Question

Which option correctly describes the pattern of valence electrons on the periodic table?(1 point)

1.The number of valence electrons increases from top to bottom.

2.The number of valence electrons increases from bottom to top.

3.The number of valence electrons increases from left to right.

4.The number of valence electrons increases from right to left.

Answer 1

The pattern of valence electrons in the periodic table is such that the number of valence electrons increases from left to right across a period. This pattern can be seen in the arrangement of group numbers, particularly in the s and p blocks of the periodic table. Option 3

Step-by-step explanation:

The correct option describing the pattern of valence electrons in the periodic table is that the number of valence electrons increases from left to right across a period. This increase is due to the addition of a proton to the nucleus and an electron to the valence shell with each successive element in the period. In each group, the number of electrons in the valence shell remains constant, but the principal quantum number increases down the group.

For instance, in the s block, Group 1 elements have one valence electron, and Group 2 elements have two. In the p block, the number of valence electrons corresponds to the group number minus ten: Group 13 elements have three valence electrons, while Group 18 elements (noble gases) have eight, completing their valence shell for stability.

So, the correct answer is:

The number of valence electrons increases from left to right. option 3

Answer 2

1. valence electrons and electronegativity

2. Both reactivity and electronegativity decrease down a group.

3. Electronegativity decreases down a group, and reactivity increases down a group.

4. The number of valence electrons increases from left to right.

5. Cs

Explanation: I did it