Answer:
The answer is below
Explanation:
The half life of a substance is the time required by that substance to reduce to half of its initial value. The half life is calculated using the formula:

Given that t = 87 years, half life = 29 years, therefore the quantity of strontium-90 left is:

That is one-eight of Strontium 90 would be left after 87 years
Answer:
D
Explanation:
Additional classes of steroids include:
Neurosteroids such as DHEA and allopregnanolone
Aminosteroid neuromuscular blocking agents such as pancuronium bromide
Answer:
The Nervous System
The basic workings of the nervous system depend a lot on tiny cells called neurons. The brain has billions of them, and they have many specialized jobs. For example, sensory neurons send information from the eyes, ears, nose, tongue, and skin to the brain.
Explanation:
Hope It Help
The only living thing that makes its own food is the plant. So the first step in a food chain is always a plant that makes its own food by sun. :)))
I hope this is helpful
have a nice day