2. Chemistry Chemical Interactions Ch. 1

3. Bell Work 11/17/09 1.What is matter? 2.What are the three states of matter? 3.What is an atom?

4. Matter – is anything that has mass and takes up space. MATTER is never created or destroyed, it only changes form.

5. Atoms – The basic building blocks of all the substances in the universe. All things are made up of atoms. http://science.howstuffworks.com/nanotechn ology1.htm

6. Elements – Are made of one kind of atom grouped together and cannot be broken down into simpler substances. 1.Identical atoms make up elements 2. 110 elements make up all the known substances on earth!!!

7. Atoms contain one or more PROTONS, NEUTRONS, and ELECTRONS

8. Protons and neutrons make up the nucleus of an atom. Electrons “float” around the nucleus of an atom. nucleus Electrons

9. Protons – Particles that have a positive electric charge. Neutrons – have no electric charge. Electrons – Particles with a negative charge located outside of the nucleus.

10. The nucleus of the atom is positively charged (+). The negatively (-) charged electrons surround the nucleus to balance the charge of the atom to neutral. – The number of protons equals the number of electrons.

11. Atomic number – the number of protons in an atom. Found above the element symbol. Mass number – is equal to the number of protons plus the number of neutrons. The number of neutrons is determined by subtracting the atomic number from the mass number.

12. Bell Work 11/18/09 Find the atomic number and average atomic mass of the following elements: 1.Calcium 2.Barium 3.Selenium 4.Gold Find the number of protons, electrons, and neutrons for the following elements: 5. Phosphorus 6. Lithium

13. Special atoms The number of protons always stays the same, however sometimes the number of neutrons or electrons changes. Electrically Stable – atoms that have no electric charge

14. Special Atoms Isotopes – atoms of the same element that have different numbers of neutrons. Examples Chlorine – 35Chlorine - 37

15. Special Atoms Ions – formed when an atom loses or gains one or more electrons Lose 1 electron becomes + ion Gain 1 electron becomes - ion

16. Bell Work 11/19/09 Determine the name of each isotope 1.Protons = 62. Protons = 20 Neutrons = 7 Neutrons = 22 Determine the name of each ion 3. Protons = 74. Protons = 5 Electrons = 9 Electrons = 3

17. Bell Work 11/20/09 Determine if each is an ion, isotope, or electrically stable and name the element 1.Protons = 113. Protons = 18 Neutrons = 11 Neutrons = 22 Electrons = 11 Electrons = 20 2. Protons = 104. Protons = 21 Neutrons = 10 Neutrons = 20 Electrons = 9 Electrons = 21

18. The number in the right corner of each element represents the amount of protons that element has……thus the amount of electrons.

19. Groups – are the numbers at the top of the periodic table that represent the number of electrons in the outermost shell (energy level). Periods – the number to the left of the periodic table that represents the number of shells an element will have.

20. Group number Period number

22. Bell Work 11/23/09 Draw each of the following elements. Be sure to put the correct number of protons and neutrons in the nucleus. 1.Oxygen 2.Sodium 3.Silicon 4.Lithium

23. 1.Electrons circle around the nucleus in shells or energy levels. 2.As an element looses an electron it looses energy and as an element gains electrons it gains energy. 3.Each circle or shell is limited to how many electrons it can hold.

24. Valence electrons – electrons in the outermost energy level of an atom. The valence shell can have 1 to 8 electrons in it depending on its place on the periodic table. Elements to the left have 1 and elements to the right have 8.

25. Electrons in valance shells that are not full will either gain electrons to become full or give up electrons allowing its outer shell to be lowered to its next lowest level (which is full).