Answer:
12.34 amu
Explanation:
Let the 1st isotope be A
Let the 2nd isotope be B
Let the 3rd isotope be C
From the question given above, the following data were obtained:
1st Isotope (A):
Mass of A = 12.32 amu
Abundance (A%) = 19.5%
2nd isotope (B):
Mass of B = 13.08 amu
Abundance (B%) = 26.23%
3rd isotope (C):
Mass of C = 11.99 amu
Abundance (C%) = 54.27%
Atomic mass of X =?
The atomic mass of the element X can be obtained as follow:
Atomic mass = [(Mass of A × A%)/100] + [(Mass of B × B%)/100] + [(Mass of C × C%)/100]
= [(12.32 × 19.5)/100] + [(13.08 × 26.23)/100] + [(11.99 × 54.27)/100]
= 2.402 + 3.431 + 6.507
= 12.34 amu
Thus, the atomic mass of the element X is 12.34 amu
Answer:
Size and Temperature or E & B
Explanation:
The heat is involved in the production of 5.0 mol of MgO is 180 Kj
calculation
2 Mg (s) +O2 → 2 MgO
From the equation above two moles of MgO is used therefore
72.3 is for 2 moles
that is 72.3 kj = 2moles
? = 5 moles
by cross multiplication
= 72.3 kj × 5/2 = 180 Kj
Answer:
25.)Intrusive rocks have a coarse grained texture. Extrusive Igneous Rocks: ... Quick cooling means that mineral crystals don't have much time to grow, so these rocks have a very fine-grained or even glassy texture. Hot gas bubbles are often trapped in the quenched lava, forming a bubbly, vesicular texture.
Explanation:
Answer:
k = -0.09165 years^(-1)
Explanation:
The exponential decay model of a radioactive isotope is generally given as;
A(t) = A_o(e^(kt))
Where;
A_o is quantity of isotope before decay, k is decay constant and A(t) is quantity after t years
We are given;
A_o = 5 kg
A(10) = 2kg
t = 10 years
Thus;
A(10) = 2 = 5(e^(10k))
Thus;
2 = 5(e^(10k))
2/5 = (e^(10k))
0.4 = (e^(10k))
In 0.4 = 10k
-0.9164 = 10k
k = -0.9164/10
k = -0.09165 years^(-1)
