Answer:
Astronomers use a number of telescopes sensitive to different parts of the electromagnetic spectrum to study objects in space. Even though all light is fundamentally the same thing, the way that astronomers observe light depends on the portion of the spectrum they wish to study.
Explanation:
Answer: The correct answer would be : "A bottle that is sealed".
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2. it becomes a liquid
4. its molecules lose energy
The change in state is due to the loss of energy.
Answer:
18.0 g H₂O
Explanation:
To find the mass of water (H₂O), you need to (1) convert grams O₂ to moles O₂ (via the molar mass), then (2) convert moles O₂ to moles H₂O (via mole-to-mole ratio from equation coefficients), and then (3) convert moles H₂O to grams H₂O (via the molar mass). It is important to arrange the conversions in a way that allows for the cancellation of units. The final answer should have 3 sig figs to match the sig figs of the given value.
Molar Mass (O₂): 2(15.998 g/mol)
Molar Mass (O₂): 31.996 g/mol
Molar Mass (H₂O): 2(1.008 g/mol) + 15.998 g/mol
Molar Mass (H₂O): 18.014 g/mol
2 H₂ + 1 O₂ -----> 2 H₂O
16.0 g O₂ 1 mole 2 moles H₂O 18.014 g
--------------- x ---------------- x --------------------- x ----------------- = 18.0 g H₂O
31.996 g 1 mole O₂ 1 mole
