II. Introduction and Development: Elements What You Should Know Like the toy blocks that can be put together to form toy structures, elements also join together to form different compounds. Both elements and compounds are pure substances. Compounds such as the water that you drink, are made up of elements, such as hydrogen and oxygen (see Figure 1 and 2). An element cannot be changed into simpler substances. Suppose you heat a piece of gold, thinking that you might stil obtain a simpler substance out of it. But gold is still gold, even after you heated it. No new substance is formed. It is because gold is an element. Therefore, element is the simplest pure substance. As of this writing, there are 118 known elements in the world. You might be familiar with some of them. Iron, used to produce steel, is mainly used in the construction of houses, railways, buildings and other infrastructures. Gold, one of the most precious metallic elements, is used in making fine jewelries. Helium a very light gas, is used to inflate party balloons. 8 A chemical symbol is comprised of one or two letters. The first letter is always capitalized O while the second letter is in lowercase. oxygen The Periodic Table of Elements is a tool (in the form of a table) in which elements are arranged 115.999. 16.000] systematically to show the similarities in properties among the elements. gure 1 Infomanen about an extase the perioden 35 999 Groups are the columns of elements in the periodic table. Elements belong in the same columns belong to the same group. There are 18 groups in the periodic table. Group numbers can be seen at the top of column in the periodic table. 15 20 $ TO Ne B C N Example: Boron (B) and Aluminum belong to group 13. Helium (He), Neon (Ne) and Argon (Ar) all belong to group 18. Carbon (C) belong to group 14. W |-os 23 1 15 13 A AL Si S Ar are Directions: Using a Periodic Table of Elements (pages 86 to 87 of your Science Learner's Material). Write the Symbol of the following elements and its group number. Atomic Number Element Name 1. Silicon Symbol Group Number 2. Gold 3. Calcium 4. Chlorine 5. Platinum​