The Basics Of Life

1. The Basics Of Life Chemistry

2. Matter, Energy, and Life • All life forms are composed of matter and use energy to carry out processes. • Matter is anything that has mass. • Energy is the ability to do work.

4. Chemistry • Chemistry is the science concerned with the study of the composition, structure, and properties of matter and the changes it undergoes. • Both living matter and non-living matter have the same basic building blocks.

6. Two General Types of Energy • Kinetic energy is the energy of motion. • Potential energy is stored energy. It is energy that is not yet doing work. • Potential energy is stored in matter and chemicals. It can be converted to kinetic energy to perform some sort of work.

11. 1st Law of Thermodynamics • The 1st law of thermodynamics is also known as the law of conservation of energy. • Energy is never created or destroyed. • Energy can be converted from one form to another, but the total energy remains constant.

12. Five Forms of Energy • 1. Mechanical. • 2. Nuclear. • 3. Electrical. • 4. Radiant. • 5. Chemical. • All of these forms can be either kinetic or potential.

13. Mechanical Energy • Mechanical energy is associated with machines or things in motion. • Mechanical energy becomes kinetic when objects come into motion.

15. Nuclear Energy • Nuclear energy is energy from reactions at the atomic nucleus of matter.

18. Electrical Energy • Electrical energy (electricity) is the flow of charged particles. • All metabolic reactions involve electrical energy.

22. Radiant Energy • Radiant energy takes many forms including, but not limited to, the following: • Heat • Visible light • X-radiation • Microwaves

25. Chemical Energy • Chemical energy is a type of potential energy stored in matter. • When chemicals are changed from one form to another, it is released as kinetic energy. • Cellular respiration is the method living things utilize to release chemical energy.

28. Atom • Atoms are the smallest units of matter that can exist alone. • Elements are fundamental chemical substances made up of collections of only one kind of atom. • There are over 100 different elements.

29. Structure of the Atom • 3 major subatomic particles: • Neutrons. • Protons. • Electrons. • Atomic nucleus – the central core of the atom where the mass is concentrated.

30. Subatomic Particles • Neutron – a heavy subatomic particle that does not have a charge. Located in the atomic nucleus. • Proton – a heavy subatomic particle with a positive charge. Located in the atomic nucleus. • Electron – a light subatomic particle with a negative charge that moves around the outside of the nucleus in energy levels.

32. Atomic Number • All atoms of an element have the same number of protons. • The atomic number of an element is the number of protons in an atom of that element. • Each element has a unique atomic number.

33. Atomic Mass Unit • The mass of a proton is 1.67 x 10-24 grams. • Since this mass is awkward to express, 1 proton is said to have a mass of 1 atomic mass unit (AMU).

34. Neutron Number • All atoms of the same element have the same number of protons and electrons; However, they do not always have the same number of neutrons. They can have more or fewer neutrons. • Each atom of the same element with a different number of neutrons is called an isotope of that element.

35. Atomic Weight • The atomic weight of an element is an average of all the isotopes present in a mixture in their normal proportions.

36. Mass Number • The number of protons and neutrons in the nucleus of an atom is called the mass number.

37. Comparison of Atomic Particles

38. Periodic Table of the Elements • The table provides information about all known elements. • The atomic weight increases as you read left to right along the periods. • Families go from top to bottom and consist of elements with similar chemical properties.

41. 1st Draft of the Periodic Table by Dmitri Mendeleev (1834-1907)

42. Elements in Living Things • 11 main elements comprise living things. • C, H, O, P, K, I, N, S, Ca, Fe, and Mg. • CHOPKINS CaFé, Mighty Good!

43. Position of Electrons • Electrons occupy certain areas around the nucleus known as energy levels. • Each energy level contains electrons movement at about the same speed (approximately the same level of kinetic energy).

44. Position of Electrons • Energy levels are numbered in increasing order with level 1 closest to the nucleus. • Electrons move in spherical or figure 8 patterns around the nucleus. • The first energy level is full when it has 2 electrons, the second energy level is full when it has 8, the third level 8, and so on.

46. Octet (8) Rule • The octet rule states that atoms seek a stable, filled outer energy level. • Hydrogen and Helium have a filled outer energy level with 2 electrons; However, all other atoms have 8 electrons in their outer energy levels.

47. Octet (8) Rule • Atoms attempt to acquire this stable level through chemical reactions with other atoms. • Atoms such as He and Ne have full outermost energy levels. Therefore they normally do not undergo chemical reactions. They are referred to as noble or inert.

49. Valence Shell • The valence shell is the outermost shell of an atom in its uncombined state. • The electrons of the valence shell are the ones that are most likely to contribute to chemical reactions and bond with other atoms. • Electrons in this shell are referred to as valence electrons.

50. Molecule • A molecule is the smallest particle of a chemical compound that is a definite and distinct, electrically neutral group of bonded atoms. • Some atoms bond to form diatomic molecules (di = two). H2, O2, and N2 are diatomic gases in our atmosphere. • Some elements such as the noble gases He and Ne exist as monatomic elements.