For each pair of gases, select the one that most likely has the highest rate of effusion. Use the periodic table if necessary.Oxygen (O2) or hydrogen (H2):

By Graham’s law, a gas with a lower molar mass effuses faster. Hydrogen gas (H₂) has a molar mass of about 2 g/mol, compared with about 32 g/mol for oxygen gas (O₂), so hydrogen effuses faster.

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