Question

how are the elements in todays modern periodic table arranged?

in order of decreasing atomic mass

in order of increasing atomic mass

in order of decreasing atomic number

in order of increasing atomic number

Explanation:

The modern periodic table arranges elements by atomic number. Atomic number is the number of protons in an atom's nucleus. As we move from left to right across the table, the atomic number increases. This is a fundamental principle in chemistry.

Answer:

in order of increasing atomic number