element is 22 years.

part 2: it will take 132.02 year for the sample to decay from 308.0 g to 4.8125 g.

explanation:

part 1: there are two ways to determine the half life time.

first way: the half life time can be determined directly from its definition as it is the time required for the sample to decay to its half concentration.

from the data the initial concentration was 45.0 g and decayed to its half value (22.5 g) in 22.0 years.

second way: the radio active decay is considered first order reaction so we can use the laws of first order reactions.

k = (1/t) ln (a/a-x), where k is the rate constant of the reaction,

t is the time of the reaction

a is the initial concentration of the reactant

a-x is the remaining concentration at time (t)

a = 45.0 g the initial concentration at t = 0 year.

at t = 22 year, a-x = 22.5 g

then k = (1/22 year) ln (45.0 g/ 22.5 g) = 0.0315 year-1.

the half-life time (t1/2) = ln 2/ k = 0.693/ k =0.693/ 0.0315 = 22 years.

part 2:

using the same law k = (1/t) ln (a/a-x),

using the given data; a = 308.0 g and a-x = 4.8125 g and the calculated k from the part 1 (k = 0.0315 year-1)

t = (1/k) ln (a/a-x) = (1/0.0315) ln (308.0/ 4.8125) = 132.02 years