It is a principle that states that mass cannot be loss or gained in a chemical reaction.
1) reactants: Ca + O2 (g)
2) Unbalanced equation: Ca + O2 (g) -> CaO
3) Balanced equation: 2Ca + O2 (g) -> 2CaO
That makes the Earth, the Sun, and the rest of the solar system
<span>something like 23 thousand times as old as the human species !
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Their is 2 valence electrons
Answer:
3.25×10²⁴ molecules
Explanation:
From the question given above, the following data were obtained:
Mass of H₂O = 97.2 g
Number of molecule of H₂O =?
From Avogadro's hypothesis, we understood that:
1 mole of H₂O = 6.02×10²³ molecules
Next, we shall determine the mass of 1 mole of H₂O. This can be obtained as follow:
1 mole of H₂O = (2×1) + 16
= 2 + 16
= 18 g
Thus,
18 g of H₂O = 6.02×10²³ molecules
Finally, we shall determine the number of molecules in 97.2 g of H₂O. This can be obtained as follow:
18 g of H₂O = 6.02×10²³ molecules
Therefore,
97.2 g of H₂O = 97.2 × 6.02×10²³ / 18
97.2 g of H₂O = 3.25×10²⁴ molecules
Thus, 97.2 g of H₂O contains 3.25×10²⁴ molecules.
