Question

Consider this row in the periodic table of elements. As we move from left to right, across the row, the elements ... A) change from nonmetals to metals. B) change from metals to nonmetals. C) start as gases but end as solids. D) show a decrease in atomic mass number.

Answer 1

The answer is: B) change from metals to nonmetals.

For example, alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons (one electron, earth alkaline metals (right next to alkaline metals) have higher ionization energy than alkaline metals, because they have two valence electrons.

Nonmetals are far right in the main group and they have highest ionization energy, because they have many valence electrons.

Atomic number is the number of protons, which is characteristic of a chemical element. Atomic number increases from left to right in Periodic table.

Answer 2

B) change from metals to nonmetals.