Question

1. determine the elements group number and number of valence electrons (# of electrons in the outermost shell). 1. fluorine 2. phosphorus 3. calcium 4. nitrogen 5. strontium 6. argon 7. potassium 8. helium 9. magnesium 10. sulfur 11. lithium 12. francium 13. carbon 14. iodine 15. oxygen 16. barium 17. aluminum 18. hydrogen 19. xenon 20. sulfur 21. what are valence electrons used for by an element? 22. which elements listed above want to lose electrons? 23. which elements above want to gain electrons? 24. why do the elements from question 22 want to lose electrons? why do the elements from question 23 want to gain electrons? (the answer is the same for both questions).

Explanation:

Step1: Recall valence - electron rules

Elements want to achieve a stable electron configuration like noble - gases. Metals tend to lose electrons and non - metals tend to gain electrons.

Step2: Analyze each element

• Fluorine (F) has 7 valence electrons and gains 1 electron to achieve a stable octet (8 electrons in the outer shell).
• Phosphorus (P) has 5 valence electrons and can gain 3 electrons to achieve an octet.
• Calcium (Ca) has 2 valence electrons and loses 2 electrons to achieve a stable configuration.
• Nitrogen (N) has 5 valence electrons and can gain 3 electrons to achieve an octet.
• Strontium (Sr) has 2 valence electrons and loses 2 electrons to achieve a stable configuration.
• Argon (Ar) is a noble gas with 8 valence electrons and is already stable.
• Potassium (K) has 1 valence electron and loses 1 electron to achieve a stable configuration.
• Helium (He) is a noble gas with 2 valence electrons and is already stable.
• Magnesium (Mg) has 2 valence electrons and loses 2 electrons to achieve a stable configuration.
• Sulfur (S) has 6 valence electrons and can gain 2 electrons to achieve an octet.
• Hydrogen (H) has 1 valence electron and can gain 1 electron to achieve a stable configuration (2 electrons like He).
• Aluminum (Al) has 3 valence electrons and loses 3 electrons to achieve a stable configuration.
• Barium (Ba) has 2 valence electrons and loses 2 electrons to achieve a stable configuration.
• Oxygen (O) has 6 valence electrons and can gain 2 electrons to achieve an octet.
• Iodine (I) has 7 valence electrons and can gain 1 electron to achieve an octet.
• Carbon (C) has 4 valence electrons and can gain or lose electrons depending on the situation.
• Francium (Fr) has 1 valence electron and loses 1 electron to achieve a stable configuration.
• Lithium (Li) has 1 valence electron and loses 1 electron to achieve a stable configuration.

Step3: Answer question 21

Valence electrons used by an element:

• Fluorine: 7
• Phosphorus: 5
• Calcium: 2
• Nitrogen: 5
• Strontium: 2
• Argon: 8
• Potassium: 1
• Helium: 2
• Magnesium: 2
• Sulfur: 6
• Hydrogen: 1
• Aluminum: 3
• Barium: 2
• Oxygen: 6
• Iodine: 7
• Carbon: 4
• Francium: 1
• Lithium: 1

Step4: Answer question 22

Elements that want to lose electrons: Calcium (Ca), Strontium (Sr), Potassium (K), Magnesium (Mg), Aluminum (Al), Barium (Ba), Francium (Fr), Lithium (Li)

Step5: Answer question 23

Elements that want to gain electrons: Fluorine (F), Phosphorus (P), Nitrogen (N), Sulfur (S), Hydrogen (H), Oxygen (O), Iodine (I)

Step6: Answer question 24

Elements that want to gain electrons do so to achieve a stable electron configuration (usually an octet or duet for H and He). Elements that want to lose electrons do so to achieve a stable electron configuration (usually a noble - gas configuration).

Answer:

1. Fluorine: 7; Phosphorus: 5; Calcium: 2; Nitrogen: 5; Strontium: 2; Argon: 8; Potassium: 1; Helium: 2; Magnesium: 2; Sulfur: 6; Hydrogen: 1; Aluminum: 3; Barium: 2; Oxygen: 6; Iodine: 7; Carbon: 4; Francium: 1; Lithium: 1
2. Calcium, Strontium, Potassium, Magnesium, Aluminum, Barium, Francium, Lithium
3. Fluorine, Phosphorus, Nitrogen, Sulfur, Hydrogen, Oxygen, Iodine
4. To achieve a stable electron configuration.