Question

remplis le tableau.
ia (alcalins
exemple) iia (alcalino-
terreux) iiia iva va via viia (halogènes) viii a (gaz
inertes)
a) nombre
délectrons
de valence. 1 2 3 4 5 6 7 8
b) tendance à
perdre ou
à gagner des
électrons? perdre
1e⁻ perdre
2e⁻ perdre
3e⁻ perdre
ou
gagner
4e⁻ gagner
3e⁻ gagner
2e⁻ gagner
1e⁻ aucun
d) ions formés par
les éléments de la
3ᵉ période du
tableau périodique. na⁺

Explanation:

To fill in the table for the 3rd period elements (3ᵉ période) of the periodic table, we analyze each group (IA to VIII A) :

Part (c) : Ions formés par les éléments de la 3ᵉ période

We identify the 3rd period elements in each group and their ions:

• IIA (alcalino - terreux) : The 3rd period element is Magnesium (Mg). It loses 2 electrons (from part b: Perdre 2e⁻), so the ion is $\boldsymbol{Mg^{2+}}$.
• IIIA : The 3rd period element is Aluminum (Al). It loses 3 electrons (from part b: Perdre 3e⁻), so the ion is $\boldsymbol{Al^{3+}}$.
• IVA : The 3rd period element is Silicon (Si). It can lose or gain 4 electrons (from part b: Perdre ou gagner 4e⁻). Common ions: $\boldsymbol{Si^{4+}}$ (losing) or $\boldsymbol{Si^{4 -}}$ (gaining, less common; often forms covalent bonds, but for ionic context, $Si^{4+}$ is typical).
• VA : The 3rd period element is Phosphorus (P). It gains 3 electrons (from part b: gagner 3e⁻), so the ion is $\boldsymbol{P^{3 -}}$.
• VIA : The 3rd period element is Sulfur (S). It gains 2 electrons (from part b: gagner 2e⁻), so the ion is $\boldsymbol{S^{2 -}}$.
• VIIA (halogènes) : The 3rd period element is Chlorine (Cl). It gains 1 electron (from part b: gagner 1e⁻), so the ion is $\boldsymbol{Cl^{-}}$.
• VIII A (gaz inertes) : The 3rd period element is Argon (Ar). It has no tendency to gain/lose electrons (from part b: Aucun), so it remains neutral: $\boldsymbol{Ar}$ (no ion, or "Aucun ion" as it is a noble gas).

Filled Table (Part c) :

Groupe	IA (alcalins)	IIA (alcalino - terreux)	IIIA	IVA	VA	VIA	VIIA (halogènes)	VIII A (gaz inertes)

for Trends (Parts a - b, for context) :

• (a) Nombre d’électrons de valence : Matches the group number (IA = 1, IIA = 2, ..., VIII A = 8).
• (b) Tendance à perdre/gagner électrons :
• Groups IA - IIIA (metals) lose electrons (to reach noble gas configuration).
• Group IVA: Can lose (metalloids/metals) or gain (non - metals) 4 electrons.
• Groups VA - VIIA (non - metals) gain electrons (to reach 8 valence electrons).
• Group VIII A (noble gases): Already have 8 valence electrons → Aucun (no gain/loss).

If you need to fill other parts (a/b) or clarify, let me know! For part (c) as requested, the ions are as above.

Answer:

for Trends (Parts a - b, for context) :

• (a) Nombre d’électrons de valence : Matches the group number (IA = 1, IIA = 2, ..., VIII A = 8).
• (b) Tendance à perdre/gagner électrons :
• Groups IA - IIIA (metals) lose electrons (to reach noble gas configuration).
• Group IVA: Can lose (metalloids/metals) or gain (non - metals) 4 electrons.
• Groups VA - VIIA (non - metals) gain electrons (to reach 8 valence electrons).
• Group VIII A (noble gases): Already have 8 valence electrons → Aucun (no gain/loss).

If you need to fill other parts (a/b) or clarify, let me know! For part (c) as requested, the ions are as above.