Answer:
1. Trends that exist in the periodic table include:
- Atomic size: atomic radius generally decreases from left to right across a period and increases from top to bottom down a group.
- Ionization energy: the energy required to remove an electron from an atom generally increases from left to right across a period and decreases from top to bottom down a group.
- Electronegativity: the ability of an atom to attract electrons in a chemical bond generally increases from left to right across a period and decreases from top to bottom down a group.
- Metallic character: metals are generally located on the left side of the periodic table and become less metallic going to the right and up the table.
- Nonmetallic character: nonmetals are generally located on the right side of the periodic table and become more nonmetallic going to the right and up the table.
- Reactivity: the reactivity of elements varies depending on the type of reaction and the group or period an element is in.
2. The periodic table provides a wealth of information about each element, including:
- Atomic number: the number of protons and electrons in an atom's nucleus
- Element symbol: an abbreviation used to represent each element
- Element name: the full name of the element
- Atomic mass: the mass of an atom, expressed in atomic mass units (amu)
- Group: the vertical columns in the periodic table, which share similar chemical and physical properties
- Period: the horizontal rows in the periodic table, which show trends in atomic properties
- Electron configuration: the arrangement of electrons in an atom's orbitals
- Oxidation state: the number of electrons an atom gains, loses, or shares when forming a chemical compound
- Physical properties: such as melting point, boiling point, density, color, and state (solid, liquid, gas)
- Chemical properties: such as reactivity, bond formation, and acid-base behavior.