They used the properties of elements to put each one into groups.
He organized the elements by the order of increasing atomic mass.
They are arranged by increasing atomic number
The three classes are metals, nonmetals, and metalloids.
B, because they all belong to the earth metal groups
Gold=metal, silicon=metalloid, sulfur=nonmetal, barium=metal
Potassium and lithium
167 (#’s 8–9)
Carbon= 1s^2 2s^2 2p^2, strontium= 1s^2 2s^2 2p^6 3s^2 3p^6 3d^10 4s^2 4p^6 5s^2 vanadium= 1s^2 2s^2 2p^6 3s^2 3p^6 3d^3 4s^2
Boron, fluorine, vanadium
page 167 (#‘s 10–11) and (#’s 12–15 odd)
The table displays the names of elements also the structure of the atoms
Elements are separated into noble gases, representative elements, transition metals, and inner transition metals.
noble gas, representative element, representative metal
page 178 (#’s 16–23) 16. The atomic size increases from top to bottom but it decreases by group from left to right. 17. Ions form when electrons transfer between atoms.
18. In first ionization the energy decreases from top to bottom but increases left to right in a group.
19. Cations are smaller, anions are larger.
20. Electronegativity decreases from top to bottom and increases left to right.
21. The trends are explained by variation in atomic structure.
22. Chlorine, SUlfur, Aluminum, and Sodium
23. Sodium; Phosphorous
pages 181–184 (#’s 24, 27, 29, 31, 33, 35, 37, 40, 43, 47, 51, 54, 60, 62, 68, 70–86) 24. Because then undiscovered elements could be placed in the same group 27. The properties of gallium are what gained a stronger acceptance of Mendeleev's periodic table 29. They have properties similar to metals and nonmetals, although behavior depends on the conditions. 31. Na, Mg, Cl 33. aluminum 35. Ar: 1s^2 2s^2 2p^6 3s^2 3p^6; Si: 1s^2 2s^2 2p^6 3s^2 3p^2; Mg: 1s^2 2s^2 2p^6
37. The energy is used to remove an electron from an atom. The second ionization energy is the energy used to remove the second electron.
40. It is easy to remove the first electron, but harder to remove the second from an alkali metal 43. F, N, Mg, As 47. A. 18011850 B Mendeleev's table helped