38.46g
Explanation:
Given parameters:
Mass of CaF₂ = 75.0g
Unknown:
Mass of calcium that can be recovered = ?
Solution:
This is a mass percentage problem and we need to solve it accordingly.
To solve this problem;
Find the molar mass of CaF₂
Find the ratio between the molar mass of Ca and that of CaF₂
Multiply by the given mass
Molar mass of CaF₂ = 40 + (2 x 19) = 78g/mol
Mass of calcium = 
x 75 = 38.46g
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Mass percentage brainly.com/question/8170905
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About 8.0 moles of methane.Number of moles = MassMolar mass.
And thus we get the quotient:
128.3⋅g16.04⋅g⋅mol−1=8.0⋅moles of methane.
Note that the expression is dimensionally consistent, we wanted an answer in moles, and the quotients gives, 1mol−1=11mol=mol as required.
There Are Three Types Of Plate Boundaries. Which choice is NOT a Type Of Plate Boundary?
Answer:C. Thrust
John Dalton's original atomic theory contained the following key ideas and the incorrect one is that elements are made of tiny indivisible particles called atoms and is denoted as option A.
<h3>What is Atom?</h3>
This is defined as the smallest unit of matter which forms a chemical element and Dalton proposed that it was indivisible which was later proved wrong.
It was later discovered that atom is made up of sub atomic particles such as proton, electron and neutron. This was therefore the reason why option A was chosen as the most appropriate choice.
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The options include:
A. elements are made of tiny indivisible particles called atoms
B. Atoms are unchanged in chemical reaction
C. Atoms can join together in whole number ratios to form compounds.
D. The atoms of each element are unique
