Question

how are the atomic mass numbers of the elements arranged on the periodic table of elements?
o a. atomic mass decreases diagonally.
o b. atomic mass increases from bottom to top.
o c. atomic mass decreases from left to right.
o d. atomic mass increases from left to right.

Explanation:

The periodic table arranges elements in order of increasing atomic number. Generally, as atomic number increases, atomic mass also increases. In a period (row), atomic mass increases from left to right.

Answer:

D. Atomic mass increases from left to right.