Question

periodic table - periods, groups, families of elements, lewis diagrams
periods - rows of elements; the period an element is in indicates the # of energy levels it has
groups - columns of elements; group a (representative elements) and group b (transition elements)
group a elements - group # indicates #ve- in the outermost energy level; similar chemical properties

1. fill in the blank with either the group # or the name of the family of elements.

group 2a
halogens
group 8a
group 1a

1. which elements are not semi - metals/metalloids?

circle all that apply.
a. li e. at
b. si f. n
c. c g. te
d. sb h. al

1. which element has similar chemical properties as oxygen?

a. n
b. li
c. s
d. cl

1. the modern periodic table has elements arranged by

a. atomic mass
b. atomic number
c. valence electrons
d. number of isotopes

1. indicate the number of valence electrons each element has.

a. strontium
b. argon
c. cesium
d. bromine
e. phosphorus
f. carbon

Explanation:

1. Uses standard periodic table family/group names. Group 2A are alkaline earth metals; halogens are Group 7A; Group 8A are noble gases; Group 1A are alkali metals.
2. Identifies non-metalloids: Li is alkali metal, At is halogen/non-metal, N is non-metal, C is non-metal, Si is metalloid, Te is metalloid, Sb is metalloid, Al is metal.
3. Elements in the same group (Group 16) as oxygen have similar properties; sulfur (S) is in Group 16.
4. Modern periodic table is ordered by increasing atomic number, which defines element identity.
5. Valence electrons are determined by group number for main-group elements: Group 2A (Sr) has 2; Group 8A (Ar) has 8; Group 1A (Cs) has 1; Group 7A (Br) has 7; Group 5A (P) has 5; Group 4A (C) has 4.

Answer:

22.
Group 2A: Alkaline Earth Metals
Halogens: Group 7A
Group 8A: Noble Gases
Group 1A: Alkali Metals

23.
A. Li, E. At, F. N, C. C, H. Al

24.
C. S

25.
B. atomic number

26.
A. strontium: 2
B. argon: 8
C. cesium: 1
D. bromine: 7
E. phosphorus: 5
F. carbon: 4