Funny Elements (He, He, He) What is Cesium and Iodine’s favourite tv show? Know any jokes about Sodium? What do you call a silly prisoner?

UNIT TEST – Read Outline, define terms, Complete questions using your notes. Correct answers by checking the portal. Additional Test Review: p. 288 – , 42, 55, 56, 57, 63, 64, 65, p. 250 – 251 #1-10, 12, 13, 14, 19, 20 Remember to use your notes to answer questions. Check your answers with the back of the book.

5. Explain the difference between the following: An element is a pure substance made of one type of atom. A compound is a pure substance made of 2 or more different atoms chemically combined. A group is a vertical column in the periodic table. A row is a horizontal row in the periodic table. A metal is an element that is usually silver, solid at room temp. conducts heat and electricity, is malleable, ductile and lustrous. A non-metal exists in different colours and states, does not conduct electricity and heat and is not malleable, ductile or lustrous. A proton is a positively charged particle. A neutron is a neutral particle and has no charge. They are both found in the nucleus. An electron is a negatively charged particle found outside the nucleus in energy shells.

6. Explain the similarities and differences between the plum pudding model and the Bohr model of the atom. Plum Pudding (Thompson) – believed that the atoms contained negatively charged electrons found throughout a positively charged atom. Bohr found evidence to support that electrons orbited the nucleus of the atom like planets orbit the sun. Each orbit holds a certain number of electrons.

13. Elements in the same family (alkaline Earth Metals – silver, lustrous, reactive) Elements in the same period have the same number of energy shells. Elements in the family of noble gases are gases, odourless, colourless and inert (unreactive).

15. The alkali metals are highly reactive. This is because they have 1 valence electron. In order to become stable they only have to lose 1 valence electron which happens easily making them highly reactive. Halogens have 7 valence electrons. To become stable Halogens gain 1 electron. This happens easily making them highly reactive. Noble gases have 2 or 8 valence electrons. Since they have a full set of electrons they don’t need to gain or lose electrons and are inert (unreactive).

19. Thinking The most reactive solid is C (bubbled vigorously). The least reactive is B (no change).

I think these elements are Metals because they have metallic lustre. I think these elements belong in group 2, the Alkaline Earth Metals. Solid B did not react with water or acid. All alkali metals are reactive with water, therefore these elements cannot belong to Group 1, the Alkali Metal group. Solid A and C did react with water and/or acid showing that these elements are reactive. Alkaline Earth Metals are not as reactive as Alkali Metals.

Reactivity increases as you move down a metallic family. It becomes easier to lose the valence electron and therefore the elements become more reactive. Solid B did not react at all and is the least reactive. It would be the highest in the family. Solid A would be next, and Solid C would be at the bottom because it reacted with water and acid making it the most reactive.

p. 282 #1-7, 9, 10, 11, 13, 14, 15, 20, Noble gases are the most stable elements because they have a full set of valence electrons. They don’t need to gain or lose electrons to become stable. 14. All molecules are not considered compounds because some molecules are elements. Many elements exist as molecules such as O 2, H 2, Cl 2. These are called diatomic molecules because they exist as 2 atoms bonded together.

15. Potassium reacts with Chlorine. Show the formation of the compound. Potassium is a metal. Chlorine is a nonmetal. A metal and a nonmetal make an ionic compound. In an ionic compound electrons are transferred. Potassium will lose its valence electron and chlorine will gain the electron to complete its outer shell. Draw out each bohr-Rutherford diagram. Look in the textbook or in your notes for examples. Show the transfer of the electron. Draw each Atom with it’s new charge and complete outer shell.

b)A chloride ion has 17 protons, how many electrons does it have? Chlorine is element number 17, therefore it has 17 electrons and protons. If it is an ion, it has gained an electron and therefore has 18 electrons. c) A potassium ion has 19 protons, how many electrons does it have? Potassium is an alkali metal and therefore loses an electron. This means that it has 18 electrons and a charge of positive 1.

20. Beryllium and Fluorine make an ionic compound. How do we know? Beryllium is a metal and Fluorine is a nonmetal. Beryllium must lose 2 electrons and Fluorine needs to gain 1 electron. When they react, we need 1 Berylllium and 2 Fluorine atoms. 22.How is the bonding different – One is a molecular element in which electrons are shared. One is an ionic compound in which electrons are transferred.