<span>A flashlight is an electric-powered light source; the light source is a light bulb or an LED. The electrical energy is converted into visible light. Flashlights can be hand-held or mounted to a platform. Light from a lighting, on the other hand, is formed by exciting electrons to a higher state. </span>
Answer:
A. There is more dissolved oxygen in colder waters than in warm water.
D. If ocean temperature rise, then the risk to the fish population increases.
Explanation:
Conclusion that can be drawn from the two facts stated above:
*Dissolved oxygen is essential nutrient for fish survival in their aquatic habitat.
*Dissolved oxygen would decrease as the temperature of aquatic habit rises, and vice versa.
*Fishes, therefore, would thrive best in colder waters than warmer waters.
The following are scenarios that can be explained by the facts given and conclusions arrived:
A. There is more dissolved oxygen in colder waters than in warm water (solubility of gases decreases with increase in temperature)
D. If ocean temperature rise, then the risk to the fish population increases (fishes will thrive best in colder waters where dissolved oxygen is readily available).
Answer:

Explanation:
The question will be easier to solve if we interpret it as, " How long will it take until one-fourth of a sample of the element remains,?"
The half-life of the element is the time it takes for half of it to decay.
After one half-life, half (50 %) of the original amount will remain.
After a second half-life, half of that amount (25 %) will remain, and so on.
We can construct a table as follows:

