Unit 4 review

4. A solid that forms and separates from a liquid solution as a sign of a chemical reaction.
6. A characteristic smell produced as a result of a chemical reaction occurring.
8. A chemical reaction that absorbs heat from its surroundings.
9. Electrons in the outermost shell of an atom that are involved in forming chemical bonds.
12. A chemical reaction that releases heat to its surroundings.
13. A simplified version of a structural formula that shows the atoms and their bonds but omits some details, often using shorthand to represent certain parts of the molecule.
15. A chemical bond in which two atoms share three pairs of electrons.
16. The speed at which a chemical reaction occurs typically increases when the temperature is raised.
17. The principle stating that mass is neither created nor destroyed in a chemical reaction, which is why chemical equations must be balanced.
18. A substance that speeds up a chemical reaction without being consumed in the process.

1. A symbolic representation of a chemical reaction, showing reactants, products, and their proportions.
2. A chemical bond in which two atoms share one pair of electrons.
3. The principle that energy cannot be created or destroyed, only transformed, in a chemical reaction.
5. A representation of a compound showing the elements and the number of atoms of each element in the compound.
6. A chemical compound primarily made of carbon atoms bonded with hydrogen, oxygen, and other elements, typically forming the basis of life.
7. The amount of a substance in a given volume, which can influence the rate of a chemical reaction.
10. A chemical bond in which two atoms share two pairs of electrons.
11. A representation of a molecule that shows all atoms and the bonds between them, illustrating the exact arrangement of atoms.
14. For example, a larger ________ of a solid, such as powdered sugar, reacts faster than a large lump of the same material because more of it is exposed to the other reactant.