Chemistry: Science Terms Explained
Plain-language definitions of every chemistry term your child meets in school, each with kid-friendly explanations, worked examples, and common mistakes to watch for.
Law of conservation of mass
The law of conservation of mass is the science rule that says in a closed system, mass cannot be created or destroyed during a physical or chemical change; the total mass of all substances before the change is equal to the total mass after the change.
Metallic bond
A metallic bond is the attraction between positively charged metal ions and a "sea" of freely moving valence electrons that holds metal atoms together in a solid or liquid metal.
Molarity
Molarity is the concentration of a solution, defined as the number of moles of dissolved substance (solute) in 1 liter of solution.
Neutron
A neutron is a tiny particle found in the nucleus (center) of an atom that has mass but no electric charge, and it helps determine an atom's mass and which isotope of an element it is.
Noble gases
Noble gases are the group of elements in the far right column of the periodic table that are very stable and almost never react with other elements because their outer electron shells are full.
Oxidation
Oxidation is a type of chemical reaction where a substance loses electrons, often while reacting with oxygen, which usually increases the substance’s oxidation number and can release energy.
Periodic table
The periodic table is a chart that organizes all known chemical elements by their atomic number and by patterns in their properties, so scientists and students can quickly see how elements are related and predict how they might behave in chemical reactions.
PH scale
The pH scale is a numerical scale from 0 to 14 that measures how acidic or basic (alkaline) a water-based solution is, based on the concentration of hydrogen ions in the solution.
Precipitate
A precipitate is a solid that forms and separates out of a liquid mixture during a chemical reaction, often appearing as tiny particles that make the liquid look cloudy or as a solid that settles to the bottom.
Proton
A proton is a tiny positively charged particle found in the nucleus (center) of an atom, and the number of protons in the nucleus determines which element the atom is.
Reactant
A reactant is a starting substance in a chemical reaction, the material that is used up or changed to form new substances called products.
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