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.
Answer: D. Insects
Fossils that are preserved in the Burgess Shale are mostly the remains of soft-bodied organisms.
So the answer is D because insects don’t really have bones like the rest of the other options. They have exoskeletons which protects their organs and gives them support for moving around.
The heat of formation of nitrogen (II) oxide : +91.3 kJ/mol
<h3>Further explanation</h3>
Given
Reaction
N2(g) + O2(g) + 182.6 kJ → 2 NO(g)
Required
The heat of formation
Solution
In the above reaction, the heat of the reaction is located on the reactant side which indicates that the formation of nitric oxide requires heat (endothermic reaction).
In the above reaction the heat required to form 2 moles of NO, so the heat required for each mole is:
+182.6 kJ : 2 = =+91.3 kJ/mol
Answer:
Percent composition by element
Element Symbol # of Atoms
Hydrogen H 5
Carbon C 3
Nitrogen N 3
Oxygen O 9