1. |
1. Neutrons
are subatomic particles with a positive charge. |
2. |
2. The
atomic nucleus contains electrons and neutrons. |
3. |
3. All
atoms of the same element have the same number of protons. |
4. |
4. Protons
are more massive than neutrons. |
5. |
5. Protons
repel electrons because they have the same charge. |
6. |
6. All
electrons have a relative minus one charge. |
7. |
7. Electrons
repel electrons because they all have the same charge. |
8. |
8. Atomic
numbers are all whole numbers like 1, 2, etc. |
9. |
9. Mendeleev
proposed the forerunner of the modern periodic table |
10. |
10. Elements
in the same vertical group show similar properties. |
11. |
11. Horizontal
rows in the periodic table are called "periods". |
12. |
12. Elements
in the periodic table are arranged in order of increasing atomic number. |
13. |
13. Electrons
show magnetic character. |
14. |
14. Valence
electrons are electrons close to the nucleus of the atom. |
15. |
15. Chlorine
is an example of a metal. |
16. |
16. Sodium,
Na, is a p-block element. |
17. |
17. Isotopes
are atoms of the same element with different numbers of electrons. |
18. |
18. The
electron configuration for the six electrons in carbon is 1s22s22p2 |
19. |
19. The
lowest value for the quantum number "n" is zero, |
20. |
20. An
atom with the electron configuration 1s22s2 2p1
has one valence electron. |