Regents Earth Science. Lab &: Elements / Minerals

Transcription

1 Name Date Regents Earth Science Period Lab &: Elements / Minerals Question: What is the relationship between elements and minerals? Introduction: (you will need the ESRT to complete this lab) Below is a pie chart of the most abundant elements in the Earth s crust. You will use the data from the pie chart to create a table below. List the elements from the MOST abundant to the least. Then answer the questions on the next page. Element Symbol Percentage by Mass in Earth s Crust 1

2 Answer all Questions in complete sentences (except # 1 and 6) 1. Where can you find a similar table to your on the ESRT? 2. How is your table similar to or different from the ESRT table? 3. The first eight elements listed in your table together make up what percentage of the Earth s crust? 4. Which element is the most abundant? 5. Which element is the second most abundant? 6. Together oxygen and silicon make up what percentage of the Earth s crust? 7. There are only 92 naturally occurring elements in the Earth s crust; however there are over 2,500 minerals. Explain how this can be possible. 8. The elements gold, silver and platinum are called precious metals. One meaning of precious is of great value or high price. Why do you think these metals are so costly? 2

3 Part II: Silicate Minerals Many from a Few P 1 The Earths crust is made up of many different elements. However a random sampling of soil would contain mainly the elements oxygen and silicon. Most of the remaining portion of the sample would contain the metallic elements aluminum, iron, calcium, sodium, magnesium, and potassium. The minerals formed for a combination of oxygen, silica and some metals are members of the family called silicates. P2 Elements combine to form over 2,000 different types of minerals. About 92% of these minerals are made from oxygen and silicon atoms. If most minerals are made up of these 2 atoms, you might expect all minerals to look alike. However, two common silicates, quartz and mica do not look alike at all. P3 Also, feldspar minerals (a type of silicate) are divided into 2 groups: potash feldspar which breaks at right angles when it fractures, and plagioclase, which breaks at angel less than 90 o. How can there be so many varieties of minerals if there are only 2 major building blocks? The answer lies in the way the atoms are arranged. Different atomic arrangement is what causes the minerals to look so different. P4 The smallest unit of a mineral, or molecule, found in silicate minerals contains 1 silicon and 4 oxygen atoms. These 5 atoms form the four triangular sides of a silica tetrahedron. In the simplest cases, a silicon atom links tetrahedrons together to form a single chain. Metal atoms can also serve as the link between single-chain tetrahedrons. In addition, silica tetrahedron can either form double chains or appear in sheets. Quartz is made entirely of tightly bonded single chains. 3

4 Feldspar is made of single chains joined mostly by Aluminum. Mica is formed from a sheet like grouping of tetrahedrons. The different way of arranging these few element form the variety of minerals found all over the Earth. 1. What are silicate minerals? 2. How are the atoms arranged in a silica tetrahedron? 3. Why don t silicate minerals all look alike? Elements & Minerals: ESRT Practice 1. Name the two elements that are most abundant in the Earth s crust: 4

5 2. Elements are found in (equal/unequal) amounts in the Earths crust. (circle one) 3. Which of the minerals listed in the ESRT are silicates? 1) 6) 2) 7) 3) 8) 4) 9) 5) 10) 4. Which element is found in the crust, hydrosphere and the troposphere? 5. Minerals are made from elements. Predict 2 elements found in most minerals. 6. Minerals are found in equal / unequal) amounts in the Earth s crust. (Circle one). Explain: 7. Mixtures of minerals are called. 8. From ESRT page 6, Scheme for Igneous Rock identification, determine and list the names of the minerals found in Granite. 1) 4) 2) 5) 3) 9. List the minerals found in Basalt. 1) 3) 2) 4) 5