I think the answer is C respiratory system
We can balance like the following:
<span>In NaBr both the oxidation states are +1 and -1 respectively.After the reaction Na reduced to Na+ and Br- oxidised to Br2.So NaBr is a redox reaction,not a decomposition reaction.</span>
I think the correct answer from the choices listed above is option 3. The atomic mass of an element is defined as the weighted average mass of that element's naturally occurring isotopes. <span>The atomic mass of a single atom is simply its total mass and is typically expressed in atomic mass units or amu.</span>
Answer: 1 mole ➡️ 6.022×10²³ atoms of si.
X mole ➡️ 2.8×10²⁴ atoms of si.
X = 2.8×10×10²³/6.022×10²³
= 28/6.022
= 4.65 moles.
Explanation: