Answer:
64.52 mg.
Explanation:
The following data were obtained from the question:
Half life (t½) = 1590 years
Initial amount (N₀) = 100 mg
Time (t) = 1000 years.
Final amount (N) =.?
Next, we shall determine the rate constant (K).
This is illustrated below:
Half life (t½) = 1590 years
Rate/decay constant (K) =?
K = 0.693 / t½
K = 0.693/1590
K = 4.36×10¯⁴ / year.
Finally, we shall determine the amount that will remain after 1000 years as follow:
Half life (t½) = 1590 years
Initial amount (N₀) = 100 mg
Time (t) = 1000 years.
Rate constant = 4.36×10¯⁴ / year.
Final amount (N) =.?
Log (N₀/N) = kt/2.3
Log (100/N) = 4.36×10¯⁴ × 1000/2.3
Log (100/N) = 0.436/2.3
Log (100/N) = 0.1896
Take the antilog
100/N = antilog (0.1896)
100/N = 1.55
Cross multiply
N x 1.55 = 100
Divide both side by 1.55
N = 100/1.55
N = 64.52 mg
Therefore, the amount that remained after 1000 years is 64.52 mg
A. Decomposing water requires a high activation energy.
Explanation:
In decomposing water to release hydrogen gas to make fuel cells, the process requires a very high activation energy.
2H₂O ⇆ 2H₂ + O₂
This is the overall reaction. O-H must be broken to release free hydrogen to produce hydrogen gas.
The O-H bond is a very strong force of attraction that requires a high activation energy to overcome.
- The activation energy is the energy barrier that must be overcome before a reaction takes place.
- The sun is a renewable source of energy.
- Water decomposition produces useful oxygen gas needed by all life for cellular respiration.
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<span>D. The screw changes the direction of a force - it converts linear force into rotational force. It also reduces the force required - the closer the threads, the smaller the input force required to get the same output force.</span>
Answer:
Kinetic energy increases.
Explanation:
In a solid, molecules do not have much room to move. They are very slow moving, which means that kinetic energy is low. In a liquid, molecules have more room to move. They are able to move faster than a solid, which means that kinetic energy is low.
From greatest to lowest kinetic energy:
gas, liquid, solid
Answer:
it's a trigonal bipyramidial
Explanation:
because NH3 have 3 hydrogen atoms
