Ch1 chem 09.notebook April 15, 2015

Transcription

1 Chemistry needs: magnets paperclips Br Chem Explore activity Ch1 sec. 1 Obtain a magnet and a few paper clips Build a model that simulates electrons being held within an atom. Show that electrons closer to the nucleus will have less energy. O C O O Also show that electrons farther from the nucleus have more energy to move and can easily be removed. Sec. 1 Ch 1 Date Objective: Identify how electrons are arranged in an atom. Draw a model of an atom show - electron cloud, protons, neutrons, electrons, nucleus. pg.9 perspective: If the nucleus of the atom were the size of a penny the electrons would be smaller than a grain of dust and the electron cloud would extend as far as 20 football fields. element pure substance made of one type of atom. atom smallest part of an element and still keep its identity compounds two or more different atoms in chemical combination molecule is the smallest part of a compound or atoms joined together. Understanding the Periodic Table The atomic # = the number of protons in an atom # of protons = # of electrons in a neutral atom. charge Energy levels - different positions electrons tend to be in, in the electron cloud. neutral

2 A. General structure of atoms pg Each element has a different atomic structure with a specific number of protons, neutrons, and electrons 2. The number of protons and electrons is always the same for a neutral atom. B. Nucleus 1. contains protons and neutrons a. protons positively charged particles in the atom b. neutrons have neutral charge. c. nucleus, thus has a positive charge d. the size of the nucleus determines the mass of the atom. 1. contains electrons of the atom held in differnt energy levels a. energy levels pg each energy level can hold a specific number of electrons. 2. the farther away the level is from the nucleus the more electrons it can hold. 3. electrons in the level closest to the nucleus have the lowest amount of energy 4. farther from the nucleus electrons have more energy and more easily move. Diagram in book Atomic Energy Levels Each energy level can hold a given number of electrons level closest to nucleus - energy level 1-2 electrons level 2-8 electrons level 3-18 electrons level 4-32 Electrons in the level closest to the nucleus have the Lowest amount of energy. ex. Ar has 18 electrons, O has 8

3 Families of the Periodic Table carbon C nitrogen N electron dot diagram of outer shell electrons Columns of the periodic table are called Rows groups, also called families. Elements of the same family have similar characteristics. videos are called periods. periodic table elements explaned Major Element Families 1. Noble Gas Neon and the elements below it in Group 18 have 8 electrons in their outer energy level. Their energy level is stable, so they do not combine easily w/other elements. What group are halogens in? 2. Halogens Page 12 - the reactivity decreases towards the outer layer of the atom. -atoms with electrons in farther energy levels are less reactive - found in group 17 F, Cl, Br What group are alkali metals in? 3. Alkali Metals -form compounds that are similar to each other -larger atoms are more reactive than smaller ones Complete the problem solving activity on pg. 13 Do not ask for help from your neighbor!

4 Answers to Problem Solving pg. 13 pg magnesium 2. oxygen 3. group sulfur, selenium, tellurium Electron Dot Diagrams With your assigned group complete the mini lab on page 14. Follow the directions exactly in the reading on pg. 14 Make sure everyone in the group understands how to make a dot diagram. i Virtual Lab Atom Formation Scientific Methods Brain Pop Video Section 1 Self Check Quiz Section 2 Self Check Quiz Chapter 1 Chemical Bonds Test Practice Chapter 1 Review Quizzes Eng.

5 section 1 review answers 1. 5, , 6 3. second 4. same # of electrons in outer level, tell us how they react with other elements plus.blogspot.com/2011/01/atoms and their electrons.html atoms and their electrons 30 min story Section 2 How Elements Bond A union between elements How Romantic It's True Love ch1 sec.2 pg. 17 Atoms form bonds with other atoms using the electrons in their outer energy levels. 4 Ways Atoms Form Bonds pg losing electrons 2. gaining electrons 3. pooling electrons 4. sharing electrons compound (FC) a pure substance containing 2 or more elements that are chemically bonded. H 2 O O 2 is a compound is a molecule *not a compound only one element type draw example its charge? If Na loses an electron what happens to Ion (fc) An atom that is no longer neutral because it has lost or gained an electron. example: Chlorine and Sodium pg Ionic Bond (fc) - when two ions are opposite in charge are held closely together. pg. 17 Ionic Bond understand how losing and gaining of electrons change charge of the atom Draw ex. pg 17 Na + Cl sodium and water 2Na(s) + 2H2O 2NaOH(aq) + H2(g) A colourless solution is formed, consisting of strongly alkalic sodium hydroxide (caustic soda) and hydrogen gas. This is an exothermic reaction. Sodium metal is heated and may ignite and burn with a characteristic orange flame. Hydrogen gas released during the burning process reacts strongly with oxygen in the air. A number of sodium compounds do not react as strongly with water, but are strongly water soluble. Read more: and water/sodium and water.htm#ixzz0qtanlzvx < and water/sodium and water.htm> animated reaction of sodium and water siegen.de/~pci/versuche/english/v html

6 lab Four types of Bonds 1. Ionic bonds The strong attraction, due to opposing charge, that holds positive and negative ions close together Mg O examples of 2+ gains or loses pg. 18 Mg O Cl Mg Cl 2. Metallic Bonding (Pooling) (FC) metal atoms share their pooled electrons outer electrons move freely from atom to atom in metals. (shared pool of electrons) metals can bend, stretch, and conduct electricity due to this pooling of electrons Covalent bonds (sharing) (FC) a bond that forms between atoms that share electrons pg. 19 diagram A&B Ionic and covalent bonding animation Polar covalent bonding simulated in water interactive covalent bond

7 2H 2 O 2 How many elements? 2 elements H hydrogen O Oxygen How many atoms of each element? H 4 O 4 4. Polar bonds (form of covalent) (FC) bond resulting from unequal sharing of electons Compound Review How many atoms of each element? How many elements

8 For test Friday Review all vocab ch. 1 understand how to read the periodic table and give information about total and outer electrons from it. be able to diagram the electron configuration of any atom that is number Know properties of the element families be able to model the parts of an atom and the respective charges of particles. tell me how many electrons and protons are in any neutral atom on the periodic table. give info about a chemical formula how many atoms, elements etc. If given atoms of an ionic bond tell me how they are bonded. Be able to write the ionic formula with positive and negative charges beside the atom symbol (this was done in lab) Define the different ways atoms bond. and what a polar molecule is. Label the diagram of the atom Nucleus { Electrons Protons for the answer Neutrons Which of these statements is correct? Which of these statements is correct? 1. Atoms are made up of electrons, neutrons and protons. 1. Electrons are positively charged 2. Atoms do not contain electrons but they do contain protons and neutrons. 2. Neutrons do not weigh anything 3. Atoms never contain neutrons for the answer 3. Protons are found inside the nucleus for the answer

9 The following pages are answers to the tasks in the lesson activity. The structure of an atom The correct statement is... Nucleus { Electrons Neutrons 1. Atoms are made up of electrons, neutrons and protons. 2. Atoms do not contain electrons but they do contain protons and neutrons. Protons to go back 3. Atoms never contain neutrons to go back The correct statement is Electrons are positively charged 2. Neutrons do not weigh anything 9/5/08 polar bond chemical shorthand Each element has a one or two letter naming system, first letter is capital second would be small the number or atoms of each element is represented with a script number. Cl 4 Chemical Formula (fc) 3. Protons are found inside the nucleus to go back

10 covalent electron cloud molecule gain or loss of electrons nucleus