Answer:

Explanation:
We are asked to find how much of a 40 gram sample remains after 12 years.
Iron-55 has a half-life of 3 years. Therefore, after 12 years, 4 half-lives have been completed.
- 12 years/3 years = 4 half-lives
Every time a half-life is completed, half of the sample's mass decays. Remember we start with a 40 gram sample.
- 1 half- life: 40 g / 2 = 20 g
- 2 half-lives: 20 g / 2= 10 g
- 3 half-lives: 10 g / 2 = 5 g
- 4 half-lives: 5 g / 2 = 2.5 g
There is also a formula that can be used to solve this problem.

Where A₀ is the initial amount, t is the time, and hl is the half-life.
We know 40 grams is the inital amount, 12 years is the time, and 3 years is the halflife.




After 12 years, <u>2.5 grams </u> of Iron-55 will remain.
The answer is A beacause it Hyphae<span> perform a variety of </span>functions<span> in fungi. They contain the cytoplasm or cell sap, including the nuclei containing genetic material. </span>Hyphae<span> absorb nutrients from the environment and transport them to other parts of the thallus (</span>fungus<span> body).</span>
Answer:
C. petals
Explanation:
A)fruits
B)sepals
C)petals
D)anthers
E)ovaries
<em>The part that will not be necessary in wind pollinated angiosperm is the petals .</em>
The petal is a part of flower that is usually colorful and primarily function by attaracting insect pollinators to the flower.
<u>Since wind pollinated angiosperms do not need to attract insect for pollination, they do not need the colorful petals. They rely on wind to carry their pollen from their anthers to their stigmas (pollination).</u>
Hence, the correct option is C.
I'm not sure if this is exactly correct, but to complete photosynthesis, plants need carbon dioxide and water. Usually sunlight as well. If you are supposed to be specific, you could put H2O. I hope I answered your question!