Answer:
3 years
Explanation:
Given data:
Initial amount of sample = 160 Kg
Amount left after 12 years = 10 Kg
Half life = ?
Solution:
at time zero = 160 Kg
1st half life = 160/2 = 80 kg
2nd half life = 80/2 = 40 kg
3rd half life = 40 / 2 = 20 kg
4th half life = 20 / 2 = 10 kg
Half life:
HL = elapsed time / half life
12 years / 4 = 3 years
Yes it is a exothermic reaction.
Well when a particle of air is becomes heated it rises, right? So you could write some like you started off close to the earth (aka the troposphere) until you became heated then you started to rise and as you reached higher elevations you cooled down and you were recycled into cool air and you moved back down and became new fresh cool air until the next time you'll become heated and rise again to be recycled into fresh cool new air.
The solid form of a substance is usually more dense than its
liquid and gaseous forms. Similarly the liquid form is usually more dense than
the gaseous form. Ice floating in water is an exception that breaks the general
density rule. So option “A” is the correct option in regards to the given
question. In case of ice formation, actually the density of water decreases by
about 9%. This is the main reason behind ice floating in water. Pure water has
the maximum density at 4 degree centigrade.
