Answer:(1) 6 sodium ions
(2)The movement of iodide ions occurs in the same direction as the sodium ions.
Explanation: Sodium-iodide symporter actively transports 2 sodium ions together with one iodide ions across the basement membrane into the thyroid follicular cells.(therefore for production of a single molecule of T3 3×2=6 sodium ions)This system utilises the concentration of sodium ions so that iodide ions can move against its concentration gradient.
Neutron or neutral and electran are positive
Conc = moles / Vol you have C but need to find moles
moles KCl = mass / molar mass
25 g / 74.55 g,p;
0.335 moles
So rearrange the formula to find volume. Vol = moles / Conc
0.335 moles / 0.750 mol / L = 0.447 L or 447 mL
The answer in this question is 447 mL.