chemistry study investigation 5

Group 1 elements

Alkali metals

Group 2 elements

Alkaline earth metals

Group 17 elements

Halogens

Group 18 elements

Noble gases

Periodic table organization

Organized in order of increasing atomic number

Valence electrons

The outermost electrons of an atom

Maximum number of valence electrons

$$8$$

Core electrons

Inner electrons that are not valence electrons

Main-group elements

Elements located in the s-block and p-block

Atomic radius trend

Increases down a group and to the left across a period

Effective nuclear charge ($Z_{eff}$)

The net positive attractive force felt by an electron from the nucleus

$Z_{eff}$ trend across a period

Increases from left to right across a period

Cation

A positively charged ion formed when an atom loses electrons

Anion

A negatively charged ion formed when an atom gains electrons

Reason cations are smaller than parent atoms

Loss of electrons reduces electron-electron repulsion and may eliminate the outermost energy level

Reason anions are larger than parent atoms

Gain of electrons increases electron-electron repulsion, expanding the electron cloud

First ionization energy trend

Increases moving up a group and to the right across a period

Electron affinity

The energy change that occurs when a neutral atom gains an electron

Reason noble gases have low electron affinities

They already possess a full valence electron shell

Cesium electron configuration

$$[Xe]6s^1$$

Sulfur electron configuration

$$[Ne]3s^2 3p^4$$

Copper electron configuration

$$[Ar]4s^1 3d^{10}$$

Bromine electron configuration

$$[Ar]4s^2 3d^{10} 4p^5$$

Chromium electron configuration

$$[Ar]4s^1 3d^5$$

Element with the largest atomic radius

Francium ($Fr$)