groups of elements

group 2 alkaline earth metals

The alkaline Earth metals include all the elements in group 2 (see Figure 6.10). These metals have just two valence electrons, so they are very reactive, although not quite as reactive as the alkali metals. In nature, they are always found combined with other elements. Alkaline Earth metals are silvery grey in color. They are harder and denser than the alkali metals. All are solids at room temperature.

groups 312 transition metals

Groups 3-12 of the periodic table contain transition metals (see Figure 6.11). Transition metals have more valence electrons and are less reactive than metals in the first two metal groups. The transition metals are shiny. Many are silver colored. They tend to be very hard, with high melting and boiling points. All except mercury (Hg) are solids at room temperature. Transition metals include the elements that are placed below the periodic table. Those that follow lanthanum (La) are called lanthanides. They are all shiny, relatively reactive metals. Those that follow Actinium (Ac) are called actinides. They are all radioactive metals. This means they are unstable. They break down into different, more stable elements. You can read more about radioactive elements in the chapter Nuclear Chemistry. Many of the actinides do not occur in nature but are made in laboratories.

textbook_image

textbook_image

group 1 hydrogen and alkali metals

All the elements in group 1 have just one valence electron, so they are highly reactive. Group 1 is shown in Figure element in the universe. All the other elements in group 1 are alkali metals. They are the most reactive of all metals, and along with the elements in group 17, the most reactive elements. Because alkali metals are so reactive, they are only found in nature combined with other elements. The alkali metals are soft. Most are soft enough to cut with a knife. They are also low in density. Some of them even float on water. All are solids at room temperature. You can see a video demonstrating the reactivity of alkali metals with water at this URL: (2:22). MEDIA Click image to the left or use the URL below. URL:

textbook_image

group 18 noble gases

Group 18 elements are nonmetals called noble gases (see Figure 6.14). They are all colorless, odorless gases. Their outer energy level is also full, so they are the least reactive elements. In nature, they seldom combine with other substances. For a short video about the noble gases and their properties, go to this URL:

groups 1316 groups containing metalloids

Groups 13-16 each contain one or more metalloids. These groups are shown in Figure 6.12. Group 13 is called the boron group. The only metalloid in this group is boron (B). The other four elements are metals. All group 13 elements have three valence electrons and are fairly reactive. All are solids at room temperature. Group 14 is called the carbon group. Carbon (C) is a nonmetal. The next two elements are metalloids, and the final two are metals. All the elements in the carbon group have four valence electrons. They are not very reactive. All are solids at room temperature. Group 15 is called the nitrogen group. The first two elements in this group are nonmetals. These are followed by two metalloids and one metal. All the elements in the nitrogen group have five valence electrons, but they vary in their reactivity. Nitrogen (N) in not reactive at all. Phosphorus (P), in contrast, is quite reactive. In fact, it is found naturally only in combination with other substances. Nitrogen is a gas at room temperature. The other group 15 elements are solids. Group 16 is called the oxygen group. The first three elements in this group are nonmetals. They are followed by one metalloid and one metal. All the elements in the oxygen group have six valence electrons, and all are

textbook_image

group 17 halogens

Elements in group 17 are called halogens (see Figure 6.13). They are highly reactive nonmetals with seven valence electrons. The halogens react violently with alkali metals, which have one valence electron. The two elements combine to form a salt. For example, the halogen chlorine (Cl) and the alkali metal sodium (Na) react to form table salt, or sodium chloride (NaCl). The halogen group includes gases, liquids, and solids. For example, chlorine is a gas at room temperature, bromine (Br) is a liquid, and iodine (I) is a solid. You can watch a video demonstrating the reactivity of halogens at this URL: .

instructional diagrams

No diagram descriptions associated with this lesson

questions

column of elements in the periodic table

a. alkali metal

b. alkaline Earth metal

c. halogen

d. noble gas

e. transition metal

-->  f. group

g. actinide

Hydrogen is in the same group as the alkali metals because

a. it is a metal.

b. it is unreactive.

-->  c. it has one valence electron.

d. it is in period 1 of the periodic table.

element in group 18 of the periodic table

a. alkali metal

b. alkaline Earth metal

c. halogen

-->  d. noble gas

e. transition metal

f. group

g. actinide

Alkaline Earth metals are less reactive than

a. noble gases.

b. transition metals.

-->  c. alkali metals.

d. all of the above

metal in group 1 of the periodic table

-->  a. alkali metal

b. alkaline Earth metal

c. halogen

d. noble gas

e. transition metal

f. group

g. actinide

Which groups of the periodic table contain one or more metalloids?

a. groups 12

b. groups 312

-->  c. groups 1316

d. groups 1718

The most reactive nonmetals are elements in the

a. boron group.

b. nitrogen group.

c. oxygen group.

-->  d. halogen group.

radioactive transition metal

a. alkali metal

b. alkaline Earth metal

c. halogen

d. noble gas

e. transition metal

f. group

-->  g. actinide

metal in group 2 of the periodic table

a. alkali metal

-->  b. alkaline Earth metal

c. halogen

d. noble gas

e. transition metal

f. group

g. actinide

All elements in the carbon group

a. are solids are room temperature.

b. have four valence electrons.

c. are not very reactive.

-->  d. all of the above

metal in group 3 of the periodic table

a. alkali metal

b. alkaline Earth metal

c. halogen

d. noble gas

-->  e. transition metal

f. group

g. actinide

nonmetal in group 17 of the periodic table

a. alkali metal

b. alkaline Earth metal

-->  c. halogen

d. noble gas

e. transition metal

f. group

g. actinide

Elements in group 1 include

a. hydrogen.

b. alkali metals.

c. alkaline Earth metals.

-->  d. two of the above

Alkali metals are

-->  a. soft.

b. high in density.

c. not very reactive.

d. all of the above

Which statement about alkaline Earth metals is true?

a. They are more reactive than alkali metals.

-->  b. They are always found combined with other elements.

c. Some of them are liquids at room temperature.

d. They are all gold in color.

The most reactive metals are the transition metals.

a. true

-->  b. false

Transition metals tend to

-->  a. be shiny.

b. boil at low temperatures.

c. be very soft.

d. be extremely reactive.

Alkaline Earth metals have three valence electrons.

a. true

-->  b. false

The only nonmetal in the carbon group is

a. nitrogen.

b. boron.

-->  c. carbon.

d. oxygen.

Halogens form salts when they combine with

-->  a. alkali metals.

b. alkaline Earth metals.

c. transition metals.

d. all metals.

Mercury is the only metal that is a liquid at room temperature.

-->  a. true

b. false

Nobles gases are

a. colorless.

b. odorless.

c. reactive.

-->  d. two of the above

Boron is an example of an element in the metalloids class.

-->  a. true

b. false

Helium is an element in the group called the halogens.

a. true

-->  b. false

Hydrogen is an alkali metal.

a. true

-->  b. false

Alkali metals are found only in compounds.

-->  a. true

b. false

Some alkali metals can float on water.

-->  a. true

b. false

Calcium is an alkali metal.

a. true

-->  b. false

There is just one group of transition metals.

a. true

-->  b. false

Many of the actinides do not occur in nature.

-->  a. true

b. false

Elements in the oxygen group have eight valence electrons.

a. true

-->  b. false

Selenium is an alkaline Earth metal.

a. true

-->  b. false

The halogen group includes only gases.

a. true

-->  b. false

Noble gases are found only in combination with other elements.

a. true

-->  b. false

diagram questions

No diagram questions associated with this lesson