Question

question 15 of 25
what determines an elements properties?
a. the core electrons
b. the valence electrons
c. the isotopes it forms
d. its atomic mass

Explanation:

To determine what determines an element's properties, we analyze each option:

• Option A: Core electrons are in the inner shells and do not significantly influence an element's chemical properties as they are relatively stable and not involved in bonding or typical chemical reactions.
• Option B: Valence electrons are the electrons in the outermost shell of an atom. These electrons are involved in chemical bonding, reactions, and interactions with other atoms, which directly determine an element's chemical properties (like reactivity, ability to form compounds, etc.).
• Option C: Isotopes are variants of an element with different atomic masses (due to different numbers of neutrons) but the same number of protons and electrons. Isotopes of an element have similar chemical properties because they have the same number of valence electrons, so isotopes do not determine an element's properties.
• Option D: Atomic mass is the sum of protons and neutrons in an atom. It affects physical properties like density in some cases but does not determine the chemical properties which are the main defining properties of an element in terms of its behavior in reactions.

Answer:

B. The valence electrons