When moving across a period from left to right in the periodic table (excluding transition elements) which trend occurs?(1 point)ResponsesValence electrons decrease by one.Valence electrons decrease by one.Valence electrons increase by one.Valence electrons increase by one.The energy levels decrease by one.The energy levels decrease by one.The energy levels increase by one.The energy levels increase by one.
The trend that occurs when moving across a period from left to right in the periodic table (excluding transition elements) is that the number of valence electrons increases by one.
When moving across a period from left to right in the periodic table (excluding transition elements), the trend that occurs is that the number of valence electrons increases by one.
When moving across a period from left to right in the periodic table (excluding transition elements), the trend is that the number of valence electrons increases by one.
To determine this trend, you can look at the electronic configuration of the elements in the periodic table. Each row in the periodic table corresponds to a period, and as you move from left to right in a period, the number of valence electrons increases by one.
Valence electrons are the outermost electrons in an atom that are involved in chemical bonding. They determine the chemical properties of an element. For example, elements in Group 1 (alkali metals) have one valence electron, while elements in Group 17 (halogens) have seven valence electrons.
To understand this trend, you can also use the concept of the periodic table's periodicity. As you move across a period, the atomic number of the elements increases, indicating that the number of protons in the nucleus is increasing. Since the number of protons determines the number of electrons in a neutral atom, the number of valence electrons also increases as you move across a period from left to right.
In summary, the correct response is: Valence electrons increase by one.