Since there are 23 days and 24 hours in each day, you multi-ply them and get 552 hours. Since each hours is 60 minutes, 552*60 is 33120 minutes. Since one minute is 60 seconds, 60*33120 is 1,987,200 seconds. Therefore, there are 1,987,200 seconds in 23 days.
Answer:

Explanation:
We can write the amount of mass of radon-222 left after a time t by using the equation:

where
is the initial mass
t is the time
is the half-life
Substituting t = 15.2 d in the formula, we find

Answer:
natural income
Explanation:
Living sustainably in the 21st century means coexisting with the nature. In other words, to live sustainably means to meet the needs of the human without affecting or degrading the mother nature.
In the context, living sustainably means to live from the natural income from the nature's gift to us, using their natural resources and not hurting them or exploiting them. They may be resources from the soil, plants, clean air, animals, nature's clean water,etc.