calcium and magnesium

Transcription

1 Section 5 5 Elements and the Periodic Table (Pages ) 1. Electrolytes are the substances whose water solutions conduct electricity. Nonelectrolytes are substances that when in water do not conduct electricity. 2. The Periodic Table is structured arrangement of elements that help to explain and predict physical and chemical properties. 3. Metals can be found on the left side of the periodic table. Two examples are. calcium and magnesium Nonmetals can be found on the right side of the periodic table. Two examples are. chlorine and oxygen 4. Metalloids are substances on the periodic table that have both metal and nonmetal properties. The Metalloids on the periodic table include;, boron, aluminum, silicon, germanium, arsenic, antimony, tellurium, polonium. astatine (think staircase)

2 shiny malleable conductors mostly yes mostly solids dull brittle mostly insulators no solids, liquids, gases

3 6. Chemical families are groups of elements in the same vertical column of the periodic table. They tend to have similar physical and chemical properties. 7. The elements of Group 1 are called. alkali metals They are shiny,, silvery metals. They form compounds that are mostly white soli and are very soluble in. water alkaline earth metals 8. The elements of Group 2 are called. These elemen are shiny, silvery metals. They form compounds that are often insoluble in. water 9. The elements in the far right column (group 18) are called the noble gases They do not form compounds. 10. The elements of Group 17 are called the. halogens They are poisonous elements that react readily with sodium and other alkali metals. The elements in Group 16 are called CHALOGENS. The LANTHANIDES are the elements from # The ACTINIDES are the elements from #

4 11. The three subatomic particles are:, protons, electrons and. neutrons 12. Protons are positively charged particles that are found in the. nucleus The number of protons is equal to the atomic number 13. Neutrons are neutral particles that are found in the nucleus. 14. Electrons are negatively charged particles with a very small mass and circle around the nucleus. 15. Orbits are the energy levels where electrons travel. 16. The valence shell is the outer shell of the atom. This is where the outer electrons or valence electrons are found. (box page 186) 17. The farther away an electron is from the nucleus the greater its energy level. These electrons will be involved in chemical changes. 18. Bohr diagrams are used to represent the arrangement of electrons in various orbits. In Bohr models, the maximum number of electrons in the first energy level is 2. The maximum number of electrons in the second energy level is 8. The maximum number of electrons in the third energy is 18. However, when we draw a Bohr diagram we can have 8 electrons in the third energy level. 19. An ion is a charged atom in which the number of electrons is different from the number of protons. The ionic charge is the numerical value of the electric charge with a plus or minus sign. 20. Metals tend to lose electrons when they combine with other elements to form positive ions. 21. Nonmetals tend to gain electrons when they combine with other elements to form negative ions. cations 22. Positive ions are also called. Negative ions are also called. anions (page 187 in the box)

5 Something to think about: The number of protons in an atom NEVER changes. In a neutral atom, the number of protons the number of electrons. If an atom has more electrons than protons, the ion will have a charge. If an atom has more protons than electrons, the ion will have a charge. Negative ions have an IDE ending. equals negative positive

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