Second Semester Final Review

2. A region in an atom where there is a high probability of finding electrons.
4. Elements are arranged by increasing atomic number and by changes in properties
5. Transfer of thermal energy by collisions of particles (CONTACT)
7. The average kinetic energy of the particles of a substance
8. Negatively charged particle that moves around the nucleus of the atom
10. A chemical equation that has the same number of atoms of each element on both sides of the equation.
14. Transfer of thermal energy by electromagnetic waves
15. The minimum amount of energy needed to start a reaction
17. The transfer of energy from a higher temperature to a lower temperature
18. Atoms of the same element that have different numbers of neutrons
21. Transfer of thermal energy in a fluid from one place to another
22. Energy The sum of the kinetic and potential energy of the particles in an object
24. A chemical reaction in which energy is released.

1. Substance that speeds up a chemical reaction without being permanently changed itself
3. The energy required to raise the temperature of 1 gram of a substance by 1 degree
6. The sum of the number of protons and neutrons in the nucleus of an atom
9. An electron that is found in the outermost shell of an atom and that determines the atom’s chemical properties.
11. The number of protons in an atom’s nucleus
12. A chemical reaction in which energy is absorbed.
13. Atomic particle with no charge (neutral) that is part of the atom’s nucleus
16. Vertical columns in the periodic table
18. A substance that slows down a chemical reaction
19. Element or compound that cannot be broken down into simpler components and maintain the properties of the original substance
20. Energy Energy a moving object has because of its motion
23. Atoms of the same element that have a different number of electrons