Online Chemistry Notes for Students
Polar Molecules Definition A polar molecule is a chemical substance in which the distribution of electrons between the atoms involved is uneven, resulting in a dipole moment. The term polarity is used to describe the difference in electrical poles of a molecule which then determines how polar the molecule is. The determination of whether or … Read more
Physical Change Definition A physical change is a process that changes the physical form of a substance but not its chemical composition. During a physical change, the molecules of a substance are rearranged, but the chemical composition of the substance remains unchanged. A physical change usually involves a change in physical properties like the change … Read more
Natural Polymers Definition Natural polymers are natural substances composed of large macromolecules formed by the binding of small molecules called monomers. Natural polymers occur in the form of chemical compounds in biological systems and can be broadly categorized into three groups; polysaccharides, polyamides, and polynucleotides. Polymers are not restricted to monomers of the same chemical … Read more
Molecules Definition A molecule is a group of two or more atoms of the same or different atoms that represent the smallest identifiable unit of a substance that has the composition and chemical properties of the substance. Molecules are individual units of a pure substance or a compound that interact with each other to provide … Read more
Molar Mass Definition Molar mass is the mass of one mole of a substance obtained by the mass of a compound divided by the amount of the substance present in the compound. Molar mass is considered an average mass of the molecules as the molecular mass might be varied due to the presence of isotopes. … Read more
Hard Water Definition Hard water is the water with a high mineral content which is formed by the percolation of water through deposits of mineral rocks like limestone. Hard water contains chemical ions like bicarbonates, carbonates, and sulfates of calcium and magnesium. Some hard water might also contain iron oxides or iron carbonates resulting in … Read more
Elements Definition Elements are pure substances that consist of a single type of atoms and cannot be broken down into smaller units by chemical means. Elements are basic chemical species that combine with other elements to form complex species like compounds and molecules. Elements are defined by the number of protons in the nucleus, which … Read more
Solute Definition A solute is a substance that is added to a solvent to form a solution. The solute can exist in all three forms of matter as solid, liquid, or gas. In a homogenous mixture, the solute completely dissolves in another substance, and the solute is uniformly distributed throughout the solution. In a heterogeneous … Read more
Atomic Mass Definition Atomic mass is the mass of an atom or an isotope which includes the total mass of the nucleus and the electrons present in the periphery. Most of the contribution is made by the nucleus as it contains the heavier subatomic particles, while lesser contributions are made by the electrons and nuclear … Read more
Atom Definition An atom is the smallest unit of matter composed of a nucleus and one or more electrons present around the nucleus. The atom is characteristic of the chemical element and is often considered the basic building block of chemistry. The atom consists of a large empty space while the rest is occupied by … Read more