<span>The last option.
Plants absorb carbon dioxide from the atmosphere, water from the soil and other nutrients also from the soil - salts containing nitrogene, potassium, sulphur, etc. They use water and carbon dioxide to produce sugar through photosyntesis.
Decomposition is the reaction that converts any organic compound back into inorganic compounds - water, carbon dioxide and salts containing nitrogene, potassium, sulphur, etc. So it's basically the opposite.
So photosyntesis uses carbon dioxide as a reactive and take it from the atmosphere, whereas decomposition generates carbon dioxide as a product and releases it to the atmosphere.</span>
Answer:
(a) 
(b) 15 hours
Explanation:
half life, T = 12 hours
No = 19 g
(a) Let N be the amount remaining after time t.
Let λ be the decay constant.

The equation of radioactivity used here is given by


(b) N = 8 gram
Substitute the values in above equation

λ = 0.0577 per hour
So, 

Take natural log on both the sides
- 0.0577 t = - 0.865
t = 15 hours
Answer:
Fundamental quantities are the base quantities of a unit system, and they are defined independent of the other...
• Derived quantities are based on fundamental quantities, and they can be given in terms of fundamental quantities.
• In SI units, derived units are often given names of people such as Newton and Joule.
Explanation:
Answer:1) the total distance is the sum of the two distances
60 km + 45 km = 105 km
2) The displacement is the net movement, or the difference between the initial position and the final position
Call x the initial position, then the final position is x + [60km - 45km]
And the displacement is x + (60km - 45km) - x =60km -45 km = 15 km
Explanation:
It's true charged particles are always acted on by an electric field.when the velocity of the electron is parallel to the magnetic field, the magnetic force vanishes.