Basic chemistry concepts: atoms, molecules, chemical bonds (ionic, covalent), pH.

Atoms

Basic units of matter consisting of a nucleus with protons and neutrons, surrounded by electrons in energy levels.

Molecules

Formed by the chemical bonding of two or more atoms, can be of the same or different elements.

Ionic Bonds

Formed by electron transfer between atoms, resulting in oppositely charged ions attracting each other.

Covalent Bonds

Formed by electron sharing between atoms to achieve stability, can be polar or nonpolar.

Hydrogen Bonds

Weak attractions between a hydrogen atom with a partial positive charge and an electronegative atom with a partial negative charge.

pH

Measure of acidity or basicity in a solution, defined by the concentration of hydrogen ions (H+), affecting biological processes.