Atoms, Elements, and the Periodic Table

C is the symbol for what element?

He is the symbol for what element?

Elements in the same group have __________ in common than elements in the same period.

___________________ are neutrally charged particles located in the nucleus of an atom.

________________ are the most reactive nonmetal elements on the periodic table.

Atomic number is based on the number of _________________ in an atom.

The number of _________________equals atomic mass minus atomic number.

Columns (up and down) on the periodic table are called ________________.

Na is the symbol for what element?

_________________ are the least reactive group of elements on the periodic table.

A _______________ is a positively charged particle located in the nucleus of an atom.

In an atom, protons are always equal to _________________.