# 3.2: A Brief History of the Organization of the Periodic Table (Problems)

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PROBLEM $$\PageIndex{1}$$

Using the periodic table, classify each of the following elements as a metal or a nonmetal, and then further classify each as a main-group element, transition metal, or inner transition metal:

a. uranium
b. bromine
c. strontium
d. neon
e. gold
f. americium
g. rhodium
h. sulfur
i. carbon
j. potassium

metal; inner transition metal

nonmetal, main group element

metal, main group element

nonmetal, main group element

metal, transition metal

metal, inner transition metal

metal, transition metal

nonmetal, main group element

nonmetal, main group element

metal, main group element

PROBLEM $$\PageIndex{2}$$

Using the periodic table, classify each of the following elements as a metal or a nonmetal, and then further classify each as a main-group (representative) element, transition metal, or inner transition metal:

a. cobalt
b. europium
c. iodine
d. indium
e. lithium
f. oxygen
h. terbium
i. rhenium

metal, transition metal

metal, inner transition metal

nonmetal, main group element

metal, main group element

metal, main group element

nonmetal, main group element

metal, transition metal

metal, inner transition metal

metal, transition metal

PROBLEM $$\PageIndex{3}$$

Using the periodic table, identify the lightest member of each of the following groups:

a. noble gases
b. alkaline earth metals
c. alkali metals
d. chalcogens

He

Be

Li

O

PROBLEM $$\PageIndex{4}$$

Using the periodic table, identify the heaviest member of each of the following groups:

a. alkali metals
b. chalcogens
c. noble gases
d. alkaline earth metals

Fr

Po

Rn

Ra

PROBLEM $$\PageIndex{5}$$

Use the periodic table to give the name and symbol for each of the following elements:

(a) the noble gas in the same period as germanium
(b) the alkaline earth metal in the same period as selenium
(c) the halogen in the same period as lithium
(d) the chalcogen in the same period as cadmium

Kr; Krypton

Ca; Calcium

F; Fluorine

Te; Tellurium

PROBLEM $$\PageIndex{6}$$

Use the periodic table to give the name and symbol for each of the following elements:

(a) the halogen in the same period as the alkali metal with 11 protons
(b) the alkaline earth metal in the same period with the neutral noble gas with 18 electrons
(c) the noble gas in the same row as an isotope with 30 neutrons and 25 protons
(d) the noble gas in the same period as gold

Cl; Chlorine

Mg; Magnesium

Kr; Krypton

PROBLEM $$\PageIndex{7}$$

Write a symbol for each of the following neutral isotopes. Include the atomic number and mass number for each.

(a) the alkali metal with 11 protons and a mass number of 23
(b) the noble gas element with and 75 neutrons in its nucleus and 54 electrons in the neutral atom
(c) the isotope with 33 protons and 40 neutrons in its nucleus
(d) the alkaline earth metal with 88 electrons and 138 neutrons

$$\ce{^{23}_{11}Na}$$

$$\ce{^{129}_{54}Xe}$$

$$\ce{^{73}_{33}As}$$

$$\ce{^{226}_{88}Ra}$$

PROBLEM $$\PageIndex{8}$$

Write a symbol for each of the following neutral isotopes. Include the atomic number and mass number for each.

1. the chalcogen with a mass number of 125
2. the halogen whose longest-lived isotope is radioactive
3. the noble gas, used in lighting, with 10 electrons and 10 neutrons
4. the lightest alkali metal with three neutrons

$$\ce{^{125}_52Te}$$

$$\ce{^{210}_85At}$$

$$\ce{^{20}_10Ne}$$
$$\ce{^{6}_3Li}$$