For each of the following processes that show the formation of ions, complete the process by indicating the number of electrons that must be gained or lost
to form the ion. Indicate the total number of electrons in the ion, and in the atom from which it was
made.
a. Al S Al3 d. F S F
b. S S S2 e. Zn S Zn2
c. Cu S Cu f. P S P3
77. For each of the following atomic

Let AB be a chord of the given circle with centre and radius 13 cm.

Then, OA = 13 cm and ab = 10 cm

From O, draw OL⊥ AB

We know that the perpendicular from the centre of a circle to a chord bisects the chord.

∴ AL = ½AB = (½ × 10)cm = 5 cm

From the right △OLA, we have

OA² = OL² + AL²

==> OL² = OA² – AL²

==> [(13)² – (5)²] cm² = 144cm²

==> OL = √144cm = 12 cm

Hence, the distance of the chord from the centre is 12 cm.