Chapter 2 lesson 1 the Nature of Matter Page 34 -53

Atoms

1.  The Study of chemistry begins with the basic unit of matter, the atoms.

Key Note: The Subatomic particles that make up atoms are Proton, Neutrons and Electrons.

2.       Strong forces bind protons and neutrons together to form the nucleus which is at the center of the atom.

3.       The electron is a negatively charged particle (-) with 1/1840 the mass of a proton.

4.       Atoms of the same element that differ in the number of neutrons they contain are known as isotopes.

Key Note: Because they have the same number of electrons all isotopes of an element have the same chemical properties.

Chemical Compounds

1.        A chemical compounds is a substance formed by the chemical combination of two or more elements in definite proportions.

2.       The main types of chemical bonds are ionic bonds & covalent bonds.

3.       An ionic bond formed when one or more electrons are transferred from one atom to another.

4.       A covalent bond forms when electrons are shared between atoms.

5.       The molecule is the smallest unit of most compounds.

6.       Chemists call such intermolecular forces of attraction van der waals forces, after the scientist who discovered them.

Chapter 2 lesson 2

7.       A water molecule is polar because there is an uneven distribution of electron between the oxygen and hydrogen atoms.

8.       Cohesion is an attraction between molecules of the same substance.

9.       A mixture is a material composed of two or more elements or compounds that are physically mixed together but not chemically combined.

10.   All the components of a solution are evenly distributed throughout the solution.

11.   In a salt water solution, table salt is the solute – the substance that is dissolved.

12.   Water is the solvent – the substance in which the solute dissolves.

13.   Such mixtures of water and nondissolved material are known as suspensions.

14.   Chemists devised a measurement system called the pH scale to indicate the concentration of H+ ions in solution.

15.  An acid is any compound that forms H+ ions in solution.

16.   Acidic solutions contain higher concentrations of H+ ions than pure water and have pH values below 7.

17.   A base is a compound that produces hydroxide ions (OH¯ ions) in solution.

18.   Basic, or alkaline, solutions contain lower concentrations of H+ ions than pure water and have pH values above 7.

19.   Buffers are weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in Ph.

Chapter 2 Lesson 3

20.   The smaller units, or monomers, join together to form polymers.

21.   Four groups of organic compounds found in living things are carbohydrates, lipids, nucleic acids, and proteins.

22.   Carbohydrates are compounds made up of carbon, hydrogen, and oxygen atoms, usually in a ratio of 1:2:1.

23.   Living things use carbohydrates as their main source of energy. Plants and some animals also use carbohydrates for structural purposes.

24.   Single sugar molecules are also called monosaccharides are known as polysaccharides.

25.   Lipids are made mostly from carbon and hydrogen atoms.

26.   Lipids can be used to store energy. Some lipids are important parts of biological membranes and waterproof covering.

27.   Nucleic acids are macromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus.

28.   Nucleotides consist of three parts: a 5-carbon sugar, a phosphate group, and a nitrogenous base, as shown in figure 2-15.

29.   Nucleic acids store and transmit hereditary, or genetic, information.

30.   There are two kinds of nucleic acids: Ribonucleic acid (RNA) & Deoxyribonucleic acid (DNA).

31.   Proteins are macromolecules that contain nitrogen as well as carbon, hydrogen, and oxygen.

32.   Proteins are polymers of molecules called amino acids.

33.   Some proteins control the rate of reactions and regulate cell processes. Some are used to form bones and muscles. Other transport substances into or out of cells or help to fight disease.

Chapter 2 lesson 4

34.   A Chemical reaction is a process that changes one set of chemicals into another set of chemicals.

35.   The elements or compounds that enter into a chemical reaction are known as reactants.

36.   The elements or compounds produced by a chemical reaction are known as products.

37.   Chemical reactions always involve the breaking of bonds in reactants and the formation of new bonds in products.

38.   Chemical reactions that release energy often occur spontaneously. Chemical reactions that absorb energy will not occur without a source of energy.

39.   Chemists call the energy that is needed to get a reaction started the activation energy.

40.   A catalyst is a substance that speeds up the rate of a chemical reaction.

41.   Enzymes are proteins that act as biological catalysts.

42.   Enzymes speed up chemical reactions that take place in cells.

43.   The reactants of enzyme-catalyzed reactions are known as substrates.

To refresh your memory please go to your biology book for the figures & pictures.