Answer:
20.2 amu.
Explanation:
Let A represent isotope ²⁰X
Let B represent isotope ²²X
From the question given above, the following data were obtained:
For Isotope A (²⁰X):
Mass of A = 20
Abundance (A%) = 90%
For Isotope B (²²X):
Mass of B = 22
Abundance (A%) = 10%
Relative atomic mass (RAM) =?
The relative atomic mass (RAM) of the element can be obtained as follow:
RAM = [(Mass of A × A%)/100] + [(Mass of B × B%)/100]
RAM = [(20 × 90)/100] + [(22 × 10)/100]
RAM = 18 + 2.2
RAM = 20.2 amu
Thus, relative atomic mass (RAM) of the element is 20.2 amu
Because despite being natural they still harm the ozone layer and cause breathing problems, even suffocation.
N = 3.2 moles, T = 50 + 273 = 323 K, P = 101.325 kPa, R = 8.314 L.kPa/K.mol
PV = nRT
V = nRT / P substituting.
V = (3.2 mole)(8.314 L.kPa/K.mol )(323 K) / (<span>101.325 kPa)
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Answer:
D. 0.75 grams
Explanation:
The data given on the iridium 182 are;
The half life of the iridium 182,
= 15 years
The mass of the sample of iridium, N₀ = 3 grams
The amount left, N(t) after two half lives is given as follows;

For two half lives, t = 2 × 
∴ t = 2 × 15 = 30


∴ The amount left, N(t) = 0.75 grams