<span>Fluorine ONLY form\s an ion with a -1 charge. The other three are metals, and metals for positively charged ions.</span>
The law of conservation of mass states that mass is neither created nor destroyed. Since we have 2 g/mol of A and 3 g/mol of B then AB should be equal to the sum of their molar mass that is
2 g/mol + 3 g/mol = 5 g/mol AB
for the case of A2B3
A2 = 2 * 2 = 4 g/mol
B3 = 3 * 3 = 9 g/mol
therefore A2B3 = 13 g/mol
The pH scale is used to measure how acidic or alkaline something is.
Hope that helped you!
BRAINLIEST??