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All 9 questions. After you submit, each question shows the right answer and why. Back to the quick check
Most of an atom's mass is packed into its tiny nucleus.
Which tiny particle in an atom has a negative charge?
In the gold-foil experiment, most alpha particles bounced back, which showed that atoms are solid all the way through.
An atom has 17 protons and 18 electrons. What kind of particle is it?
Potassium has 19 electrons. Using the shell model the Atom Builder draws, how are they arranged?
A chlorine atom has 17 protons and a mass number of 37. How many neutrons does it have?
An atom gives out light when one of its electrons drops from a higher energy level to a lower one.
Using diameters of about 10⁻¹⁰ m for an atom and 10⁻¹⁵ m for its nucleus, by roughly what factor is the atom's volume larger than the nucleus's volume? Give the power of ten as a single number (for example 6 for 10⁶).
Explain why the 'planetary' picture of electrons in fixed orbits is a misleading model of an atom, and what the quantum-mechanical model says instead.
