Radon-222 has a half life of 3.82 days. How much radon - 222 will remain after 11.46 days if you started with a 3.0 mg sample?

Hey there!

A half-life means after a certain amount of time, half of that substance will be gone/changed after that time.

There are 3 half lives in 11.46 days because 11.46 ÷ 3.82 = 3.

So, we divide the 3mg sample in half 3 times.

3 ÷ 2 = 1.5

1.5 ÷ 2 = 0.75

0.75 ÷ 2 = 0.375

There will be 0.375mg of radon-222 remaining after 11.46 days.

Hope this helps!

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.