Question

which elements had complete outer shells? give the name and symbol for each. what do you notice about the location of these elements? 2. which elements had only one valence electron? give the name and symbol for each. what do you notice about location of these elements? 3. what do you notice about the number of valence electrons as you move from left to right across a row or period in the periodic table? (na →mg →al →si →p →s →cl →ar) 4. what do you notice about the number of energy levels or shells as you move down a group or column in the periodic table? (h → li → na) 5. write the name of each family at the top of the columns on your periodic table using the following information. alkali metals - 1 valence - electron alkaline earth metals - 2 valence electrons boron family - 3 valence electrons carbon family - 4 valence electrons nitrogen family - 5 valence electrons oxygen family - 6 valence electrons halides - 7 valence electrons noble gases - complete outer shells 6. what do you notice about the location of the elements in each family? 7. in what family would you classify hydrogen? explain your choice. 8. in what family would each of these elements be classified? krypton iodine tin cesium 9. predict the number of valence electrons for each element based on its location in the periodic table of elements. you will need to use the table in your textbook. barium = lead = bismuth = potassium =

Explanation:

Step1: Identify noble gases

Noble gases have complete outer - shells. The noble gases are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn).

Step2: Note their location

Noble gases are located in Group 18 of the periodic table.

Step3: Identify elements with one valence electron

Alkali metals have one valence electron. They include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr).

Step4: Note location of alkali metals

Alkali metals are located in Group 1 of the periodic table.

Step5: Analyze valence electrons across a period

As you move from left to right across a row (period) in the periodic table (e.g., from Na to Ar), the number of valence electrons increases by 1.

Step6: Analyze energy levels down a group

As you move down a group (column) in the periodic table (e.g., from H to Li to Na), the number of energy levels or shells increases by 1.

Step7: Classify hydrogen

Hydrogen can be considered in a class of its own, but it is sometimes placed in Group 1 (alkali metals) because it has 1 valence electron, or in Group 17 (halogens) because it can gain an electron to form a negative ion.

Step8: Classify elements

• Rubidium (Rb) is an alkali metal (Group 1).
• Iodine (I) is a halogen (Group 17).
• Tin (Sn) is a carbon - family element (Group 14).
• Cesium (Cs) is an alkali metal (Group 1).

Step9: Predict valence electrons

• Barium (Ba) is in Group 2, so it has 2 valence electrons.
• Lead (Pb) is in Group 14, so it has 4 valence electrons.
• Bismuth (Bi) is in Group 15, so it has 5 valence electrons.
• Potassium (K) is in Group 1, so it has 1 valence electron.

Answer:

1. Noble gases have complete outer - shells. Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), Radon (Rn). They are in Group 18.
2. Alkali metals have one valence electron. Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs), Francium (Fr). They are in Group 1.
3. The number of valence electrons increases by 1 as you move from left to right across a period.
4. The number of energy levels or shells increases by 1 as you move down a group.
5. Hydrogen can be placed in Group 1 or Group 17.
6. Rubidium - Alkali metals (Group 1); Iodine - Halogens (Group 17); Tin - Carbon family (Group 14); Cesium - Alkali metals (Group 1).
7. Barium - 2 valence electrons; Lead - 4 valence electrons; Bismuth - 5 valence electrons; Potassium - 1 valence electron.