When moving across a period from left to right in the periodic table (excluding transition elements) which trend occurs? (1 point)

Question

• Valence electrons increase by one.
• Valence electrons decrease by one.
• The energy levels decrease by one.
• The energy levels increase by one.

Answer 1

When moving across a period from left to right in the periodic table (excluding transition elements), the trend that occurs is:

Valence electrons increase by one.

This is because each successive element in the same period has an additional proton and an additional electron, leading to an increase in the number of valence electrons.