Across
- 3. cycle - A method by which carbon is constantly moved throughout the biosphere.
- 4. reaction - A process where a set of substances undergo a chemical change to form a different substance.
- 6. A table of the chemical elements arranged by atomic number.
- 7. - The ability of a material to be stretched into a long wire.
- 9. The central core of an atom containing the protons and neutrons.
- 11. A particle within the nucleus of an atom that holds a positive charge.
- 12. - A molecule is formed when two or more atoms are joined together by a chemical bond.
- 13. - Density is the mass per unit volume of a substance.
- 15. - A substance is said to be malleable if it can be pounded into a thin sheet.
- 16. A family of elements that makes up column 18 of the periodic table. They are very stable due to their full outer electron shells.
- 22. The name for the process when oxygen combines with another element to form a compound.
- 23. Salts are chemical compounds that are formed by the reaction of an acid and a base.
- 25. - A substance that speeds up the rate of a chemical reaction. The catalyst is not consumed in the reaction.
- 28. - A conductor is a material that allows the flow of energy such as heat or electricity.
- 29. A homogeneous mixture where one substance called the solute is fully dissolved into another substance called the solvent. For example, a solution is formed when salt dissolves into water to make the solution salt water.
- 31. - An alloy is a metallic mixture of two or more elements. Examples of alloys include brass, bronze, and steel.
- 32. solution - Any solution where water is the solvent.
- 33. A particle in the nucleus of an atom that has no electric charge.
- 34. - A combination of two or more substances that are not chemically combined.
- 35. burner - A piece of chemistry lab equipment that produces a flame used for lab experiments.
- 38. - A particle of an atom that orbits the atom's nucleus and carries a negative charge.
Down
- 1. An electron in an atom that can participate in a chemical bond.
- 2. earth metals - The alkaline earth metals are the elements in the second column of the periodic table.
- 3. bond - Covalent bonding occurs between atoms that share a pair of electrons in order to gain full outer shells.
- 5. bond - Ionic bonding is when an electron is traded between atoms in order to have full outer shells.
- 8. - An attraction between atoms that forms chemical substances.
- 10. - A process used to drive a chemical reaction by using an electrical current. It is often used to separate elements.
- 11. The pH measures the activity of the hydrogen ion in substances. If a substance has a pH less than 7 it is said to be acidic. If its pH is greater than 7 then it said to be basic or alkaline.
- 14. - A base is a substance with a pH higher than seven. Bases are defined as donating a pair of valence electrons.
- 17. - Allotropes are different forms in which the same element can exist. For example, the element carbon can take the form of the allotrope graphite or the allotrope diamond.
- 18. - A substance that is a good conductor of heat and electricity. They are generally malleable, ductile, and shiny.
- 19. - The process of separating mixtures by boiling a liquid and then recovering the cooled gas.
- 20. metals - The alkali metals are the elements in the first column of the periodic table with the exception of hydrogen.
- 21. The process that occurs when two or more chemical substances are combined to form another chemical substance.
- 24. - Isotopes are atoms from the same element that have different numbers of neutrons.
- 26. - The atom is a basic unit of matter and the smallest unit of an element. It consists of a nucleus which is surrounded by a cloud of electrons.
- 27. - A chemical compound is a pure substance made up of two or more elements.
- 30. - The study of chemical processes as they relate to living organisms.
- 32. - An acid is a compound with a pH of less than 7 that forms hydrogen ions when dissolved in water. Acids react when coming into contact with bases and some metals to form salts.
- 36. - A pure chemical substance that is made up of one type of atom. Each atom in an element is defined by an atomic number which is the number of protons in the nucleus.
- 37. - An atom or molecule which has a negative or positive charge because the number of electrons does not equal the number of protons.