B. Calculate your mass by converting your weight to kilograms. One pound equals approxi- mately 0.45 kilograms, so if you multiply your weight in pounds by 0.45, you will find your
mass in kilograms.
c. Convert your weight into grams by moving the decimal point three places to the right.
(Your mass in grams will be a much larger number than your weight in kilograms because
there are 1,000 grams in 1 kilogram.)
. Assuming that one newton is about the weight of 100 grams on Earth, how many newtons
of downward force do you exert on Earth?
Since the moon's gravity is about one-sixth of Earth's gravity, what would you weigh on the
moon? State your weight in pounds. (Hint: you have to multiply your weight by ;-)

58 km per hour : d

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

have a great day because if you dont you and i will be sad

може ли да зареждате повече информация, моля