They all have the same number of energy levels. That's about it.
All member of the same period share the same number of energy levels. The energy levels range from one up to seven.
Atoms of nonmetals tend to be smaller than atoms of metals in the same period.
same no of protons
They are the same
Three electrons in their valency orbit.
bromine, i think
They have similar properties as well as levels of reactivity
number of valence electrons
All atoms of any single element have the same number of protons and electrons.
they have the same energy levels
The period number is the same as the highest energy level containing electrons for the atoms in that period.
There are 17 elements larger than calcium (Ca) on the periodic table in calcium's period.