Question

directions: answer the following questions on the bubble form provided. completely fill in the circles. make sure to put your answers on the answer sheet. do not write on this exam. 1) based on this bohr model, what element is represented? a) silicon b) boron c) oxygen d) nitrogen 2) what is the energy level for the outermost electrons of a neutral zinc atom? a) 4 b) 3 c) 2 d) 5 3) when is a neutral atom most stable and least likely to bond with other atoms? a) when there are 3, 4 or 5 valence electrons b) when there are 8 valence electrons or a full valence shell c) when there are 1 or 2 valence electrons d) when there are 6 or 7 valence electrons 4) what is the name for the group of atoms that all have 7 valence electrons? a) noble gases b) alkali metals c) transition metals d) halogens 5) sodium and sulfur both have their valence electrons in the third energy level. what is the best explanation for why sulfur atoms have a smaller atomic radius than sodium atoms? a) sodium atoms have more core electrons to shield the positive charge from the nucleus b) sulfur atoms have more protons in the nucleus creating a larger positive pull on the outer electrons, pulling the outer ring in closer c) sodium atoms have fewer neutrons causing a weaker pull on the outer electrons d) outer electrons are attracted to each other so if there are more more the electrons will move closer together

Explanation:

Step1: Identify element from Bohr - Model

Count protons (equal to electrons in neutral atom). The Bohr - Model shows 7 electrons, so the element is Nitrogen.

Step2: Determine zinc's outermost energy level

Zinc (Zn) has atomic number 30. Its electron - configuration is [Ar] 3d¹⁰4s², so outermost electrons are in energy level 4.

Step3: Recall stable atom condition

Atoms are most stable with a full valence shell, usually 8 valence electrons (except for H and He).

Step4: Identify group with 7 valence electrons

Atoms with 7 valence electrons are in Group 17, known as Halogens.

Step5: Explain atomic radius difference

Sulfur has more protons than sodium. More protons mean a greater positive charge in the nucleus, pulling outer electrons closer and resulting in a smaller atomic radius.

Answer:

1. d) Nitrogen
2. a) 4
3. b) When there are 8 valence electrons or a full valence shell
4. d) Halogens
5. b) Sulfur atoms have more protons in the nucleus creating a larger positive pull on the outer electrons, pulling the outer ring in closer