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.
One natural disaster has the ability to wipe out large crops and buildings that were used to fuel Earth's economy. It can also lead to a lack of biodiversity of an area that experienced the disaster.
For example, a tsunami can destroy buildings and kill an abundance of wildlife.
I hope I helped!
According to Bronsted-Lowry acid concept
an acid is a that donate a proton" and a base is a "proton acceptor."so
will look for that molecule to which <span>H2O</span> "donates" H+to become <span>OH−</span>. so answer will be..
. <span>NH3+H2O→NH+4+O<span>H<span>−
so correct option is NH3
hope it helps</span></span></span>
If we had the same climate every minute of every hour tons of carbon would circulate the earth and climate change would make the polar ice caps melt from all the carbon around
