Question

which group or family of elements have a stable electron configuration? * 1 point
○ alkali metals
○ carbon family
○ halogens
○ noble gases

the chemical properties of an element depend on * 1 point
○ the number of valence electrons.
○ the size of the atom.
○ the number of total electrons.
○ the mass of the atom.

Explanation:

First Question:

To determine which group has a stable electron configuration, we analyze each option:

• Alkali metals (Group 1) have 1 valence electron, making them reactive (they lose this electron to achieve stability).
• Carbon family (Group 14) has 4 valence electrons, and they are not inherently stable (they form bonds to achieve stability).
• Halogens (Group 17) have 7 valence electrons, making them reactive (they gain 1 electron to achieve stability).
• Noble gases (Group 18) have a full valence shell (8 electrons, except He with 2), giving them a stable electron configuration.

To determine what chemical properties depend on, we analyze each option:

• Valence electrons: These are the outermost electrons involved in bonding. The number of valence electrons determines how an element reacts (e.g., metals lose electrons, non - metals gain electrons).
• Size of the atom: While atomic size affects physical properties (like atomic radius) and some chemical aspects indirectly, it is not the primary determinant of chemical properties.
• Number of total electrons: The total number of electrons includes core electrons which do not participate in chemical reactions, so it does not determine chemical properties.
• Mass of the atom: Atomic mass is related to the number of protons and neutrons, which do not directly determine how an element reacts chemically.

Answer:

D. noble gases

Second Question: