Need help answering the following multiple choice questions (see attachment)
They are based on the â??The Essential Earthâ? book by John Grotzinger, 1st edition
I think that the book â??Earth Scienceâ? by Edward J. Tarbuck is compatible for this questions.
Often mineralogy class starts with the definition of a mineral: a naturally occurring solid, with a definite internal structure and a fixed chemical composition. To explain this definition, take for example the silicate class of minerals, which make up a large part of the earth's crust. The fundamental unit of all silicate structure is the silicon tetrahedron (SiO4) where you have four oxygen ions (2-) at the apices of a regular tetrahedron surrounding and coordinated by the silicon ion (4+) (Silicon atom has the atomic number 14 meaning it has 14 protons and oxygen has the atomic number 8). Silicates are further divided into several classes based on the arrangement of the tertahedra. For example, the tectosilicate class has the silicon tetraherdon arranged in a three-dimensional network where all the oxygen ions are linked together while in the phyllosilicate class the silicon tetrahedra are linked into sheets. The arrangement of atoms give the mineral an internal structure reflected in an outward appearance called form. The crystal faces that make up the form are more defined in a well grown crystal. Identification of minerals is based on its chemical and physical properties - properties dependent on the composition and arrangement of atoms. Physical properties such as cleavage and hardness reflect the internal structure and are useful for identification. Color, which results from how white light strikes the mineral, is constant in some minerals but may be affected by impurities and surface alteration. The color of the metallic mineral chalcopyrite (CuFeS2), an important ore mineral of copper, is commonly brass-yellow but it can tarnish to bronze. Streak, the color of finely powdered mineral is usually constant although color may vary. Minerals can be grouped based on similar properties. The feldspars, for example, are aluminosilicates (with potassium, sodium, and calcium) which ...