Answer:<em> A transfer of electrons occurs when fluorine and calcium react to form an ionic compound. This is because calcium is in group two and so forms ions with a two positive charge. ... A pairs of shared electrons makes one covalent bond. The compound formed is known as a molecule***</em>
B.Mg(OH)2 (the active ingredient in milk of magnesia)
Hellium argon neon xenon krypton randon oxygen fluorine chlorine bromine
PH + pOH = 14 ⇒ pOH = 14 - pH
pOH = 14 - 2.5
pOH = 11.5
[H⁺] = 10^(-pH) = 10^(-2.5)
[H⁺] = 0.003 M
[OH⁻] = 10^(-pOH) = 10^(-11.5) = 3 × 10⁻¹² M
[OH⁻] = 3 × 10⁻¹² M
pH = 2.5 implies one significant digit
