Vocab 1
The smallest building block of all matter.
atom
The starting "ingredients" in a chemical reaction (found on the left side of an equation).
Reactant
The small number below and to the right of an atom's symbol that tells you how many of that specific atom are in a molecule.
Subscript
A reaction that absorbs energy, usually making the surroundings feel colder.
Endothermic
A tiny, negatively charged particle that zips around the outside of the nucleus.
Electron
Two or more atoms held together by chemical bonds.
Molecule
The new substance formed by a chemical reaction (found on the right side of an equation).
Product
A change that results in the formation of a new chemical substance.
Chemical change
The rule that matter is never created or destroyed; the mass of the reactants must equal the mass of the products.
A pure substance made of only one kind of atom (like Oxygen or Iron).
Element
A specific type of matter that is the same all the way through (like pure water or gold).
Substance
A written representation of a reaction using symbols and numbers.
chemical equation
A change in appearance (like melting or tearing) that does not create a new substance.
Physical change
The tiny, dense center of an atom that holds the protons and neutrons.
Nucleus
The organized chart that shows all the known elements in the universe.
Periodic table
A characteristic of a substance (like color, smell, or boiling point) that helps identify it.
Property
What molecule comes from 2H2 and O2
H2O
A solid that forms inside a liquid during a chemical reaction (it often looks like "clouds" in a test tube).
Precipitate
A subatomic particle with a positive charge found inside the nucleus.
Proton
A combination of two or more substances that are together in the same place but are not chemically bonded (like a salad or sand and water).
Mixture
A process where atoms rearrange to create one or more new substances.
Chemical reaction
The big number in front of a chemical formula that tells you how many molecules there are.
Coefficient
A reaction that releases energy, usually making the surroundings feel hotter.
Exothermic
A subatomic particle with no charge (neutral) found inside the nucleus.
Neutron
A special type of mixture where one substance dissolves perfectly into another (like salt water).
Solution