Na 2
ОО
20 points
What contains the protons and neutrons of an atom and also has most of the mass of an atom?
atomic number
electron cloud
nucleus
the period
3
20 points
An electron
has a positive charge, is inside the nucleus and has almost no mass.
has a neutral charge, is outside the nucleus and has a mass of lau.

The diagin dilutepage 6 of 12a6a5(a)fluorine, chlorine, bromine and iodine are placed in the same group of theperiodic table.state the common name used to describe elements in this group.(i)state the group in which the elements are placed and explain whythey are placed in that group.(ii)which of the above named elements is a solid at roomtemperature and pressure?