The answer is c. number of protons and d. atomic number. The proton number can identify an element. And also the atomic number is equal to the number of protons.
Answer:
a. 0.119mol Kr
Explanation:
To solve this problem, we must understand that;
Mass = number of moles x molar mass
Molar mass of Kr = 83.3g/mol
Ar = 40g/mol
He = 4g/mol
Ne = 20.18g/mol
a0.119 mol Kr mass = 0.119 x 83.3 = 9.9g
b 0.400 mol Ar mass = 0.4 x 40 = 16g
C 1.25 mol He mass = 1.25 x 4 = 5g
d 2.02 mol Ne mass = 2.02 x 20.18 = 40.8
Krypton is the answer
There will be 7.5 g of Be-11 remaining after 28 s.
If 14 s = 1 half-life, 28 s = 2 half-lives.
After the first half-life, ½ of the Be-11 (15 g) will disappear, and 15 g will remain.
After the second half-life, ½ of the 15 g (7.5 g) will disappear, and 7.5 g will remain.
In symbols,
<em>N</em> = <em>N</em>₀(½)^<em>n</em>
where
<em>n</em> = the number of half-lives
<em>N</em>₀ = the original amount
<em>N</em> = the amount remaining after <em>n</em> half-lives
Answer:
n = Initial volume/22.4L
Explanation:
The molar concept is simply one that is used to find the Number of moles and explain the relationship it has with avogadro's number, molecular mass, molar mass e.t.c.
Now, in terms of molar mass, number of moles is given by the formula;
n = mass of the sample/molar mass
In terms of avogadro's number, number of moles is;
1 mole = avogadro's number = 6.02 × 10^(23)
Now, when dealing with ideal gases, the molar volume of an ideal gas is 22.4 L.
Now the relationship between this volume and the mole concept is that the number of moles is gotten by dividing the initial volume by this molar volume.
Thus;
n = Initial volume/22.4L
