Read the false statement. Atoms of elements with one valence electron form anions in order to meet the octet rule. Which answer
choice rewords the false statement so it is true? a. Atoms of elements with three valence electrons do not form ions because they meet the octet rule.
b. Atoms of elements with five to seven valence electrons form cations in order to meet the octet rule.
c. Atoms of elements with five to seven valence electrons form anions in order to meet the octet rule.
d. Atoms of elements with one valence electron gain seven electrons in order to meet the octet rule.
C. Atoms of elements with five to seven valence electrons form anions in order to meet the octet rule.
Explanation:
Atoms of elements gain or lose electron(s) to obey the octet rule by forming cations or anions.
Atoms with 1 to 3 valence electrons lose electrons to form cations in order to attain a stable configuration.
Atoms with 5 to 7 valence electrons gain electron(s) to form anions in order to attain stable configuration.
However, atoms with 8 valence electrons do not require to gain or lose electrons since they an octet configuration.
Atoms of metallic elements such as those in group 1 and 2 lose electron(s) to form cations while atoms of non-metallic elements such as halogens require to gain electron(s) to form anions so as to obey the octet rule.
Half-life is defined as the amount of time it takes a given quantity to decrease to half of its initial value. The equation to describe the decay is Nt=N0(1/2) where N0 is the initial quantity, Nt is the remaining quantity after time t, t1/2 is the half-time. So work out the equation, t1/2 = t (-ln2)/ln(Nt/N0) = 11.5*(-ln2)/ln(12.5/100) = 3.83 days
At the equivalence point, equal amounts of H+ and OH– ions will combine to form H2O, resulting in a pH of 7.0 (neutral). The pH at the equivalence point for this titration will always be 7.0, note that this is true only for titrations of strong acid with strong base.
where N0 is the initial quantity, Nt is the remaining quantity after time t, t1/2 is the half-time. So work out the equation, t1/2 = t (-ln2)/ln(Nt/N0) = 11.5*(-ln2)/ln(12.5/100) = 3.83 days