1st Period Groups and Periods

Which pair of properties describes the elements in Group 18? (8.5C)

• They are chemically stable and liquid at room temperature.

• They have eight valence electrons and are flammable.

• They are magnetic and boil at low temperatures.

• They are gaseous at room temperature and chemically stable.

Element R and Element Q have the same number of valence electrons. These elements both have similar chemical behavior, but Element R has fewer energy levels than Element Q.Which statement best describes the positions of the two elements in the periodic table? (8.5C)

• The two elements are in the same period, with Element R the first element in the period and Element Q the last element.

• The two elements are side by side in the same period, with Element Q to the left of Element R.

• The two elements are in the same group, with Element R just above Element Q.

• The two elements are in the same group, with Element Q at the top of the group and Element R at the bottom.

What is the difference between the number of electrons in an atom of selenium, Se, and the number of electrons in an atom of aluminum, Al? (8.5A)

• 13

• 34

• 52

• 21

When trying to identify an unknown element, a scientist determines what other elements the unknown element reacts with chemically. Which property of the unknown element determines the other elements it reacts with? (8.5B)

• The total number of neutrons in the unknown element

• The total number of particles in the nucleus of the unknown element

• The number of protons in the nucleus of the unknown element

• The number of valence electrons in the unknown element

Aluminum, sulfur, and chlorine are elements found on the periodic table. Tests involving these three elements would show that at normal room temperature — (6.6A)

• sulfur is malleable and aluminum conducts electricity

• chlorine is malleable and conducts electricity

• aluminum is malleable and conducts electricity

• all three elements are malleable and conduct electricity

A chemist is identifying the elements present in a sample of seawater. What characteristic of an element’s atoms always determines the element’s identity? (8.5B)

• The number of protons

• The number of neutrons

• The location of valence electrons

• The number of valence electrons

Which two elements on the periodic table are in the same period? (8.5C)

• Sn and Rb

• K and Ba

• F and Cl

• Se and Te

A student is studying the ways different elements are similar to one another. Diagrams of atoms from four different elements are shown below.Which two atoms are of elements in the same group in the periodic table? (8.5C)

• Atom 1 and Atom 2

• Atom 2 and Atom 3

• Atom 1 and Atom 4

• Atom 3 and Atom 4

A researcher wants to experiment with an element that reacts like phosphorus (P) but has a greater atomic mass. Which element should the researcher select for the experiment? (8.5C)

• Nitrogen (N)

• Arsenic (As)

• Sulfur (S)

• Silicon (Si)

A model of an atom is shown. How many valence electrons does the above atom have? (8.5A)

• 5

• 2

• 11

• 3