The correct option is FLUORINE AND COPPER.
An ionic compound is usually formed by the combination of a metal and a non metal, the metal usually act as an electron donor while the non metal act as an electron acceptor. Thus, in ionic compounds, there is total transfer of electrons from the metal to the non metal. In the question given here, copper is the metal while the fluorine is the non metal.<span />
It is important because if the sample size is smaller, outliers could skew the data more than if it was large.
The mass of He gas = 21.428 g
<h3>Further explanation</h3>
Given
120 liters of He gas
Required
the mass in grams
Solution
Conditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure). At STP, Vm is 22.4 liters/mol.
Mol for 120 L :

Mass of He gas(MW=4 g/mol) :

Explanation:
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