Answer:
They break and reform bonds
Explanation:
Chemical reactions basically refer to the transformation of a substance (reactant) to another substance (products).
So we have;
Reactant --> Product
They can go in just one direction.
This option is wrong, because there are reversible reactions which can go in both directions. That is reactants reactants to form products and products react to form reactants.
They occur only in science labs.
This is wrong because chemical reactions occur in our day to day activities. An example is rusting.
They break and reform bonds.
This option is correct. There is breaking of bonds in the reactants and forming of new bonds in the products.
They create new elements
Atoms or elements are not created nor destroyed in chemical reactions so this option is wrong.
