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.

B) change from metals to nonmetals.

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.

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !