Answer:
2.765amu is the contribution of the X-19 isotope to the weighted average
Explanation:
The average molar mass is defined as the sum of the molar mass of each isotope times its abundance. For the unknown element X that has 2 isotopes the weighted average is defined as:
X = Mass X-19 * Abundance X-19 + MassX-21 * Abundance X-21
The contribution of the X-19 isotope is its mass (19.00 amu) times its abundance (14.55% = 0.1455). That is:
19.00amu * 0.1455 =
2.765amu is the contribution of the X-19 isotope to the weighted average
The total number of ions in 38.1 g of SrF₂ is 5.479 x 10²³.
<h3>What are ions?</h3>
Ions are the elements with a charge on them. It happens when they share electrons with other atoms to form a compound.
We have to calculate the total number of ions in 38.1 g of .
The molar mass of SrF₂ = 125.62 g/mol
The number of moles = 38.1 g of 1.0 mol / 125.62 = 0.30329 moles
Given that, total moles of SrF₂ ions in = 1.0 mol of + 2.0 moles of = 3.0 moles
Total moles of ions in 0.30329 moles of
= (0.30329 moles of SrF₂) x 3.0 / 1.0 = 0.90988 mol ions
We know that,
1.0 mole of ions = 6.023 x 10²³ ions
Thus, the number of total ions = ( 0.90988 mol ions) x 6.023 x 10²³ / 1.0 mol = 5.479 x 10²³ ions
Thus, the number of ions is in 38.1 g of 5.479 x 10²³ ions
To learn more about ions, refer to the link:
brainly.com/question/14295820
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The answer should be false. Elements contain only one atom.
Here is the answer for the three of them
<span>N20 = 16 e-
</span><span>SeCl2 =20
</span><span>PBr3 = 26
Remember that t</span><span>o find the valence electrons in an atom you need to identify what group the element is in. An element in group 1A has 1 valence electron. If the element is in group 2A, then it has two valence electrons.</span>
