2B.2 Periodic properties

Question 1

what are periodic properties (periodicity)

Answer 1

it is the regularly repeating patterns of atomic, physical, and chemical properties that can be predicted using the periodic table and explained using electronic configuration

Question 2

what are atomic radii

Answer 2

it is the measure of a size of an atom. it is the distance from the nucleus to the boundary of the electron cloud

Question 3

how do we find atomic radii?

Answer 3

now since the electron boundary isn’t very well defined what we would do is find the distance between 2 nuclei in 2 atoms boned together and divide them by 2

Question 4

what are the types of radii

Answer 4

1. covalent radii
2. van der Waals radii (for elements that dont bond with other elements ie argon and neon)
3. metallic radii

Question 5

across the period what happens to the radius

Answer 5

it decreases because the nuclear pull is stronger

Question 6

why does hydrogen have less ionization energy than helium

Answer 6

because helium would have 2 protons making have a stronger nuclear pull

Question 7

explain the anomaly of Be and boron

Answer 7

now it’s true that the ionization energy should increase across the period but there are some ionization energies that don’t follow the pattern, for example, Be and B that is because even though b has a higher nuclear charge it is in a 2p orbital which has more energy to 2s orbital so we need less ionization energy, upon that the outer most electron in b experiences more electron to electron repulsion from the two full inner shells

Question 8

explain the anomaly of Be and boron

Answer 8

now it’s true that the ionization energy should increase across the period but there are some ionization energies that don’t follow the pattern, for example, N and O, so even though oxygen has a higher nuclear charge it has a less first IE and that is because its outermost electron is in a full subshell making it have a higher electron to electron replusion