5 moles of H2
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Natural selection is the process in which a weaker, or less advantaged animal loses something to a stronger, more advantaged animal. For example, a frog with a broken leg probably will not get to mate while a healthy frog will. Evolution is the process of an animal gradually changing over the generations biologically. An example of this is the theory that humans slowly evolved from monkeys, gradually becoming more and more human like.
Answer:
After the transfer the pressure inside the 20 L vessel is 0.6 atm.
Explanation:
Considering O2 as an ideal gas, it is at an initial state (1) with V1 = 3L and P1 = 4 atm. And a final state (2) with V2 = 20L. The temperature remain constant at all the process, thus here applies the Boyle-Mariotte law. This law establishes that at a constant temperature an ideal gas the relationship between pressure and volume remain constant at all time:

Therefore, for this problem the step by step explanation is:

Clearing P2 and replacing

Answer:
The atmosphere traps heat energy from the Sun and energy radiated from Earth's surface helping to maintain Earth's climate
Explanation:
Earth's atmosphere keeps much of the Sun's energy from escaping into space. This process, called the greenhouse effect, keeps the planet warm enough for life to exist. The atmosphere allows about half of the Sun's heat energy (50%) to reach Earth's surface.
The moles of oxygen gas (O2) that is needed is 4 moles
Explanation
2H2 +O2 → 2H2O
The moles of O2 is determined using the mole ratio of H2:O2
that is from equation above H2:O2 is 2:1
If the moles of H2 is 8 moles therefore the moles of O2
= 8 moles x 1/2 = 4 moles