Chemistry Chapter 6

Which of these sets of elements have similar physical and chemical properties? a. oxygen, nitrogen, carbon, boron b. strontium, magnesium, calcium, beryllium c. nitrogen, neon, nickel, niobium

B: strontium, magnesium, calcium, beryllium

What elements end with the following configuration: ns2 np1

Boron, Aluminum, Gallium, Indium, Thallium

Into what four classes can elements be sorted based on their electron configurations?

Elements can be categorized as noble gases, representative elements, transition metals, or inner transition metals based on their electron configurations.

How did chemists begin the process of organizing elements?

In 1829, J.W. Dobereiner organized the elements into groups of triads, 3 elements with similar chemical properties. In addition, he noticed that one element in each triad had properties with values the was midway between the other 2 elements. However, this organization method had one flaw: it couldn't accept newly discovered elements.

How are elements arranged in the modern periodic table?

In the modern periodic table, elements are arranged according to increasing atomic number.

Name two elements that have properties similar to those of the element sodium.

Lithium and potassium are both elements similar to those of sodium, because they are both in the same period as sodium.

What property did Mendeleev use to organize his periodic table?

Mendeleev arranged the elements according to increasing atomic mass.

Is this electron configuration a representative element, transition metal, or noble gas.

The electron configuration is that of Krypton, clearly a noble gas.

Why do the elements potassium and sodium have similar chemical properties?

The elements potassium and sodium have similar chemical properties because they have the same number of valence electrons (1).

What information can be included in a periodic table?

The periodic table contains much information. It systematically organizes the elements in a fashion that presents the similarities among elements in the same families. Moreover, the periodic table provides for periodic trends that can be visualized as one moves across rows and down columns. The periodic table also contains the chemical symbols of all elements, the atomic and mass numbers of each element, and sometimes the way electrons are distributed in the energy levels of the atoms. Periodic tables also usually use some system to show the state of matter displayed by each element at standard conditions. Lastly, the periodic table contains a line that separates nonmetals from metals and shows the metalloids in between the two main groups of elements. Sometimes, periodic tables also use color identification to distinguish the different groups of atoms.

Name the three broad classes of elements.

The three general classes of elements are metal, nonmetal, and metalloid.

Which of the following are transition metals: Cu, Sr, Cd, Au, Al, Ge, Co?

Transition metals belong to the d block. From the list of elements given, we see that Cu, Cd, Au, and Co are all transition elements, because they are in the d block.

Identify each element as a metal, metalloid, or nonmetal. a. gold b. silicon c. sulfur d. barium

a. Gold is a metal. b. Silicon is a metalloid c. Sulfur is a nonmetal. d. Barium is a metal.

Write the electron configuration of carbon.

carbon 1s2 2s2 2p2 or [He]2s2 2p2