Atomic Structure Quiz
Questions: 16 · 10 minutes
1. In a simplified atomic energy-level model, what happens when an electron absorbs the required amount of energy?
It enters the nucleus and becomes a proton
It loses its negative charge while remaining in place
It moves to a higher available energy level
It causes the atom's atomic number to increase
2. A neutral sodium atom has 11 electrons. Which shell distribution fits the simplified shell model?
2, 9
2, 8, 1
2, 7, 2
8, 2, 1
3. A neutral chlorine atom has the simplified electron distribution 2, 8, 7. How many valence electrons does it have?
7 valence electrons
8 valence electrons
17 valence electrons
2 valence electrons
4. In Rutherford's gold-foil experiment, a small fraction of alpha particles were deflected sharply. What did this support?
Atoms contain no significant empty space
Electrons are embedded evenly throughout a positively charged sphere
The nucleus occupies most of the atom's volume
Positive charge and most atomic mass are concentrated in a small nucleus
5. An atom has 19 protons and 20 neutrons. What is its mass number?
20
39
19
1
6. A neutral oxygen atom has atomic number 8. How many electrons does it have?
6 electrons
7 electrons
16 electrons
8 electrons
7. An ion contains 13 protons and 10 electrons. What is its overall charge?
A positive charge of three
A positive charge of one
A negative charge of three
No overall charge
8. Why can the atomic mass shown for an element on a periodic table be a decimal?
Individual protons have fractional charges
It is a weighted average based on the element's naturally occurring isotopes
Electron mass is rounded up and added to the nucleus
Atoms usually contain partial neutrons
9. A neutral magnesium atom has 12 electrons. After losing two electrons, what does it become?
A positively charged magnesium ion with 10 electrons
A negatively charged magnesium ion with 13 electrons
A negatively charged magnesium ion with 10 electrons
A neutral magnesium isotope with 12 electrons and two fewer neutrons
10. Which particles are found together in the nucleus of a typical atom?
Protons and neutrons
Electrons and neutrons
Protons and electrons
Electrons only
11. Which pair represents isotopes of the same element?
Sodium-23 and magnesium-24
Carbon-14 and nitrogen-14
Carbon-12 and carbon-14
Oxygen-16 and fluorine-19
12. A particle has 17 protons and 18 electrons. Which description is correct?
It is a neutral chlorine atom
It is a chlorine cation with a positive-one charge
It is a chlorine anion with a negative-one charge
It is an argon atom with no charge
13. Carbon-14 has 6 protons. How many neutrons are in its nucleus?
6 neutrons
8 neutrons
14 neutrons
7 neutrons
14. Which change would turn an atom into an atom of a different element?
Gaining one electron
Losing one electron
Changing its number of neutrons
Changing its number of protons
15. Isotopes of the same element differ in their number of which particle?
Valence shells
Protons
Neutrons
Nuclear charges
16. What does an element's atomic number represent?
The average number of particles in the nucleus
The total number of protons and neutrons in each atom
The number of neutrons in the element's most common isotope
The number of protons in each atom of the element