Across
- 2. energy- energy that is needed to get a reaction started
- 5. electron- electron found in the outermost shell of an atom; helps to determine bonding
- 7. charged particle that orbits the nucleus in the electron cloud
- 8. number-the number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table (also equals the number of electrons in an element)
- 11. reaction- a reaction that absorbs energy (absorbs heat)
- 13. in a molecule, uneven distribution of electrons (results in (+) and (-) poles) ex. water
- 14. basic unit of matter
- 15. elements or compounds that enter into a chemical reaction
- 17. force of attraction between different kinds of molecules
- 18. symbol- one- or two-letter abbreviation for a chemical element name
- 20. formed as a result of a chemical reaction
- 22. biological catalysts
- 23. mass-equal to the total number of protons and neutrons in the nucleus of an atom (based on isotopes)
- 24. pure substance that consists entirely of one type of atom
- 26. reactant of an enzyme-catalyzed reaction
- 27. bonding-- weak attraction between a hydrogen atom and another atom
Down
- 1. (chemistry definition) the center of an atom, which contains the protons and neutrons
- 3. reaction- process that changes, or transforms, one set of chemicals into another set of chemicals
- 4. found in the nucleus that has no charge
- 6. bond- type of bond between atoms in which the electrons are shared
- 9. a combination of 2 or more elements connected by bonds
- 10. positively charged particle found in the nucleus of an atom
- 12. action-- tendency of water to rise in a thin tube
- 16. attraction between molecules of the same substance
- 19. substance that speeds up the rate of a chemical reaction
- 21. capacity (specific heat)-- the amount of heat needed to raise the temperature of 1 gram of a substance 1 degree Celsius (°C)
- 25. reaction- a reaction that releases energy (gives off heat)