Classify each statement about effective nuclear charge, Zeff, as true or false.
1. A 1s electron in a B atom has a smaller Zeff than a 1s electron in a Be atom.
2. Effective nuclear charge does not depend on the number of electrons present in an atom.
3. Across a period, as Zeff increases, atomic size increases.
4. Effective nuclear charge increases from left to right across a period on the periodic table.
5. In a Be atom, 1s electron has a greater Zeff than a 2s electron.
6. Electrons in an s orbital are more effective than those in other orbitals at shielding other elctrons from nuclear charge.