What has the highest melting point

Understand chemistry 4, textbook

15 Principles of structure of the matter  Learning objective control 4, page 89 3. What do the elements of a group have in common? The eighteen vertical columns in the periodic table are called groups. The two lines below (lanthanides and actinides) belong to the elements of group 3. The elements of a group have the same number of outer electrons and therefore behave similarly in chemical reactions. Element Relationship - LV (Fig. 15.1) A lentil-sized piece of lithium is placed in a small closable (dry!) ​​Tea strainer. The tea strainer is immersed in a beaker filled with water (250ml + 1 drop of washing-up liquid). Lithium dissolves in water and evolves hydrogen gas that can be ignited. The same experiment works with a piece of sodium. Lithium (Li) and sodium (Na) are elements of the 1st group. They each have an outer electron and therefore behave chemically in a similar way. M elements of a group (vertical column) often have similar properties because they have the same number of outer electrons. 4. What can you read in your periodic table? On your periodic table ( page 110) you will find further information on each element about its properties: • The color of the box shows you whether the element is solid, liquid or gaseous at room temperature (20 ° C). • Ordinal number: indicates the number of p + (and e -). • Atomic mass: indicates the number of p + and n 0. The point number results from the fact that not every atom of an element has the same number of n 0. • Oxidation number: indicates how many outer electrons an atom can give off (positive oxidation number) or take up (negative oxidation number). • Melting point and boiling point in ° C • Density in g / cm³ (for gases in g / dm³) at room temperature (20 ° C) • Electronegativity: The lower the electronegativity, the easier external electrons are emitted. • Mass fraction in the earth's crust: How often does the element occur in the earth's crust (including the oceans and the atmosphere)? • Stable or radioactive? Most naturally occurring atoms have stable atomic nuclei. In elements with atomic number 84 or more, the atomic nuclei disintegrate - they are unstable or radioactive. • Artificial elements: some elements do not occur in nature and are manufactured in laboratories. • Necessary for life? The basic elements of life are H, C, N and O. The body needs some other elements in larger quantities. These quantity elements are Na, Mg, P, S, Cl, K and Ca. You need some elements in very small amounts. These trace elements are, for example, Si and Fe. Can you name all of the specified elements? Can you find the rest of the trace elements on your periodic table? Find special items! Which element has the highest melting point and which has the lowest? Which element has the greatest density, which the smallest? Which element is most common or least common in the earth's crust? How many gaseous elements are there? V2 Sodium Na Lithium Li 11p + 3p + 15.2 elements of the same group have the same number of outer electrons. 15.4 The element with the highest melting point glows! 15.3 The trace element zinc (Zn) is particularly found in shellfish and is important for many processes in the body. 15.1 Element relationships For testing purposes only - property of the publisher öbv

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