To determine a planet's mass, astronomers typically measure the minuscule movement of the star caused by the gravitational tug of an orbiting planet. For planets the massof Earth detecting such a tiny tug is extraordinarily challenging with current technology
According to the balanced chemical equation:
4 HPO₃ + 12 C → 2 H₂ + 12 CO + P₄
4 moles of HPO₃ ---gives---> 12 moles of CO
2.73 moles of HPO₃ ---gives---> ? moles of CO
so number of moles of CO =

= 8.19 moles of CO
Number of molecules of CO = number of moles * Avogadro's number
= 8.19 * (6.022 * 10²³) = 4.93 * 10²⁴ molecules
Alkaline Earth Metals and Alkali Reactive metals because they need more electrons to acquire octet.
Phenolphthalein is an indicator used in chemistry to detect acidic or basic/alkaline solutions.It is often used in the lab as an indicator used to carry out accurate titration using soluble reactants.