The Structure of Atoms

1. How does a sodium atom, with an electron distribution of 2, 8, 1, achieve a more stable state?

• A) By gaining 7 electrons to fill the third orbit.
• B) By losing the single electron in its third orbit.
• C) By losing all 8 electrons from its second orbit.
• D) By gaining one proton in its nucleus.

2. The atomic number of an element is determined by the number of which particle in the atom's nucleus?

• A) Electrons
• B) Neutrons
• C) Protons
• D) Ions

3. An atom has an atomic number of 17 and a mass number of 35. How many neutrons does it contain?

• A) 17
• B) 52
• C) 35
• D) 18

4. A sodium atom has 11 protons and 12 neutrons. What is its mass number?

• A) 11
• B) 12
• C) 1
• D) 23

5. Why do different isotopes of the same element exhibit the same chemical properties?

• A) They have the same number of neutrons.
• B) They have the same mass number.
• C) They have the same number of protons and electrons.
• D) They are all equally stable.

6. According to the 2n² rule, what is the maximum number of electrons that can be held in the second orbit (n=2) of an atom?

• A) 2
• B) 8
• C) 18
• D) 32

7. What is a positively charged ion called?

• A) Anion
• B) Cation
• C) Isotope
• D) Molecule