Across
- 4. chemical rule of thumb that reflects observation that atoms of main-group elements tend to combine in such a way that each atom has eight electrons in its valence shell
- 7. having legal force
- 10. which a single compound breaks down into two or more elements or new compounds
- 12. name given to a horizontal row of the periodic table
- 16. The central part of an atom that contains the protons and neutron
- 17. results in the formation of new chemical substances
- 18. the law that the properties of the elements are periodic functions of their atomic numbers
- 20. exothermic reaction in which something reacts with oxygen
- 22. a substance made by mixing other substances together.
- 23. total number of protons and neutrons
- 24. smallest component of an element
- 26. lasting attraction between atoms that enables the formation of chemical compounds
- 28. a positive charged ion
- 29. type of chemical reaction where an element reacts with a compound and takes the place of another element in that compound.
- 34. substances that are made of only one type of atom or only one type of molecule
- 38. stored in the bonds of chemical compounds
- 40. not consistent or having a fixed pattern
- 41. tryout or experiment to test quality
- 42. number or symbol multiplied with a variable or an unknown quantity in an algebraic term
- 44. various particles of matter that are smaller than a hydrogen atom
- 46. smallest of the particles that make up an atom, and they carry a negative charge
- 47. substance that is formed as the result of a chemical reaction
- 48. an element (e.g., germanium or silicon) whose properties are intermediate between those of metals and solid nonmetals.
- 49. which two or more simple substances combine to form a more complex product
- 50. electrically charged atom or group of atoms formed by the loss or gain of one or more electrons
- 52. 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.
- 56. also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms.
- 57. A mixture which has uniform composition and properties throughout
- 58. two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons
- 59. Elements that form cations when compounds of it are in solution and oxides of the elements form hydroxides rather than acids in water
- 60. characteristic of a substance that is observed during a reaction in which the chemical composition
Down
- 1. A mixture is a combination of two or more pure substances in which the original substances retain their chemical properties
- 2. a variable (often denoted by x ) whose variation does not depend on that of another.
- 3. is a measure of mass per volume
- 5. property or characteristic of a substance that is observed during a reaction in which the chemical composition or identity of the substance is changed
- 6. type of chemical reaction where two compounds react, and the positive ions (cation) and the negative ions (anion) of the two reactants switch places
- 8. mass of an isotope of an element measured in units
- 9. chemical reaction in the form of symbols and formulae
- 11. is a column of elements in the periodic table of the chemical elements
- 13. a thing that is composed of two or more separate elements
- 14. a substance that takes part in and undergoes change during a reaction.
- 15. process describes a process or reaction in which the system absorbs energy from its surroundings
- 19. needs to be balanced so that it follows the law of conservation of mass
- 21. unchanging standard of comparison in scientific experimentation
- 25. chemical element (as boron, carbon, or nitrogen) that lacks the characteristics of a metal and that is able to form anions, acidic oxides, acids, and stable compounds with hydrogen.
- 27. the variable being tested in a scientific experiment
- 30. chemical reaction that releases energy by light or heat
- 31. color, smell, freezing point, boiling point, melting point
- 32. is a subatomic particle found in the nucleus of atoms that differs from the other subatomic particles
- 33. set of chemical symbols showing the elements present in a compound and their relative proportions
- 35. process that involves rearrangement of the molecular
- 36. is a charged chemical species (ion) composed of two or more atoms covalently bonded
- 37. form when one atom gives up one or more electrons to another atom
- 39. changes affecting the form of a chemical substance
- 43. explanation made on the basis of limited evidence as a starting point for further investigation.
- 45. substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change.
- 51. regions of space around the nucleus of an atom where an electron is likely to be found
- 52. negative charged ion
- 53. Particle found in a nucleus with a positive charge
- 54. substances that cannot be chemically interconverted or broken down into simpler substances and are primary constituents of matter
- 55. assumed to have a fixed value in a specified mathematical context