CP Chemistry Chapter 10 – Electrons
Practice questions
1. How many electrons are there in the third shell of the atom with atomic number 23?
1) 3
2) 8
3) 10
4) 11
5) 13
2. How many electrons are there in the “p” orbitals of the last shell of silicon,
atomic number 14?
1) 1
2) 2
3) 3
4) 4
5) 0
3. Which of the following is the correct order for electrons filling in orbitals?
1) 1s, 2s, 2p, 2d
3) 3s, 3p, 4s, 3d
2) 2p, 3s, 3p, 3d
4) 3p, 4s, 3d, 5s
5) 4s, 3d, 4p, 4d
4. How many electrons are there in the “p’ orbitals of the last shell of potassium,
atomic number 19?
1) 1
2) 2
3) 3
4) 4
5) 0
5. The number of electrons in the highest energy level of
1) 2
2) 4
3) 5
4) 6
20Ca
is
5) 8
6. Which atom in the ground state has three unpaired electrons in its outermost principle
energy level?
l) 3Li
2) 13Al
3) 15P
4) 38Sr
7. The electron dot arrangement around an atom of sulfur is
1) four single dots
2) four pairs of dots
3) two single dots
4) three pair of dots
5) two single and two pair of dots
8. What is the electron dot arrangement for the element X if its electron configuration
is 1s2 2s22p3 ?
l ) one single dot
2) three single dots
3) three
single dots and one pair of dots
4) one single dot and three pair of dots
5) four
pair of dots
9. If “n” represents the number of any energy level energy, what is the most electrons that
any level can contain?
1) n
2) 2n
3) n2
4) 2n2
10. Since an atom is considered to be electrically neutral, the number of electrons is equal
to the number of 1) neutrons;
2) protons;
3) protons + neutrons;
4) protons - neutrons.
11. The characteristic light spectrum of an element is produced when
1) the energy level of the nucleus is increased
2) electrons drop back to lower energy levels
3) electrons are raised to higher energy levels
4) electrons are emitted by an atom
12. According to the quantum theory of light, the separate packets of energy by which
the light waves travel are called 1) molecules
2) protons;
3) ions
4) neutrons
5) photons
13. The relationship between the energy of an electron and the electron’s distance from
the nucleus is basically
1) the greater the energy the farther the electron is from the nucleus.
2) the greater the energy the closer the electron is to the nucleus.
3) the distance of the electron from the nucleus is unrelated to the electron’s energy.
4) electrons of all energies remain the same distance away from the nucleus
14. If “n” represents the number of any energy level, how many orbitals are in that
energy level?
1) n
2) 2n
3) n2
4) 2n2
15. The total number of electrons that can fill the “p” sublevel is
1) 3
2) 10
3) 6
4) 8
5) 14
16. Which energy level transition represents the greatest absorption of energy?
1) ls to 3p
2) 2p to 3s
3) 3s to 3p
4) 3s to 4s
17. Oxygen (atomic number 8) has how many electrons in the second energy level?
1) 2
2) 6
3) 7
4) 8
5) none of these
18. Which electron transition is accompanied by a release of energy?
1) 1s to 2s
2) 2s to 2p
3) 3p to 3s
4) 4p to 5s
19. The number of “p” electrons in the highest energy level of 16S is
1) 2
2) 3
3) 4
4) 6
5) 8
20. The number of orbital pairs of electrons in an atom with an electron configuration of
1s2 2s22p4 is
1) 1
2) 2
3) 3
4) 4
5) 5