Students explore the concept that chemical reactions involve the breaking of bonds between atoms in the reactants, and the rearrangement and rebonding of these atoms to make the products. Students ...

The speed of a chemical reaction is affected by temperature, concentration, particle size and the presence of a catalyst. It can be calculated by measuring changes in reactants/products.

A change is called irreversible if it cannot be changed back again. Many chemical reactions are irreversible. In a chemical reaction, new materials are always formed. Sometimes these new materials ...

The lesson can also be used to lay a foundation for learning about changes in state and chemical changes which can be further developed in later grades. If water is cooled enough it can change to ice.

First, tadpoles grow back legs, then front ones. Skin grows over the gills they use to breathe underwater. Their tails shrink and eventually disappear.

BofA revised ratings on chemical stocks amid a diverse chemical end markets and changed risk/reward views after a 15% ...