Answer:
a.Archaeopteryx
b.Archaeopteryx had more in common with other small Mesozoic dinosaurs than with modern birds.Archaeopteryx was generally accepted by palaeontologists and popular reference books as the oldest known bird.Archaeopteryx could grow to about 0.5 m (1 ft 8 in) in length.
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Answer:
B
Explanation:
Recall the law of effusion:

Because 5 mol of oxygen was effused in 10 seconds, the rate is 0.5 mol/s.
Let the rate of oxygen be <em>r</em>₁ and the rate of hydrogen be <em>r</em>₂.
The molecular weight of oxygen gas is 32.00 g/mol and the molecular weight of hydrogen gas is 2.02 g/mol.
Substitute and solve for <em>r</em>₂:

Because there are 5 moles of hydrogen gas:

In conclusion, it will take about 2.5 seconds for the hydrogen gas to effuse.
Check: Because hydrogen gas is lighter than oxygen gas, we expect that hydrogen gas will effuse quicker than oxygen gas.
Answer:
See explaination
Explanation:
Please kindly check attachment for the step by step solution of the given problem.
Answer:
The first is the empirical formula which shows you the number of different atoms in the compound. After you convert the grams of each element into moles, you calculate the ratio of the moles, which gives you the ratio of the elements in the compound. More number-crunching gives you the molecular formula.
Answer:
Atom is a the smallest particle of a chemical element that can exist.
Molecules is a a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.
Particles is a minute portion of matter.
A particle can be a single atom or a molecule ( a group of atoms held together by chemical bonds).