The size of an atom is determined by the size of its electron cloud.
The size of the electron cloud depends
The graphic shows the sizes of the elements in s- and p-block of the periodic table in picometres.
There are a variety of difficulties associated with measuring the sizes of atoms. It is possible to measure the distance between atoms in the elemental form of metals, but the radii of non-metals are often measured when they are combined with another atom in a covalent bond. Therefore the sizes reported may be different in tables from other sources.
What are the trends?
The size of the electron cloud for atoms of elements Strategy for answering questions:
Identify whether the atoms in the questions are in the same row or in the same group.
If there are atoms from more than one group/row,
The size of the electron cloud depends
on the number of the highest electronic shell occupied
on the nuclear charge
on the electron distribution
on the nuclear charge
on the electron distribution
The graphic shows the sizes of the elements in s- and p-block of the periodic table in picometres.
There are a variety of difficulties associated with measuring the sizes of atoms. It is possible to measure the distance between atoms in the elemental form of metals, but the radii of non-metals are often measured when they are combined with another atom in a covalent bond. Therefore the sizes reported may be different in tables from other sources.
What are the trends?
The size of the electron cloud for atoms of elements
at the bottom of a group in the periodic table are larger.
at the left in period of the periodic table are larger.
at the left in period of the periodic table are larger.
Identify whether the atoms in the questions are in the same row or in the same group.
If there are atoms from more than one group/row,
cluster the atoms for comparing them so that those from the same group are together and those from the same row are together.